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LIFELONG LEARNING
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Integrative Imaging
Supplement to the American Journal of Roentgenology
AJR March 2009, Vol. 192, No. 3, pp. S1–S64
AJR Integrative Imaging
LIFELONG LEARNING
FOR RADIOLOGY
CME and SAM Information
Three of the articles in this issue of AJR Integrative
Imaging offer SAM and CME credits.
CME Credit
The American Roentgen Ray Society (ARRS) is accredited by
the Accreditation Council on Continuing Medical Education
(ACCME) to sponsor continuing medical activities for physicians.
The ARRS designates this educational activity for a maximum of 4.5 credits toward the AMA Physician’s Recognition
Award. Each physician should claim only those credits that he
or she actually spent in the activity.
• Up to 1.5 CME credits may be claimed for Imaging of Lung
Transplantation: Self-Assessment Module.
• Up to 1.5 CME credits may be claimed for CT Virtual En-
doscopy in the Evaluation of Large Airway Disease: Self-Assessment Module.
• Up to 1.5 CME credits may be claimed for Radiologic Signs
in Thoracic Imaging: Case-Based Review and Self-Assessment
Module.
These CME articles consist of two parts: one, the text and related images appearing in this supplement; and two, the self-evaluation quiz, which is available online at www.arrs.org. You should
read the articles, review the accompanying images and refer to
the articles referenced in this supplement, then complete the selfevaluation quiz. To obtain CME credit you must complete the selfevaluation quiz online. Visit www.arrs.org and go to the left-hand
menu bar under Publications/Journals/SAM Articles. There is no
charge for ARRS members to participate in this program. Nonmembers pay a fee to access CME and SAM material.
Date of release: February 19, 2009
Expiration date: February 18, 2012
Estimated time of completion: 4.5 hours
In compliance with the Essentials and Standards of the ACCME,
authors of the CME activities in this publication are required to disclose all relevant financial relationships with any commercial
interest to the ARRS. The ACCME defines “relevant financial relationships” as financial relationships in any amount occurring
within the past 12 months that create a conflict of interest.
Drs. Agarwal, Attili,Chasen, Day, Dillon, Donnelly, Epstein, Holloway, Jan, Mueller, Ng, Parker, Patsios, Paul,
Strother, Thomas, and Worrell, have all indicated that they
have no commercial interests to disclose.
SAM and CME Credit
Imaging of Lung Transplantation: Self-Assessment Module. To
obtain 1 SAM credit and 1.5 CME credits, you must follow the
instructions on page SXX.
CT Virtual Endoscopy in the Evaluation of Large Airway Disease:
Self-Assessment Module. To obtain 1 SAM credit and 1.5 CME
credits, you must follow the instructions on page SXX.
Radiologic Signs in Thoracic Imaging: Case-Based Review and
Self-Assessment Module. To obtain 1 SAM credit and 1.5 CME
credits, you must follow the instructions on page SXX.
Imaging of Lung Transplantation: Self-Assessment Module, CT
Virtual Endoscopy in the Evaluation of Large Airway Disease: SelfAssessment Module, and Radiologic Signs in Thoracic Imaging:
Case-Based Review and Self-Assessment Module are qualified by
the American Board of Radiology (ABR) in meeting the criteria for self-assessment toward the purpose of fulfilling requirements in the ABR Maintenance of Certification. To obtain
SAM credit, visit www.arrs.org and go to the left-hand menu
bar under Publications/Journals/SAM Articles.
W COVER ART CREDIT: Mani Puthuran
British Museum
COVER ARTWORK SUBMISSIONS
If you would like to have your photograph or illustration considered for the front cover of AJR Integrative Imaging, please submit it via www.arrs.org.
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Integrative Imaging
LIFELONG LEARNING FOR RADIOLOGY
A supplement to the American Journal of Roentgenology
Editor in Chief, AJR
Thomas H. Berquist, MD
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Section Editor, AJR Integrative Imaging
Assistant Editors
Section Editors, AJR
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G. Donald Frey, PhD
Musculoskeletal Imaging
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Neuroradiology and Head and Neck Imaging
James M. Provenzale, MD
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King C. Li, MD, MBA
Pediatric Imaging
Beverly P. Wood, MD, MSEd, PhD
Education Committee Chair
CME Liaison to the AJR
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MOC Coordinating Committee
Breast Imaging
Cardiac Imaging
Critical Thinking
Gastrointestinal
General Content
Genitourinary Imaging
Musculoskeletal Disease and Trauma
Neuroradiology
Nuclear Medicine
Pediatric Imaging
Pulmonary Imaging
Vascular & Interventional Imaging
Ultrasound
Volume 192, No. 3, March 2009
Felix S. Chew, MD, EdM
Seattle, WA
Susanna I. Lee, MD, PhD
Pierre D. Maldjian, MD
Catherine C. Roberts, MD
Norman J. Beauchamp, MD
Gary J. Whitman, MD
Jannette Collins, MD
Katherine A. Klein, MD
Liane Philpotts, MD
Gautham P. Reddy, MD
John Eng, MD
Asra Khan, MD
Stephen Chan, MD
Aine Kelly, MD
Deborah A. Baumgarten, MD, MPH
Felix S. Chew, MD, Michael J. Tuite, MD
Pamela W. Schaefer, MD
Darlene Metter, MD
Beverly P. Wood, MD, MSEd, PhD
James G. Ravenel, MD
Brian S. Funaki, MD
Teresita L. Angtuaco, MD
Vascular and Interventional Radiology
Matthew A. Mauro, MD
Women’s Imaging
Marcia C. Javitt, MD
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AJR Integrative Imaging
LIFELONG LEARNING
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Instructions for Authors
A complete set of AJR Instructions for Authors, including information about figure processing and electronic submission requirements, can
be found at www.arrs.org.
AJR Integrative Imaging submissions should follow the formats outlined below.
1. Reviews and Self-Assessment Modules
Although these articles may have a variety of formats (see
specific types below), common elements include educational objectives, multiple-choice self-assessment questions that refer directly to the educational objectives, explanation of the correct
and incorrect responses, and references. It is expected that some
multiple-choice questions may be case-based. Each illustration
should have a detailed description, either in the legend or in the
text, and include the age, sex, and condition of the patient, as
well as a description of the technology used to produce the image
(e.g., endoluminal 3D CTC image of 32-year-old man with…).
Author instructions: The review portion of the manuscript
should have 5,000–10,000 words of text, 10–25 figure parts, and
as many references as needed. The self-assessment portion should
have a least 10 four-option multiple-choice questions with complete solutions. The multiple-choice questions should have a single best response, and should be acceptable to the American
Board of Radiology (ABR). The multiple-choice questions may
be used to introduce the case discussions, to assess comprehension, or both. The solution to each multiple-choice question
should explicitly state why each of the answer options is or is not
the best response, and should have at least one reference. Redundancy of information presented in the solutions with that presented in the article text is to be expected.
Type 1. Case-based: This format consists of a set of educational
case scenarios related by a theme. The case presentations consist
of the clinical presentation, the rationale for imaging, a description of the images, four-option multiple-choice questions, explanations of the best and incorrect responses, and concluding
commentary. The exact format depends on the particular case.
The theme that relates the cases may be any combination of
anatomy, clinical presentation, pathophysiology, technique, demographics, etc. These articles should have a minimum of six
case scenarios. The following is an example of a case-based review and SAM (Editor’s note: Fewer case scenarios were required at the time this SAM was qualified by the ABR):
• Chew FS. Radiology of the Hands: Review and Self-Assessment Module. AJR 2005; 184[suppl]:S157–S168
Type 2. Evidence-based: This format consists of discussions of
one or more clinical management issues. The scientific evidence
for different courses of management is presented in the context
of illustrative case scenarios. These articles should have a minimum of six case scenarios. The following is an example of an evidence-based review and accompanying self-assessment module
(Editor’s note: Fewer multiple choice questions were required at
the time this SAM was qualified by the ABR):
S484
• Attili AK, Cascade PN. CT and MRI of Coronary Artery Disease: Evidence-Based Review. AJR 2006; 187[suppl]: S483–S499
• Attili AK, Foral JM, Schoepf J, Cascade PN, Chew FS. CT
and MRI of Coronary Artery Disease: Self-Assessment Module. AJR 2006; 187[suppl]:S500–S504
Type 3. Pictorial essay (clinically or pathophysiology-based):
This format consists of an exposition on a clinically or pathophysiology-based topic with extensive illustrations. The following is an example of a pictorial review and self-assessment
module (Editor’s note: Fewer multiple-choice questions were required at the time this SAM was qualified by the ABR):
• Poon CS, Chang J-K, Swarnkar A, Johnson MH, Wasenko J.
Radiologic Diagnosis of Cerebral Venous Thrombosis: Pictorial Review. AJR 2007; 189[suppl]:S64–S75
• Poon CS, Chew FS. Radiologic Diagnosis of Cerebral
Venous Thrombosis: Self-Assessment Module. AJR 2007;
189[suppl]:S76–S78
Type 4. Review article: This format consists of a traditional review article with a large number of references. Illustrative cases
and multiple-choice questions may be used to introduce or review
topics. The following is an example of a review article and self-assessment module (Editor’s note: Fewer multiple-choice questions
were required at the time this SAM was qualified by the ABR):
• Momeni AK, Roberts CC, Chew FS. Imaging of Chronic and
Exotic Sinonasal Disease: Review. AJR 2007; 189[suppl]: S35–S45
• Momeni AK, Roberts CC, Chew FS. Imaging of Chronic
and Exotic Sinonasal Disease: Self-Assessment Module.
AJR 2007; 189[suppl]:S46–S48
Type 5. Self-assessment module without accompanying review:
This format consists of educational objectives, a list of required
educational activities that are external to the SAM itself (such as
published articles or Web content), 10 or more multiple-choice
questions that refer to the educational objectives and activities,
and complete solutions that explain each answer option and provide references.
The following is an example of a self-assessment module without accompanying review (Editor’s note: Fewer multiple-choice
questions were required at the time this SAM was qualified by
the ABR):
• Ko JP, Roberts CC, Berger WG, Chew FS. Imaging Evaluation of the Solitary Pulmonary Nodule: Self-Assessment
Module. AJR 2007; 188[suppl]:S1–S4
2. Radiological Reasoning
These are case presentations that step the reader through an
expert’s analysis of a difficult case. The case is presented progresAJR:187, September 2006
sively, with the expert’s thought process described in detail. Concluding comments tie up loose ends and provide references and
additional relevant factual material. Clinical reasoning presentations should fit on approximately five journal pages. The title of
the article should reflect the clinical or imaging presentation, not
the specific pathologic diagnosis. The abstract should include the
diagnosis and the take-home message of the article.
Author instructions: 2,000–4,000 words, NOT including the
multiple choice questions and solutions, 5–10 figure parts. Three
voices: case presenter, expert discussant, and expert commentator. Do not include a review of the literature because these may be
found elsewhere (e.g., textbooks and actual review articles). Each
article should be followed by five four-option multiple-choice
questions that will be used to assess comprehension. Each of the
best and non-best responses should be explicitly explained in the
solutions, and each solution should have at least one reference.
Radiological reasoning articles are often used as required reading for self-assessment modules (see SAM Type 5, above), therefore, authors of radiological reasoning manuscripts are strongly
encouraged to submit a companion self-assessment module
manuscript at the same time. The following is an example of a radiological reasoning article and accompanying self-assessment
module (Editor’s note: Fewer multiple choice questions were required at the time this SAM was qualified by the ABR):
• Liu PT. Radiological Reasoning: Acutely Painful Swollen
Finger. AJR 2007; 188:[suppl]S13–S17
• Roberts CC, Liu PT, Chew FS. Imaging Evaluation of Tendon Sheath Disease: Self-Assessment Module. AJR 2007;
188:S10–S12
3. Teaching File
Teaching file cases are standard cases that are well illustrated, typically with an interesting twist. Unlike case reports,
S485
which seek to extend the frontiers of knowledge, teaching file
cases are intended as exemplars of known appearances and presentations of disease, with the goal of educating the reader. The
standard presentation includes clinical history, clinical images,
radiologic description, focused differential diagnosis, final diagnosis, and commentary. An abstract should be prepared that
provides an educational objective and a conclusion. The title of
the article should reflect the clinical or imaging presentation
rather than the specific pathologic diagnosis. Authors should
provide two four-option multiple-choice questions with complete solutions. Each of the best and non-best responses should
be explicitly explained in the solutions, and each solution
should have at least one reference. Authors will need to provide
indexing terms and coding.
Teaching file cases should be 1,000–2,000 words, NOT including the multiple-choice questions and solutions, and typically no more than eight figure parts. Some teaching file
manuscripts may be selected for publication as Web exclusives.
Teaching File cases are often used as required reading for selfassessment modules (see SAM Type 5, above), therefore, teaching file manuscripts that are amenable to such use or are
accompanied by a companion self-assessment module manuscript are much more likely to receive serious consideration.
The following is an example of a teaching file article and accompanying self-assessment module (Editor’s note: Fewer multiple choice questions were required at the time this SAM was
qualified by the ABR):
• Sutcliffe JB III, Bui-Mansfield LT. AJR Teaching File: Intermittent Claudication of the Lower Extremity in a Young
Patient. AJR 2007; 189[suppl]:S17–S20
• Chew FS, Bui-Mansfield LT. Imaging Popliteal Artery Disease in Young Adults with Claudication: Self-Assessment
Module. AJR 2007; 189[suppl]:S13–S16
AJR:187, March 2006
AJR Integrative Imaging
LIFELONG LEARNING
FOR RADIOLOGY
Integrative Imaging
LIFELONG LEARNING FOR RADIOLOGY
A supplement to the American Journal of Roentgenology
Volume 192, No. 1, March 2009
Table of Contents
Imaging of Lung Transplantation: Review.. .............................................................. SXX
Ng YL, Paul N, Patsios D, et al; DOI:10.2214/AJR.07.7061
1.5 CME
1.0 SAM
Imaging of Lung Transplantation: Self-Assessment Module.................................. SXX
Ng YL, Paul N, Patsios D, et al.; DOI:10.2214/AJR.07.7130
CT Virtual Endoscopy in the Evaluation of Large Airway Disease: Review. ............... SXX
Thomas BP, Strother MK, Donnelly EF, Worrell JA; DOI:10.2214/AJR.07.7077
1.5 CME
1.0 SAM
1.5 CME
1.0 SAM
CT Virtual Endoscopy in the Evaluation of Large Airway Disease:
Self-Assessment Module........................................................................................ SXX
Thomas BP, Strother MK, Donnelly EF, Worrell JA; DOI:10.2214/AJR.07.7129
Radiologic Signs in Thoracic Imaging: Case-Based Review and
Self-Assessment Module........................................................................................ SXX
Parker MS, Chasen MH, Paul N; DOI:10.2214/AJR.07.7081
AJR Teaching File: Right Atrial Mass in a Woman with Dyspnea on Exertion. ......... SXX
Holloway BJ, Agarwal PP; DOI:10.2214/AJR.07.7066
AJR Teaching File: Right Atrial Mass in a Woman with Uterine Fibroids.................. SXX
Jan S, Dillon EH, Epstein NF; DOI:10.2214/AJR.07.7080
AJR Teaching File: Asymptomatic Man with Giant Negative T Waves on ECG.......... SXX
Attili A, Mueller GC, Day SM; DOI:10.2214/AJR.07.7116
Author Correction....................................................................................................... SXX
AJR Integrative Imaging
LIFELONG LEARNING
FOR RADIOLOGY
Imaging of Lung Transplantation: Review
Yuen Li Ng1, 2, Narinder Paul3, Demetris Patsios3, Anna Walsham4, Tae-Bong Chung3, Shaf Keshavjee5, Gordon Weisbrod3
OBJECTIVE
Lung transplantation is an established treatment for endstage pulmonary disease. Complications of lung transplantation include airway stenosis and dehiscence, reimplantation response, acute rejection, infection, posttransplantation
lymphoproliferative disorder, and bronchiolitis obliterans
syndrome. The incidence of graft rejection and airway
anastomosis experienced in the early years of lung transplantation have been significantly reduced by advances in
immunosuppression and surgical techniques. Infection is
currently the most common cause of mortality during the
first 6 months after transplantation, whereas chronic rejection or obliterative bronchiolitis is the most common cause
of mortality thereafter. This article reviews the radiologic
findings of different surgical techniques as well as the common early and late complications of lung transplantation.
CONCLUSION
Radiology plays a pivotal role in the diagnosis and management of complications of lung transplantation. Advancements in surgical technique and medical therapy influence the spectrum of expected radiologic findings.
Familiarity with the radiologic appearances of common
surgical techniques and complications of lung transplantation is important.
Introduction
The first successful isolated single-lung transplantation
procedure was performed by the Toronto General Hospital
group at the University of Toronto in 1983 [1]. Lung transplantation has since become an established treatment for
end-stage pulmonary disease [2]. The registry of the International Society for Heart and Lung Transplantation (ISHLT)
recorded an all-time high of 2,169 lung transplantations in
2005 [3]. The main indications for lung transplantation in the
18 months before this writing were chronic obstructive pulmonary disease (COPD, 38%), idiopathic pulmonary fibrosis
(IPF, 19%), cystic fibrosis (16%), and α1-antitrypsin deficiency emphysema (8%) (Table 1). The reported survival
rates from January 1994 to June 2005 were 87% at 3 months,
78% at 1 year, 62% at 3 years, 50% at 5 years, and 26% at 10
years [3]. Overall, sepsis was the predominant cause of death
in the first 6 months after transplantation, whereas chronic
graft failure was the main cause of death after 6 months [2].
Surgical Techniques
Single-lung transplantation is usually performed through
a posterolateral thoracotomy. On the other hand, bilateral
lung transplantation is generally performed through a
transverse thoracosternotomy involving bilateral sequential single-lung transplantation [2]. The technique of en
bloc double-lung transplantation with tracheal anastomosis
is now rarely performed because of the increased rate of
anastomotic dehiscence.
Bilateral lung transplantation accounted for 63% of lung
transplantation procedures in 2005 [3]. Bilateral lung transplantation is usually performed for chronic pulmonary sepsis such as cystic fibrosis and bronchiectasis (Table 1). It is
also the dominant procedure for primary pulmonary hypertension. Bilateral lung transplantation for both COPD and
IPF has increased in recent years. This trend may be explained by the higher overall survival rate after bilateral
transplantation, by the increased lung function to buffer
complications, and by institutional preferences and practices. The lung transplantation program at our institution
prefers the use of bilateral lung transplants [2, 3].
Airway anastomotic dehiscence was one of the major obstacles to success in the early years of lung transplantation
[4]. The early surgical techniques aimed to reduce the incidence of bronchial dehiscence by improved healing of the
anastomoses using intercostal muscle, pericardium, or
omentum to wrap the end-to-end bronchial anastomoses [5,
6]. However, the development of significant complications
such as diaphragmatic hernias associated with the omental
Keywords: lung transplantation
DOI:10.2214/AJR.07.7061
Received November 29, 2007; accepted after revision February 19, 2008.
CT Unit, Jubilee Wing, Department of Clinical Radiology, Leeds General Infirmary, Leeds LS1 3EX, West Yorkshire, United Kingdom.
1
Present address: Department of Diagnostic Radiology, Singapore General Hospital, Outram Rd., Singapore 169608. Address correspondence to
Y. L. Ng ([email protected]).
2
Joint Department of Medical Imaging, Thoracic Division, University Health Network and Mount Sinai Hospital, Toronto General Hospital, Toronto, ON, Canada.
3
Department of Clinical Radiology, Hope Hospital, Manchester, United Kingdom.
4
Division of Thoracic Surgery and Toronto Lung Transplant Program, Toronto General Hospital, Toronto, ON, Canada.
5
AJR 2009;192:SXX–SXX 0361–803X/09/1923–SX © American Roentgen Ray Society
S1
AJR:192, March 2009
Ng et al.
TABLE 1: Distribution of Diagnoses and Procedures Among Adult Lung Transplant Recipients
(January 1995 to June 2006) [3]
Diagnosis
Single Lung Transplants
Double Lung Transplants
Chronic obstructive pulmonary disease or emphysema
4,305 (52)
2,225 (24)
Idiopathic pulmonary fibrosis
Total
6,530 (38)
2,193 (26)
1,217 (13)
2,410 (19)
Cystic fibrosis
167 (2.0)
2,722 (29)
2,889 (16)
Alpha1-antitrypsin deficiency emphysema
626 (7.5)
795 (8.5)
1,421 (8.1)
Primary pulmonary hypertension
65 (0.8)
575 (6.2)
640 (3.6)
178 (2.1)
260 (2.8)
438 (2.5)
Bronchiectasis
30 (0.4)
473 (5.1)
503 (2.6)
Lymphangioleiomyomatosis
59 (0.7)
116 (1.2)
175 (1)
7 (0.1)
12 (0.1)
Sarcoidosis
Cancer
19 (0.1)
Note—Data are numbers (%) of patients. Reprinted with permission from [3].
A
B
C
D
Fig. 1—Bronchial anastomosis.
A, Schematic diagram shows end-to-end and “telescope” anastomoses.
B, 41-year-old woman who underwent bilateral lung transplantation in 1980s. CT scan shows area of fat attenuation (asterisk) in thorax, representing omentum used
to wrap bronchial end-to-end anastomoses.
C and D, Axial (C) and coronal (D) CT reformations show normal posttransplantation appearance of telescope anastomoses. Note bronchial overlap; smaller bronchus
is “telescoped” into larger bronchus. Internal margin of anastomosis is not sutured and may result in endoluminal flap (arrowhead, D).
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AJR:192, March 2009
Lung Transplantation
wrap technique [6] encouraged the refinement of surgical
techniques and the development of the “telescope technique” (Fig. 1), which does not require a wrap procedure
[7]. With further advances in surgical technique and donor
preservation, end-to-end anastomoses without a wrap procedure have been performed with good success [2, 8].
The telescope technique is preferentially used in our institution when there is bronchial size discrepancy. The
smaller bronchus is intussuscepted into the larger bronchus,
which then helps to maintain an adequate bronchial lumen
and act as an anastomotic stent. When bronchial size is
equivalent, end-to-end anastomosis is performed [2]. After
bronchial anastomosis, the pulmonary artery and vein
anastomoses are performed. The bronchial arterial circulation is not reestablished during transplantation, and rear­
terialization via recipient bronchial arteries requires an estimated 2–4 weeks after surgery [6, 9].
Airway Complications
The incidence of airway complications has decreased
with improved surgical and donor preservation techniques,
immunosuppression, and posttransplantation surveillance
[4, 8, 10]. Airway complications have been estimated to occur in approximately 5–15% of lung transplants. [4, 6, 9,
10]. The healing of bronchial anastomoses relies on healthy
retrograde collateral perfusion from the pulmonary arterial
circulation in the initial postoperative period because bronchial arteries are not reanastomosed during transplantation
[6, 11]. A suboptimal vascular supply predisposes to ischemia and subsequent ulceration, leading to bronchial dehiscence, stricture formation, and bronchomalacia [6, 12]. Infection and rejection may also play a role.
Airway complications such as bronchial dehiscence and
stricture are usually diagnosed by bronchoscopy. However,
CT is valuable and is more sensitive than chest radiography
in the diagnosis of airway complications [13].
Fig. 2—Bronchial dehiscence in 28-year-old woman 11 days after bilateral lung
transplantation. Patient developed persistent bilateral pneumothoraces (curved
arrows) despite bilateral thoracostomy drains (arrowheads). Cause was revealed on CT, which shows focal defect at right bronchial anastomosis and extraluminal air (straight arrow). Note also left lower lobe pneumonia causing
consolidation and atelectasis.
Bronchial dehiscence is the most common airway complication in the early postoperative period, affecting 2–3% of cases
[2, 6, 12] and typically occurring 2–4 weeks after transplantation [6, 9, 10]. CT typically shows the presence of extraluminal
gas and, occasionally, the focal bronchial wall defect that is
pathognomonic of this condition [14] (Fig. 2). Indirect signs of
bronchial dehiscence include the presence of a new or persistent air leak, pneumothorax, and pneumomediastinum.
Bronchial stricture formation is seen in approximately 10%
of cases; it occurs later in the postoperative period, an average
of 3 months after surgery [6, 9, 10]. There is thought to be an
increased incidence of stricture formation with the use of the
telescope anastomosis technique [8]. CT with multiplanar reconstructions is helpful in depicting strictures and webs and is
A
B
Fig. 3—Bronchial stricture in 36-year-old man 6 weeks after bilateral lung transplantation.
A and B, Low-dose (50-mA) axial CT scan (A) and coronal reconstruction (B) show focal tight stenosis at left bronchial anastomosis (arrows).
AJR:192, March 2009
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Ng et al.
A
B
Fig. 4—Pneumothorax after transbronchial biopsy in 45-year-old man. This patient experienced right pleuritic pain after surveillance bronchoscopy and trans­
bronchial biopsy.
A, Immediate chest radiograph shows localized right basal pneumothorax (asterisk).
B, Subsequent CT scan confirms localized right basal hydropneumothorax associated with right lower lobe atelectasis and bronchiectasis.
particularly useful in assessing the extent of bronchial stenoses in order to plan bronchoscopic stent insertion [15] (Fig 3).
Vascular Complications
Vascular anastomotic stenoses, which are more common
at the arterial anastomoses, are rare, occurring in fewer
than 4% of cases [16]. The risk of pulmonary infarction is
greatest in the immediate postoperative period because the
transplanted lung does not have an alternative bronchial
blood supply. Perfusion scintigraphy may aid in making the
diagnosis. The prognosis is usually dismal, but successful
outcomes have recently been reported with angioplasty and
stent insertion [8].
Pulmonary torsion is a rare but serious complication that
may occur in the immediate postoperative period. Imaging
features of pulmonary torsion are related to the torquing of
the hilar structures, the airway, and the vasculature, and include a collapsed lobe (due to airway compromise) or an expansile consolidated lobe (due to hemorrhagic infarction) in
an atypical location [19]. Other features that may be present
are bronchial cutoff, inappropriate hilar displacement associated with an atelectatic lobe, abnormal position of pulmonary vasculature and bronchi, rapid opacification of a lobe or
Mechanical Complications
Size mismatch between donor lung and recipient thoracic
cavity may cause mechanical complications. Most centers
will accept size differences of within 25% [17, 18]. If the donor lung is too large for the recipient, distortion of airways
and atelectasis may occur, with retained secretions and secondary infections. This may lead to scarring. The oversized
lung graft may be intraoperatively reduced to match the capacity of the recipient. If the donor lung is too small for the
recipient, graft hyperexpansion may lead to hemodynamic
compromise, limited exercise tolerance, or frank pulmonary
hypertension, all because of an inadequate vascular bed [17].
In patients with emphysema who undergo single-lung transplantation, the small graft may be compressed by the emphysematous native lung, resulting in restrictive pulmonary
function [18]. Lung volume reduction surgery may be performed during the transplantation procedure.
S4
Fig. 5—Pleural empyema and hematoma in 49-year-old man whose condition
deteriorated clinically 8 days after bilateral lung transplantation. CT scan reveals focal fluid collection (single asterisk) in left anterior hemithorax containing gas, suggestive of empyema. Note also large focal collection in right basal
hemithorax with higher-attenuation hematoma (double asterisks). Findings
were confirmed at thoracotomy.
AJR:192, March 2009
Lung Transplantation
Day 0
Reimplantation response
Day 7
Bacterial infection
Acute rejection
Fungal infection
4 wks
Viral infection
3 mo
6 mo
1y
PTLD
Obliterative bronchiolitis
Recurrent disease
Upper lobe fibrosis
2y
Fig. 6—Diagram shows typical time course for onset of pulmonary parenchymal
complications after lung transplantation. PTLD = posttransplantation lympho­
proliferative disorder.
lung, and change in position of an opacified lobe on sequential
radiographs. Once pulmonary torsion is suspected, immediate
surgery is indicated to avoid death from lobar infarction.
Pleural Complications
Pleural complications are seen in 22–34% of patients after transplantation [20, 21]. Bilateral-lung and heart–lung
transplantations frequently result in a single communicating pleural space. Therefore, fluid and gas collections are
often bilateral [8].
Pneumothorax is the most common pleural complication; it usually resolves with the insertion of thoracostomy
drains [8, 21]. New, persistent, or enlarging pneumothoraces
should prompt further investigations to elucidate the cause
of the air leak (Fig. 2). Pneumothorax may also occur after
transbronchial biopsy (Fig. 4).
Pleural effusions develop in almost all patients because
of increased capillary permeability and impaired lymphatic
clearance of the transplanted lung [12, 20]. They are usually self-limiting and resolve within 2 weeks. Persistent or
delayed effusions suggest complicated effusions such as empyema, organized hematoma, rejection, and posttransplantation lymphoproliferative disorder (PTLD). Empyema occurs in approximately 4% of patients and may affect both
hemithoraces, with potential disastrous consequences [8,
20] because it is the only pleural complication associated
with an increased mortality rate [21]. Therefore, empyema
should be excluded in the presence of a new or enlarging
pleural effusion (Fig. 5).
Pulmonary Parenchymal Complications
Many pulmonary parenchymal complications after lung
transplantation have nonspecific radiologic findings. Correlation with the time interval from transplantation is helpful
to narrow the differential diagnoses (Fig. 6). Clinical correlation and bronchoscopy with transbronchial biopsy are
also often required.
Reimplantation Response
Reimplantation response, also known as reperfusion edema, is a form of noncardiogenic pulmonary edema that occurs in more than 95% of patients [22] (Fig. 7). It frequently begins by postoperative day 1, is always present by day 3,
peaks by day 4 or 5, and resolves by day 10 [8, 11]. Persistence beyond the first week suggests infection or acute rejection. Reimplantation response is usually diagnosed after
A
B
Fig. 7—Reimplantation response in 33-year-old woman 2 days after bilateral lung transplantation.
A, Chest radiograph shows typical features of reimplantation response: bilateral perihilar and basal consolidation.
B, CT scan shows bilateral patchy ground-glass opacities and septal thickening in addition to consolidation.
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Ng et al.
Fig. 8—Acute rejection diagnosed on transbronchial biopsy in 51-year-old
woman 7 days after bilateral lung transplantation.
A, Portable chest radiograph shows nonspecific pulmonary opacities in perihilar, mid, and lower lung bilaterally.
B and C, CT images show bilateral patchy ground-glass opacities, consolidation, and interlobular septal thickening (arrows, B).
A
B
C
exclusion of left ventricular failure, fluid overload, transplant rejection, and infection [22, 23].
Chest radiography and CT typically show bilateral perihilar and basal air-space consolidation [22]. The pathogenesis is probably multifactorial: increased vascular permeability due to ischemia and subsequent reperfusion, lymph­atic
interruption, lung denervation, decreased surfactant production, and surgical trauma [12].
persisting, or progressive perihilar and basal opacities or
pleural effusions with septal lines 5–10 days after transplantation without other signs of left ventricular failure is
suggestive of acute rejection [8, 25]. CT findings include
ground-glass opacities, interlobular septal thickening, nodules, consolidation, and volume loss. Ground-glass opacities
are often patchy and localized in mild rejection but widespread in severe rejection [26]. However, CT has limited accuracy in the diagnosis or grading of severity of acute rejection [24].
Patients may be asymptomatic or may present with dysp­
nea, fever, leukocytosis, and decreased exercise tolerance.
Investigations reveal a decrease in arterial oxygenation and
forced expiratory volume in 1 second (FEV1). The most useful feature is the dramatic clinical and radiographic response to corticosteroids and increased immunosuppression
[8, 23]. Transbronchial biopsy is often performed to confirm
the diagnosis and to exclude infection [8].
Acute Rejection
Acute rejection usually occurs within the first 3 weeks, typically between postoperative days 5 and 10 [8] (Fig. 8). Most
patients experience two or three significant rejection episodes
in the first 3 months after transplantation [12]. Repeated episodes of acute rejection are associated with an increased risk of
chronic rejection (i.e., bronchiolitis obliterans syndrome) [24].
The radiographic features may be similar to those of reimplantation response and infection. The presence of new,
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Lung Transplantation
A
B
Fig. 9—Infections with Aspergillus organisms in two patients.
A, 26-year-old man developed aspergillosis 1 month after bilateral lung transplantation. CT scan shows multiple nodules (curved arrows), some with surrounding
ground-glass halo sign (arrowheads) and cavitation (straight arrow).
B, CT scan in 37-year-old man 3 weeks after bilateral lung transplantation shows patchy ground-glass opacities in left lower lobe. Culture of bronchial washings was
positive for Aspergillus organisms.
A
B
Fig. 10—Cytomegalovirus pneumonia in seropositive 44-year-old man after bilateral lung transplantation.
A, Chest radiograph shows nonspecific bilateral basal patchy and hazy opacities.
B, CT scan shows bilateral patchy ground-glass attenuation and micronodules.
Infection
Infection is the most common complication after transplantation and is a major cause of morbidity and mortality
[2]. Patients have increased susceptibility to infection because of immunosuppression, lung denervation and loss of
the cough reflex, impaired mucociliary function, and lymphatic drainage [8, 27].
Bacterial infections predominate in the first 4 weeks after
transplantation; viral infections are generally not seen until
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the following month. Fungal infections can occur at any period after transplantation. Pneumocystis pneumonia is now
uncommon because of the routine use of trimethoprimsulfamethoxazole prophylaxis [12].
Bacterial Infection
Bacterial infections account for at least 50% of all infections [11]. The incidence is highest in the first month, but remains a significant complication throughout the patient’s life
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Ng et al.
A
B
Fig. 11—Posttransplantation lymphoproliferative disorder (PTLD) in 26-year-old man 4 months after bilateral lung transplantation.
A, Multiple lung nodules were detected incidentally on surveillance chest radiograph.
B, CT scan shows multiple nodules with surrounding halo of ground glass (arrows). Percutaneous CT-guided biopsy confirmed diagnosis of PTLD.
[8, 27]. Death is unusual in the immediate postoperative period because of the wide use of broad-spectrum antibiotics.
The most common causative organisms are gram-negative
bacilli such as Klebsiella organisms, Pseudomonas aeruginosa,
and Enterobacter cloacae. Gram-positive organisms such as
Staphylococcus aureus are also observed [8, 11]. In patients
with cystic fibrosis, the presence of Burkholderia cepacia is
associated with severe postoperative infections and reduced
survival rates [2].
Radiologic features are similar to those of nontransplant
patients: lobar or multifocal consolidation, ground glass
opacity, cavitation, and lung nodules [8, 27].
Fungal Infection
Fungal infections, most commonly Candida and Aspergillus organisms, usually occur between 10 and 60 days after transplantation [27]. They are less common but are associated with a higher mortality rate than viral infections
[8]. Candida species frequently colonize the airways, but invasive pulmonary infection is uncommon.
Aspergillosis is more prevalent in lung transplantation patients than in other immunocompromised patients. Locally
invasive or disseminated infection with Aspergillus organisms
accounts for 2–33% of infections after lung transplantation
and 4–7% of all lung transplantation deaths [27]. Aspergillus
organisms can cause indolent pneumonia or fulminant angioinvasive infection with systemic dissemination (Fig. 9). CT
commonly reveals a combination of ill-defined nodules, cavitary opacities, consolidation, and ground-glass opacity [27].
Symptoms are nonspecific and include fever, cough, pleuritic
chest pain, and hemoptysis [8].
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Aspergillus infections in the airway are seen in 5% of patients, mostly in the first 6 months. They are usually asymp­
tomatic and are detected on surveillance bronchoscopy.
Such an infection may cause ulcerative tracheobronchitis
that is usually radiologically occult and can lead to bronchial dehiscence, stenosis, or bronchomalacia [8].
Viral Infection
Cytomegalovirus (CMV) is the second most common
cause of pneumonia in lung transplantation patients and is
the most common opportunistic infection [8] (Fig. 10). CMV
pneumonia most commonly occurs between 1 and 12
months, with a peak incidence at 1–4 months [27].
Chest radiographs may be normal or may show diffuse
parenchymal haziness or reticulonodular interstitial opacities. CT findings include areas of ground-glass attenuation,
micronodules, consolidation, reticulation, and small pleural
effusions [8, 27].
Patients may be asymptomatic or develop fulminant
pneumonia. Clinical manifestations include dyspnea, fever,
cough, and malaise [12]. CMV pneumonia is associated with
an increased risk of superadded bacterial and fungal infections as well as the development of bronchiolitis obliterans
syndrome. Diagnosis can be made by bronchoalveolar lavage and transbronchial biopsy.
Primary infection occurs in CMV-seronegative recipients
who receive a graft from a seropositive donor. Infection develops in more than 90% and is serious in 50–60% of cases
[27]. Thus, CMV matching between donor and recipient is
performed whenever possible. Secondary infection develops
from reactivation of a latent virus after immunosuppres-
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Lung Transplantation
A
B
C
D
Fig. 12—Obliterative bronchiolitis in two patients.
A and B, Chest radiograph (A) in 35-year-old woman 9 months after bilateral lung transplantation shows decreased vascular markings and increased lung volumes.
CT scan (B) shows minor bronchial dilatation and mosaic attenuation. Transbronchial biopsy revealed obliterative bronchiolitis.
C and D, Inspiratory (C, 50 mAs) and expiratory (D, 20 mAs) CT scans show bronchial dilatation and air trapping in right lower lobe in 45-year-old man with known
obliterative bronchiolitis.
sion or from infection with a different CMV strain and is
usually less serious than the primary infection [8].
Other viral agents include herpes simplex virus, adenovirus, and respiratory syncytial virus.
Posttransplantation Lymphoproliferative
Disorder
PTLD is a spectrum of diseases that vary from a histologically benign polyclonal lymphoid proliferation to aggressive high-grade lymphoma [28]. It may manifest from 1
month to several years after transplantation but tends to
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occur within the first year, peaking at 3–4 months [23] (Fig.
11). The incidence is approximately 5% (range, 1.8–20%),
and it is more common with lung transplantation than with
other solid organ transplantations [11, 28]. The variability
in the incidence probably reflects differences in immunosuppression, ages of the study population, rates of EbsteinBarr viral (EBV) infections, and CMV prophylaxis.
Radiographically, PTLD usually manifests as solitary or
multiple pulmonary nodules or masses [28]. Extrapulmonary involvement—hilar or mediastinal adenopathy, thymic enlargement, pleural effusions, and pericardial mass-
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Ng et al.
A
C
es—is less common [11]. Clinical manifestations include
low-grade fever, lethargy, and weight loss. Patients may
also be asymptomatic.
PTLD is thought to be secondary to B-lymphocyte proliferation in response to EBV infection [11]. It is more com-
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B
Fig. 13—Recurrent disease in three patients.
A, Recurrent disease in 52-year-old woman 2 years after bilateral lung transplantation for sarcoidosis. CT scan shows nonspecific opacities in right lower
lobe; transbronchial biopsy revealed noncaseating granulomas.
B, 47-year-old woman with lymphangioleiomyomatosis (LAM) underwent bilateral lung transplantation. She developed chylothorax (arrow indicates fat–fluid
level) and retroperitoneal lymphadenopathy, which proved at histology to be
recurrent LAM.
C, 58-year-old woman underwent bilateral lung transplantation 18 months earlier for multifocal bronchioloalveolar carcinoma. CT scan shows multiple nodules. Transbronchial biopsy confirmed recurrent disease.
monly seen in EBV-seronegative recipients who receive an
EBV-seropositive donor lung. Aggressive immunosuppression regimens are also thought to be a cause [28]. Most cases respond to antiviral agents (e.g., acyclovir) and a reduction or cessation of immunosuppressive therapy.
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Lung Transplantation
A
B
Fig. 14—56-year-old man who developed bilateral upper lobe fibrosis 2 years after bilateral lung transplantation.
A, Chest radiograph shows bilateral upper lobe reticular opacities and volume loss.
B, CT scan shows coarse reticulation, architectural distortion, traction bronchiectasis (arrowhead), and honeycombing (arrow).
Obliterative Bronchiolitis
Obliterative bronchiolitis is thought to be a manifestation of chronic rejection, affecting up to 50% of patients
(Fig. 12). It is a major source of morbidity and mortality
and is now the greatest limitation to long-term survival after lung transplantation [2, 8, 11]. It usually develops within 6–18 months after transplantation but may occur as
early as the second month. Significant association with previous multiple episodes of acute rejection and CMV pneumonia has been reported. Other potential risk factors include other lung infections, gastroesophageal reflux, and
human leukocyte antigen mismatching [29].
Obliterative bronchiolitis is a histologic diagnosis; changes affect the small airways in a patchy distribution. Transbronchial biopsy may not be diagnostic, particularly in the
early stages [30]. Therefore, the disorder is frequently diagnosed clinically, using the term “bronchiolitis obliterans
syndrome,” on the basis of an otherwise unexplained decline in lung function [29]. Patients generally present with
a cough and worsening dyspnea [11].
The chest radiograph may be normal or may show attenuated pulmonary vessels, bronchial cuffing, subsegmental
atelectasis, and irregular linear opacities [13, 31]. Lung volumes can be normal or mildly increased. CT typically shows
bronchial dilatation, bronchial wall thickening, and mosaic
attenuation that are most marked in the lower lobes [31].
Air trapping is frequently depicted on expiratory CT in patients with obliterative bronchiolitis and can also be seen on
inspiratory CT in areas of lower attenuation with attenuated pulmonary vessels. However, the presence of air trap-
AJR:192, March 2009
ping is of limited sensitivity for the early diagnosis of obliterative bronchiolitis [32].
Recurrent Disease
Recurrent disease in the transplanted lung is uncommon,
affecting approximately 1% of recipients. Sarcoidosis, lymph­
angioleiomyomatosis, bronchioloalveolar carcinoma, and
Langerhans cell histiocytosis have been reported to recur in
the transplanted lung [8, 33]. The radiologic features of recurrent disease in the donor lung are similar to those of the
original disease, but they may mimic other posttransplantation complications such as infection, rejection, and PTLD.
Sarcoidosis is the most commonly reported disease to recur,
with a frequency of 35% [34] (Fig. 13A). Recurrence of sarcoidosis has been reported as early as 2 weeks and as late as 2
years after transplantation. It is an incidental finding at transbronchial lung biopsy in most cases. Transbronchial biopsy
shows multiple noncaseating giant cell epithelioid granulomas.
Because granulomas can also be seen with mycobacterial or
fungal infection, it is important to exclude these diagnoses. A
negative transbronchial lung biopsy does not exclude recurrent sarcoidosis because of the patchy nature of the disease.
Patients who have undergone lung transplantation for
lymphangioleiomyomatosis have increased morbidity and
mortality due to complications related to their underlying
disease—for example, native lung pneumothorax, chylothorax, chylous ascites, hemorrhagic renal angiomyolipomas,
and recurrence of disease—from 1 to 5 years after transplantation [34] (Fig. 13B).
Recurrence of bronchioloalveolar carcinoma has occurred
in approximately 50% of patients who survive the trans-
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Ng et al.
A
B
Fig. 15—After transbronchial lung biopsy, nodules are confined to one lung because surveillance transbronchial biopsies are only performed from one lung, usually
the right, at our institution.
A, 42-year-old man who underwent surveillance bronchoscopy and transbronchial biopsy 7 days before surveillance CT, which showed cavitary nodules (arrowheads) surrounded by ground-glass attenuation.
B, 39-year-old man who underwent surveillance transbronchial biopsy 3 days before surveillance CT, which showed solid nodules (arrows) surrounded by groundglass attenuation.
plantation [33] (Fig.13C). Recurrence is usually limited to a
transplant graft and is slow-growing despite immunosuppression. Lung transplantation for the treatment of multifocal bronchioloalveolar carcinoma is not widely established,
and represents only approximately 0.1% of transplantations
recorded by the ISHLT [3] (Table 1). Lung transplantation is
unlikely to be curative but can achieve a 5-year survival rate
of 39%, which is similar to that for other end-stage pulmonary diseases [33].
Upper Lobe Fibrosis
Upper lobe fibrosis is uncommon, reported to occur 18–72
months (average, 42 months) after lung transplantation
[35] (Fig. 14). The exact pathogenesis is unknown but is hypothesized to be a rare manifestation of chronic rejection.
Pathologic assessment may show nonspecific inflammation
and fibrosis.
High-resolution CT findings include interlobular septal
thickening, gradual development of coarse reticular opacities, and mild peripheral ground-glass opacities. The progression of established fibrosis may occur with traction
bronchiectasis, honeycombing, architectural distortion,
and volume loss. The upper lobes are initially involved, with
the subsequent development of smaller volumes of fibrosis
in the superior segments of the lower lobes [35]. The basal
segments are minimally involved.
S12
Patients develop progressive dyspnea. Pulmonary function
tests may show a mixed obstructive and restrictive pattern.
Complications After Transbronchial Biopsy
Solid and cavitary nodules (2–15 mm) with surrounding
ground-glass attenuation may be identified on CT up to 1
month after transbronchial biopsy [36] (Fig. 15). The
ground-glass attenuation represents hemorrhage secondary
to biopsy. The nodules may not be immediately evident on
chest radiographs. The temporal relationship to the biopsy
and the location at known biopsy sites should prevent confusion with infection or rejection.
Summary
Radiology plays a pivotal role in the diagnosis and management of complications of lung transplantation. Radiologists should be familiar with the radiologic appearances of
common surgical techniques as well as those of complications of lung transplantation. Because the radiologic pattern of disease may be nonspecific, it is critical to know the
time course from lung transplantation and relevant postoperative history in order to generate a clinically useful and
relevant radiologic opinion.
References
1.Toronto Lung Transplant Group. Unilateral lung transplantation for pulmonary
fibrosis. N Engl J Med 1986; 314:1140–1145
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Lung Transplantation
2.de Perrot M, Chaparro C, McRae K, et al. Twenty-year experience of lung
transplantation at a single center: influence of recipient diagnosis on long-term
survival. J Thorac Cardiovasc Surg 2004; 127:1493–1501
3.Trulock EP, Christie JD, Edwards LB, et al. Registry of the International Society for Heart and Lung Transplantation: twenty-fourth official adult lung and
heart-lung transplantation report—2007. J Heart Lung Transplant 2007;
26:782–795
4.Alvarez A, Algar J, Santos F, et al. Airway complications after lung transplantation: a review of 151 anastomoses. Eur J Cardiothorac Surg 2001;
19:381–387
5.Lima O, Goldberg M, Peters WJ, Ayabe H, Townsend E, Cooper JD. Bronchial
omentopexy in canine lung transplantation. J Thorac Cardiovasc Surg 1982;
83:418–421
6.Kshettry VR, Kroshus TJ, Hertz MI, Hunter DW, Shumway SJ, Bolman RM
3rd. Early and late airway complications: incidence and management. Ann
Thorac Surg 1997; 63:1576–1583
7.McAdams HP, Murray JG, Erasmus JJ, Goodman PC, Tapson VF, Davis RD.
Telescoping bronchial anastomosis for unilateral or bilateral sequential lung
transplantation: CT appearance. Radiology 1997; 203:202–206
8.Erasmus JJ, McAdams HP, Tapson VF, Murray JG, Davis RD. Radiologic issues in lung transplantation for end-stage pulmonary disease. AJR 1997;
169:69–78
9.Van De Wauwer C, Van Raemdonck D, Verleden GM, et al. Risk factors for
airway complications within the first year after lung transplantation. Eur J Cardiothorac Surg 2007; 31:703–710
10.Date H, Trulock EP, Arcidi JM, Sundaresan S, Cooper JD, Patterson GA. Improved airway healing after lung transplantation: an analysis of 348 bronchial
anastomoses. J Thorac Cardiovasc Surg 1995; 110:1424–1433
11.Murray JG, McAdams HP, Erasmus JJ, et al. Complications of lung transplantation: radiologic findings. AJR 1996; 166:1405–1411
12.Collins J, Kuhlman JE, Love RB. Acute, life-threatening complications of lung
transplantation. RadioGraphics 1998; 18:21–43
13.Herman SJ, Weisbrod GL, Weisbrod L, Patterson GA, Maurer JR. Chest radiographic findings after bilateral lung transplantation. AJR 1989; 153:1181–1185
14.Semenkovich JW, Glazer HS, Anderson DC, Arcidi JM Jr, Cooper JD, Patterson GA. Bronchial dehiscence in lung transplantation: CT evaluation. Radiology 1995; 194:205–208
15.Quint LE, Whyte RI, Kazerooni EA, et al. Stenosis of the central airways:
evaluation by using helical CT with multiplanar reconstructions. Radiology
1995; 194:871–877
16.Clark SC, Levine AJ, Hasan A, Hilton CJ, Forty J, Dark JH. Vascular complications of lung transplantation. Ann Thorac Surg 1996; 61:1079–1082
17.Frost AE. Donor criteria and evaluation. Clin Chest Med 1997; 18:231–237
18.Ward S, Müller NL. Pulmonary complications following lung transplantation.
Clin Radiol 2000; 55:332–339
19.Collins J, Love RB. Pulmonary torsion: complication of lung transplantation.
AJR:192, March 2009
Clin Pulm Med 1996; 3:297–298
20.Ferrer J, Roldan J, Roman A, et al. Acute and chronic pleural complications in
lung transplantation. J Heart Lung Transplant 2003; 22:1217–1225
21.Herridge MS, de Hoyos AL, Chaparro C, Winton TL, Kesten S, Maurer JR.
Pleural complications in lung transplant recipients. J Thorac Cardiovasc Surg
1995; 110:22–26
22.Kundu S, Herman SJ, Winton TL. Reperfusion edema after lung transplantation: radiographic manifestations. Radiology 1998; 206:75–80
23.Garg K, Zamora MR, Tuder R, et al. Lung transplantation: indications, donor
and recipient selection, and imaging of complications. RadioGraphics 1996;
16:355–367
24.Gotway MB, Dawn SK, Sellami D, et al. Acute rejection following lung transplantation: limitations in accuracy of thin-section CT for diagnosis. Radiology
2001; 221:207–212
25.Bergin CJ, Castellino RA, Blank N, Berry GJ, Sibley RK, Starnes VA. Acute
lung rejection after heart–lung transplantation: correlation of findings on chest
radiographs with lung biopsy results. AJR 1990; 155:23–27
26.Loubeyre P, Revel D, Delignette A, Loire R, Mornex JF. High-resolution computed tomographic findings associated with histologically diagnosed acute
lung rejection in heart–lung transplant recipients. Chest 1995; 107:132–138
27.Collins J, Müller NL, Kazerooni EA, Paciocco G. CT findings of pneumonia
after lung transplantation. AJR 2000; 175:811–818
28.Reams BD, McAdams HP, Howell DN, Stelle MP, Davis RD, Palmer SM.
Posttransplant lymphoproliferative disorder: incidence, presentation and response to treatment in lung transplant recipients. Chest 2003; 124:1242–1249
29.Nicod LP. Mechanisms of airway obliteration after lung transplantation. Proc
Am Thorac Soc 2006; 3:444–449
30.Chamberlain D, Maurer J, Chaparro C, Idolor L. Evaluation of transbronchial
lung biopsy specimens in the diagnosis of bronchiolitis obliterans after lung
transplantation. J Heart Lung Transplant 1994; 13:963–971
31.Morrish WF, Herman SJ, Weisbrod GL, Chamberlain DW. Bronchiolitis obliterans after lung transplantation: findings at chest radiography and high resolution CT. The Toronto Lung Transplant Group. Radiology 1991; 179:487–490
32.Konen E, Gutierrez C, Chaparro C, et al. Bronchiolitis obliterans syndrome in
lung transplant recipients: can thin-section CT findings predict disease before
its clinical appearance? Radiology 2004; 231:467–473
33.de Perrot M, Chernenko S, Waddell TK, et al. Role of lung transplantation in
the treatment of bronchogenic carcinomas for patients with end-stage pulmonary disease. J Clin Oncol 2004; 22:4351–4356
34.Collins J, Hartman MJ, Warner TF, et al. Frequency and CT findings of recurrent disease after lung transplantation. Radiology 2001; 219:503–509
35.Konen E, Weisbrod GL, Pakhale S, et al. Fibrosis of the upper lobes: a newly
identified late-onset complication after lung transplantation? AJR 2003;
181:1539–1543
36.Kazerooni EA, Cascade PN, Gross BH. Transplanted lungs: nodules following
transbronchial biopsy. Radiology 1995; 194:209–212
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AJR Integrative Imaging
1.5 CME
1.0 SAM
LIFELONG LEARNING
FOR RADIOLOGY
Imaging of Lung Transplantation:
Self-Assessment Module
Yuen Li Ng1, 2, Narinder Paul3, Demetris Patsios3, Anna Walsham4, Tae-Bong Chung3, Shaf Keshavjee5, Gordon Weisbrod3
ABSTRACT
Objective
The educational objectives of this continuing medical
education activity are for the reader to exercise, self-assess,
and improve skills in diagnostic radiology with regard to
imaging of lung transplantation and to improve familiarity
with the complications of lung transplantation.
Conclusion
The articles in this activity review the imaging and complications of lung transplantation and discuss the role of
imaging in the assessment of complications from lung
transplantation.
INTRODUCTION
This self-assessment module on imaging of lung transplantation has an educational component and a self-assessment
component. The educational component consists of one required article that the participant should read. The self-assessment component consists of 10 multiple-choice questions
with solutions. All of these materials are available on the
ARRS Website (www.arrs.org). To claim CME and SAM
credit, each participant must first order the CME activity,
then enter his or her responses to the questions online.
EDUCATIONAL OBJECTIVES
By completing this educational activity, the participant will:
A.Exercise, self-assess, and improve his or her understanding of the imaging of lung transplantation.
B.Exercise, self-assess, and improve his or her understanding of the complications of lung transplantation.
REQUIRED READING
1.Ng YL, Paul N, Patsios D, et al. Imaging of lung transplantation: review. AJR 2009; 192[suppl]:
INSTRUCTIONS
1.Complete the educational and self-assessment components included in this issue.
2.Visit www.arrs.org and log in.
3.Select Publications/Journals/SAM Articles from the lefthand menu bar.
4.Order the online SAM as directed. (The SAM must be
ordered to be accessed even though the activity is free to
ARRS members.)
5.The SAM can be accessed at www.arrs.org/My Education/My Online Products, but you must be logged in to
access this personalized page.
6.Answer the questions online to obtain SAM credit.
Keywords: lung transplantation
DOI:10.2214/AJR.07.7130
Received November 29, 2007; accepted without revision February 19, 2008.
CT Unit, Jubilee Wing, Department of Clinical Radiology, Leeds General Infirmary, Leeds LS1 3EX, West Yorkshire, United Kingdom.
1
Present address: Department of Diagnostic Radiology, Singapore General Hospital, Outram Rd., Singapore 169608. Address correspondence to Y. L. Ng ([email protected]).
2
Joint Department of Medical Imaging, Thoracic Division, University Health Network and Mount Sinai Hospital, Toronto General Hospital, Toronto, ON, Canada.
3
Department of Clinical Radiology, Hope Hospital, Manchester, United Kingdom.
4
Division of Thoracic Surgery and Toronto Lung Transplant Program, Toronto General Hospital, Toronto, ON, Canada.
5
AJR 2009;192:SXX–SXX 0361–803X/09/1923–SX © American Roentgen Ray Society
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AJR:192, March 2009
Ng et al.
QUESTION 1
Concerning early complications of lung trans­
plantation, which of the following is TRUE?
A. Bronchial dehiscence is usually diagnosed on chest
radiography.
B. Reimplantation response is a form of noncardiogenic pulmonary edema and occurs in more than
95% of lung transplantation patients.
C. CT features of acute rejection, such as ground-glass
opacities, interlobular septal thickening, nodules,
and consolidation, are accurate in the diagnosis and
assessment of severity of acute rejection.
D. Acute rejection responds poorly to corticosteroids.
QUESTION 2
Concerning late complications of lung trans­
plantation, which of the following statements is
FALSE?
A. Obliterative bronchiolitis usually develops 6–18
months after transplantation and is associated with
previous multiple episodes of acute rejection and
cytomegalovirus (CMV) pneumonia.
B. Obliterative bronchiolitis is a histologic diagnosis
affecting the small airways and is reliably excluded
by negative transbronchial biopsy.
C. Upper lobe fibrosis is hypothesized to be a rare
manifestation of chronic rejection in lung trans­
plantation patients.
D. Posttransplantation lymphoproliferative disorder
occurs more commonly in patients with lung
transplants than in patients with other solid organ
transplants.
QUESTION 3
Which of the following statements regarding
infection after lung transplantation is FALSE?
A. Bacterial infections usually occur in the first month
after transplantation.
B. Most common bacterial infections are due to
gram-negative bacilli such as Klebsiella organisms
and Pseudomonas aeruginosa.
C. Aspergillosis is more prevalent in lung transplantation patients than in other immunocompromised
patients.
D. Pulmonary nodules on CT with a surrounding halo
of ground glass are specific for invasive aspergillosis
in lung transplantation patients.
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QUESTION 4
Which of the following statements is TRUE
regarding CMV infection after lung trans­
plantation?
A. CMV infection is the most common cause of
pneumonia.
B. CMV infection is the most common opportunistic
infection.
C. Primary CMV infection occurs in seropositive
recipients who receive a graft from a seropositive
donor.
D. Secondary CMV infection develops from re­
activation of a latent virus or from infection with
a different CMV strain and is usually more serious
than primary infection.
E. Posttransplantation lymphoproliferative disorder
is thought to be secondary to B-lymphocyte pro­
liferation in response to CMV infection.
QUESTION 5
Which of the following features is LEAST
commonly seen on CT in obliterative
bronchiolitis after lung transplantation?
A.
B.
C.
D.
E.
Bronchial wall thickening and dilatation.
Nodules.
Pleural effusion.
Mosaic attenuation.
Air trapping.
QUESTION 6
Concerning pulmonary parenchymal
complications after lung transplantation,
which of the following is LEAST LIKELY to
manifest as pulmonary nodules?
A.
B.
C.
D.
E.
Invasive pulmonary aspergillosis.
Reimplantation response.
Bronchial carcinoma.
Hematoma after transbronchial biopsy.
Posttransplantation lymphoproliferative disorder.
AJR:192, March 2009
Lung Transplantation
QUESTION 7
Which of the following statements concerning
patients after lung transplantation is FALSE?
A. Acute rejection is the most common cause of
mortality during the first 6 months after lung
transplantation.
B. Obliterative bronchiolitis is the most common
cause of mortality in lung transplantation patients
beyond 6 months after transplantation.
C. Empyema is the only pleural complication associated
with increased mortality and should be excluded
in a new or enlarging pleural effusion after lung
transplantation.
D. The overall reported 5-year survival rate for lung
transplantation patients is approximately 50%.
QUESTION 9
Which of the following statements is TRUE
regarding pleural complications after lung
transplantation?
A. Pneumothorax is a rare complication after lung
transplantation.
B. Persistent or enlarging pneumothorax in the presence
of thoracostomy drains should prompt further
investigations to elucidate the cause of the air leak.
C. Pleural effusions seldom occur in patients after
lung transplantation.
D. Pleural effusions are usually self-limiting and
resolve within 2 months.
QUESTION 8
Which of the following statements concern­
ing airway complications after lung trans­
plantation is FALSE?
A. Airway anastomotic complications was one of the
major obstacles to success in the early years of
lung transplantation but is now rarely encountered
(< 1% of lung transplantation patients).
B. Bronchial dehiscence is the most common
airway complication in the early postoperative
period, typically occurring 2–4 weeks after
transplantation.
C. CT occasionally shows a focal bronchial wall defect
that is pathognomonic of bronchial dehiscence.
D. Bronchial stricture formation occurs later in the
postoperative period, an average of 3 months after
transplantation.
Solution to Question 1
Option B is the best response. Reimplantation response
occurs in more than 95% of lung transplantation patients
[1]. The pathogenesis is probably multifactorial: increased
vascular permeability due to ischemia and subsequent re­
perfusion, lymphatic interruption, lung denervation, decreased surfactant production, and surgical trauma [2]. Option A is not the best response. Airway complications are
usually diagnosed at bronchoscopy. Chest radiographs are
unreliable in the diagnosis of airway complications [3]. CT
is useful in the diagnosis of bronchial dehiscence, showing
extraluminal gas and focal bronchial wall defects [4]. CT
can also show bronchial stenoses and is particularly valuable in assessing the length of stenoses to plan for stent in-
AJR:192, March 2009
QUESTION 10
The figure above shows a single axial CT image
of a 53-year-­old patient on day 2 after bilateral
lung transplantation. What is the MOST
LIKELY diagnosis?
A.
B.
C.
D.
Acute rejection.
Bacterial infection.
Fungal infection.
Reimplantation response.
sertion and assessing position of stents [5]. Option C is not
the best response. CT features of acute rejection are nonspecific (i.e., ground-glass opacities, interlobular septal
thickening, nodules, and consolidation), and CT is of limited accuracy in the diagnosis or grading of severity of acute
rejection [6]. Transbronchial biopsy is often performed to
confirm the diagnosis and to exclude infection [7]. Pathology showed perivascular lymphocytic infiltrates, which may
progress to extend into the alveolar septa and alveoli. Acute
rejection is histologically graded on a scale of 0–4 on the
basis of the severity of the reaction. Option D is not the
best response. The most useful diagnostic feature of acute
rejection is the dramatic clinical and radiographic response
to corticosteroids and increased immunosuppression [7, 8].
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Ng et al.
Solution to Question 2
Option B, which is not true, is the best response. Obliterative bronchiolitis is a histologic diagnosis affecting the small
airways in a patchy distribution; transbronchial biopsy
may not be diagnostic, particularly in the early stages [9].
Therefore, this disorder is frequently diagnosed clinically,
using the term “bronchiolitis obliterans syndrome,” on the
basis of an otherwise unexplained decline in lung function
[10]. Option A is a true statement and therefore is not the
best response [7]. Option C is not the best response. Upper
lobe fibrosis is uncommon, reported to occur 18–72 months
after lung transplantation [11]. The exact pathogenesis is
unknown but is hypothesized to be a rare manifestation of
chronic rejection. Pathology may show nonspecific inflammation and fibrosis. Option D is not the best response. Posttransplantation lymphoproliferative disorder (PTLD) is a
spectrum of diseases that vary from a histologically benign
polyclonal lymphoid proliferation to aggressive high-grade
lymphoma [12]. The incidence is approximately 5% (range,
1.8–20%), which is more common than in patients with
other solid organ transplants [12, 13]. In contrast to other
solid organ transplantation patients, PTLD in lung transplantation patients usually manifests as pulmonary nodules
or masses [12], and extrapulmonary involvement is less
common (e.g., hilar or mediastinal adenopathy, thymic enlargement, pleural effusions, and pericardial masses) [13].
Solution to Question 3
Option D is the best response. Pulmonary nodules with a surrounding halo of ground glass (i.e., the CT halo sign) were originally described in patients with angioinvasive pulmonary
aspergillosis [14]. Since then, however, this appearance has been
recognized in other infections (e.g., candidiasis, cytomegalovirus [CMV]), neoplastic disorders (e.g., PTLD, bronchioloalveolar carcinoma), and inflammatory conditions (e.g., hematoma after transbronchial biopsy) [15]. Options A and B are
not the best responses. Bacterial infections account for at least
50% of all infections [13]. The incidence is highest in the first
month, but the possibility of bacterial infection remains
throughout the patient’s life. Most common causative organisms are gram-negative bacilli such as Klebsiella organisms,
Pseudomonas aeruginosa, and Enterobacter cloacae. Gram-positive organisms such as Staphylococcus aureus are also observed
[7, 13]. Option C is not the best response. Aspergillosis is more
prevalent in lung transplantation patients than in other
immunocompromised patients. Locally invasive or disseminated aspergillus infection accounts for 2–33% of infections after
lung transplantation and 4–7% of all lung transplantation
deaths [16]. Aspergillus can cause indolent pneumonia or fulminant angioinvasive infection with systemic dissemination.
Solution to Question 4
Option B is the best response. CMV is the most common
opportunistic infection after lung transplantation [16]. Op-
S4
tion A is not the best response. CMV is the second most
common cause of pneumonia (after bacterial infection) in
lung transplantation patients [16]. Options C and D are not
the best responses. Primary infection occurs in CMV-seronegative recipients who receive a graft from a seropositive
donor. Infection develops in more than 90% and is serious
in 50–60% of cases [16]. Thus, CMV matching between donor and recipient is performed whenever possible. Secondary infection develops from reactivation of a latent virus
after immunosuppression or from infection with a different
CMV strain. It is usually less serious than a primary infection [7]. Option E is not the best response. PTLD is thought
to be secondary to B-lymphocyte proliferation in response
to Epstein-Barr virus (EBV) infection [13]. It is more commonly seen in EBV-seronegative recipients who receive an
EBV-seropositive donor lung.
Solution to Question 5
Option C is the best response. Pleural effusion is the least
likely of the listed findings to be seen in obliterative bronchiolitis. CT findings of obliterative bronchiolitis include bronchial
dilatation, bronchial wall thickening, nodular and linear opacities, air trapping, mosaic attenuation, and peribronchovascular infiltrates that are most marked in the lower lobes [17]. Air
trapping is the most frequent feature. However, its presence
may be intermittent in patients with obliterative bronchiolitis
and is of limited sensitivity for the early diagnosis of obliterative bronchiolitis [18]. Options A, B, D, and E, which are likely
findings, are not the best responses.
Solution to Question 6
Option B is the best response. Reimplantation response (or
reperfusion edema) is a form of noncardiogenic pulmonary
edema. Chest radiography and CT typically show bilateral
perihilar and basal air-space opacification [1]. Options A, C,
D, and E are not the best responses. Pulmonary nodules after
lung transplantation are largely due to infection, PTLD, and
malignancy [19]. Chest radiography is a useful screening tool,
but CT is more sensitive in detecting and characterizing nodules. Bronchoscopy with bronchioalveolar lavage and transbronchial biopsy, as well as CT-guided and video-assisted
thoracic surgery biopsy, should also be considered. Solid and
cavitary nodules with surrounding ground-glass attenuation
may be identified on CT up to 1 month after transbronchial
biopsy. The ground-glass attenuation represents hemorrhage
secondary to biopsy. The temporal relationship to the biopsy
and the location at known biopsy sites should prevent confusion with infection [20].
Solution to Question 7
Option A is the best response. Infection is the most common cause of mortality during the first 6 months after lung
transplantation [21]. Patients have an increased susceptibility to infection because of immunosuppression, lung
AJR:192, March 2009
Lung Transplantation
denervation with loss of the cough reflex, impaired mucociliary function, and lymphatic drainage [7, 16]. Option B is
not the best response. Chronic rejection or obliterative bronchiolitis is the most common cause of mortality more than
6 months after lung transplantation [21]. Option C is not
best response. Pleural effusions occur in almost all patients
but are usually self-limiting and resolve within 2 weeks [2,
22]. Persistent or new effusions suggest a complication such
as empyema. A single communicating pleural space commonly develops after bilateral lung and heart–lung transplantations. Therefore, empyema may affect both hemithoraces with potentially disastrous consequences [7, 22–24].
Option D is not the best response as it is a true statement.
The reported survival rates from January 1994 to June 2005
were 87% at 3 months, 78% at 1 year, 62% at 3 years, 50%
at 5 years, and 26% at 10 years.
Solution to Question 8
Option A, which is not true, is the best response. Although
the incidence of airway complications has decreased with
improved surgical and donated-organ preservation techniques, immunosuppression, and posttransplantation surveillance [7, 25, 26], airway complications still cause significant morbidity and have been estimated to occur in
approximately 5–15% of lung transplantation patients
[24–28]. Options B and C are not the best responses. Bronchial dehiscence is the most common airway complication
in the early postoperative period, affecting 2–3% of cases
[2, 21, 27]. CT typically shows the presence of extraluminal
gas and, occasionally, the focal bronchial wall defect that is
pathognomonic of this condition [4]. Indirect signs of bronchial dehiscence include the presence of a new or persistent
air leak, pneumothorax, and pneumomediastinum. Option
D is not the best response because it is a true statement.
Bronchial stricture formation is seen in approximately 10%
of patients [26–28].
Solution to Question 9
Option B is the best response. Pneumothorax usually resolves with the insertion of thoracostomy drains [7, 23].
New, persistent, or enlarging pneumothoraces should
prompt further investigation to elucidate the cause of the
air leak. Option A is not the best response. Pneumothorax
is the most common pleural complication after lung transplantation [7, 23]. Bilateral lung and heart–lung transplantations frequently result in a single communicating pleural
space. Therefore, pneumothoraces are often bilateral [7].
Options C and D are not the best responses. Pleural effusions develop in almost all transplantation patients because
of increased capillary permeability and impaired lymphatic
clearance of the transplanted lung [2, 22]. They are usually
self-limiting and resolve within 2 weeks. Persistent or delayed effusions suggest complicated effusions such as empyema, organized hematoma, rejection, and PTLD.
AJR:192, March 2009
Solution to Question 10
Option D is the best response. The CT image shows bilateral ground-glass opacities, air-space consolidation, and
interlobular septal thickening. At day 2 after lung transplantation, reimplantation response is the most likely diagnosis. Reimplantation response frequently begins by day 1,
is always present by day 3, peaks by day 4 or 5, and resolves
by day 10 [7, 13]. In clinical practice, it is usually diagnosed
after exclusion of left ventricular failure, fluid overload,
transplant rejection, and infection [1, 8]. Options A, B, and
C are not the best responses. The radiologic features of
acute rejection and pneumonia may be similar to those of
reimplantation response [16, 29]. However, acute rejection
and pneumonia tend to occur later than reimplantation response after lung transplantation. Acute rejection usually
occurs within the first 3 weeks, typically between days 5
and 10 [7]. Bacterial pneumonia tends to predominate in
the first month after lung transplantation, and fungal pneumonia usually occurs between 10 and 60 days after transplantation [16].
References
1. Kundu S, Herman SJ, Winton TL. Reperfusion edema after lung transplantation: radiographic manifestations. Radiology 1998; 206:75–80
2. Collins J, Kuhlman JE, Love RB. Acute, life-threatening complications of
lung transplantation. RadioGraphics 1998; 18:21–43
3. Herman SJ, Weisbrod GL, Weisbrod L, Patterson GA, Maurer JR. Chest radiographic findings after bilateral lung transplantation. AJR 1989; 153:1181–1185
4. Semenkovich JW, Glazer HS, Anderson DC, Arcidi JM Jr, Cooper JD, Patterson GA. Bronchial dehiscence in lung transplantation: CT evaluation. Radiology 1995; 194:205–208
5. Quint LE, Whyte RI, Kazerooni EA, et al. Stenosis of the central airways:
evaluation by using helical CT with multiplanar reconstructions. Radiology
1995; 194:871–877
6. Gotway MB, Dawn SK, Sellami D, et al. Acute rejection following lung transplantation: limitations in accuracy of thin-section CT for diagnosis. Radiology
2001; 221:207–212
7. Erasmus JJ, McAdams HP, Tapson VF, Murray JG, Davis RD. Radiologic issues in lung transplantation for end-stage pulmonary disease. AJR 1997;
169:69–78
8. Garg K, Zamora MR, Tuder R, et al. Lung transplantation: indications, donor
and recipient selection, and imaging of complications. RadioGraphics 1996;
16:355–367
9. Chamberlain D, Maurer J, Chaparro C, Idolor L. Evaluation of transbronchial
lung biopsy specimens in the diagnosis of bronchiolitis obliterans after lung
transplantation. J Heart Lung Transplant 1994; 13:963–971
10. Nicod LP. Mechanisms of airway obliteration after lung transplantation. Proc
Am Thorac Soc 2006; 3:444–449
11. Konen E, Weisbrod GL, Pakhale S, et al. Fibrosis of the upper lobes: a newly
identified late-onset complication after lung transplantation? AJR 2003;
181:1539–1543
12. Reams BD, McAdams HP, Howell DN, Stelle MP, Davis RD, Palmer SM.
Posttransplant lymphoproliferative disorder: incidence, presentation and response to treatment in lung transplant recipients. Chest 2003; 124:1242–1249
13. Murray JG, McAdams HP, Erasmus JJ, et al. Complications of lung transplantation: radiologic findings. AJR 1996; 166:1405–1411
14. Kuhlman JE, Fishman EK, Siegelman SS. Invasive pulmonary aspergillosis in
acute leukemia: characteristic findings on CT, the CT halo sign, and the role of
CT in early diagnosis. Radiology 1985; 157:611–614
15. Lee YR, Choi YW, Lee KJ, Jeon SC, Park CK, Heo JN. CT halo sign: the
S5
Ng et al.
spectrum of pulmonary diseases. Br J Radiol 2005; 78:862–865
16. Collins J, Muller NL, Kazerooni EA, Paciocco G. CT findings of pneumonia
after lung transplantation. AJR 2000; 175:811–818
17. Morrish WF, Herman SJ, Weisbrod GL, Chamberlain DW. Bronchiolitis obliterans after lung transplantation: findings at chest radiography and high resolution CT. The Toronto Lung Transplant Group. Radiology 1991; 179:487–490
18. Konen E, Gutierrez C, Chaparro C, et al. Bronchiolitis obliterans syndrome in
lung transplant recipients: can thin-section CT findings predict disease before
its clinical appearance? Radiology 2004; 231:467–473
19. Lee P, Minai OA, Mehta AC, DeCamp MM, Murthy S. Pulmonary nodules in
lung transplant recipients. Chest 2004; 125:165–172
20. Kazerooni EA, Cascade PN, Gross BH. Transplanted lungs: nodules following
transbronchial biopsy. Radiology 1995; 194:209–212
21. de Perrot M, Chaparro C, McRae K, et al. Twenty-year experience of lung
transplantation at a single center: influence of recipient diagnosis on long-term
survival. J Thorac Cardiovasc Surg 2004; 127:1493–1501
22. Ferrer J, Roldan J, Roman A, et al. Acute and chronic pleural complications in
lung transplantation. J Heart Lung Transplant 2003; 22:1217–1225
23. Herridge MS, de Hoyos AL, Chaparro C, Winton TL, Kesten S, Maurer JR.
S6
Pleural complications in lung transplant recipients. J Thorac Cardiovasc Surg
1995; 110:22–26
24. Trulock EP, Christie JD, Edwards LB, et al. Registry of the International Society
for Heart and Lung Transplantation: twenty-fourth official adult lung and heart–
lung transplantation report—2007. J Heart Lung Transplant 2007; 26:782–795
25. Alvarez A, Algar J, Santos F, et al. Airway complications after lung transplantation: a review of 151 anastomoses. Eur J Cardiothorac Surg 2001; 19:381–387
26. Date H, Trulock EP, Arcidi JM, Sundaresan S, Cooper JD, Patterson GA. Improved airway healing after lung transplantation: an analysis of 348 bronchial
anastomoses. J Thorac Cardiovasc Surg 1995; 110:1424–1433
27. Kshettry VR, Kroshus TJ, Hertz MI, Hunter DW, Shumway SJ, Bolman RM
3rd. Early and late airway complications: incidence and management. Ann
Thorac Surg 1997; 63:1576–1583
28. Van De Wauwer C, Van Raemdonck D, Verleden GM, et al. Risk factors for
airway complications within the first year after lung transplantation. Eur J
Cardiothorac Surg 2007; 31:703–710
29.Bergin CJ, Castellino RA, Blank N, Berry GJ, Sibley RK, Starnes VA. Acute
lung rejection after heart–lung transplantation: correlation of findings on chest
radiographs with lung biopsy results. AJR 1990; 155:23–27
AJR:192, March 2009
AJR Integrative Imaging
LIFELONG LEARNING
FOR RADIOLOGY
CT Virtual Endoscopy in the Evaluation of
Large Airway Disease: Review
Bradley P. Thomas1, Megan K. Strother, Edwin F. Donnelly, John A. Worrell
Objective
The purpose of this article is to illustrate the usefulness
and limitations of CT virtual endoscopy in the evaluation
of large airway disease.
Conclusion
CT virtual endoscopy is a postprocessing tool that is easy
to perform and that can aid in depicting disorders of the
large airways without additional radiation or cost other
than added time in postprocessing. The benefits of this
technique include noninvasive diagnostic surveillance and
preoperative planning.
Introduction
CT virtual endoscopy has been used to evaluate pathologic
processes of the nasopharynx, larynx, and tracheobronchial
tree [1–5]. Findings are generally made first on the CT source
images. The stunning CT virtual endoscopic images subsequently generated allow pulmonologists and otolaryngologists the anatomic perspectives of the large airway that they
are clinically accustomed to viewing. Effective clinical consultation requires the practicing radiologist to be familiar
with the technique of generating these images, as well as the
anatomy and pathologic conditions shown.
CT Virtual Endoscopy Technique
Unlike virtual colonoscopy, no preprocedural patient
preparation is needed to evaluate the large airways. CT virtual endoscopy applications are performed retrospectively
to aid in the depiction of data detected on routine image
interpretation that may be useful to referring physicians.
The high contrast of an air-filled lumen renders 3D and 4D
imaging that closely resembles the conventional endoscopic
correlate. All CT virtual endoscopy review was performed
after approval of the institutional review board, using diagnostic neck and chest CT scans at our institution. All CT
examinations were performed on either the 64-MDCT Brilliance CT scanner or the 16-MDCT MX8000IDT CT scan-
ner (both Philips Healthcare) using routine departmental
protocols (Table 1). With the 64-MDCT scanner, isotropic
data are acquired routinely on all chest and neck CT scans.
Because dose efficiency is quite high with the 64-MDCT
scanner, there is no significant radiation cost to the patient
for isotropy. Some additional radiation dose occurs when
acquiring isotropic data with the 16-MDCT scanner. At our
institution, isotropic data are routinely acquired on neck
CT examinations to allow high-quality multiplanar reformations. Although no preprocedure preparation is required,
imaging of the proximal airways can be optimized for luminal distention with maximum aeration using either the
modified Valsalva or the phonation technique [6].
Postprocessing was performed with the virtual endoscopy
application. Using CT virtual endoscopy application software, preset tissue algorithms (e.g., trachea) change the color
scheme and set thresholds that define the tissue–air interface.
Once the data are loaded into the endoscopy application, the
cursor can be moved into the airway lumen, and the observer’s view is directed as desired using the swivel tool to provide
the best images of the desired region. It is helpful to orient
the image to correspond with a conventional endoscopic view.
For example, nasal endoscopy is performed in a face-to-face
doctor–patient orientation. This is in contrast to bronchoscopy, in which the bronchoscopist is usually positioned behind the patient, having the same right–left orientation. Labeling the CT virtual endoscopic images may be necessary for
clarification. Postprocessing requires approximately 10 additional minutes per examination.
Virtual Nasopharyngoscopy and
Laryngoscopy
Choanal Atresia
CT virtual endoscopy of the normal nasopharynx from a
posterior viewpoint provides a look at the eustachian tube
openings in reference to the choanae and nasopharyngeal
walls, an area difficult to appreciate with conventional CT
Keywords: airway disease, choanal atresia, CT, CT virtual endoscopy, infiltrative airway disease, transbronchial biopsy
DOI:10.2214/AJR.07.7077
Received February 5, 2008; accepted after revision June 2, 2008.
1
All authors: Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, CCC-1121, MCN, 1161 21st Ave. S, Nashville, TN 37232-2675. Address
correspondence to B. P. Thomas ([email protected]).
AJR 2009;192:SXX–SXX 0361–803X/09/1923–SX © American Roentgen Ray Society
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AJR:192, March 2009
Thomas et al.
A
B
Fig. 1—4-year-old girl with bony right-sided choanal atresia.
A, Normal posterior nasopharynx CT virtual endoscopic view with roof of naso­
pharynx above and soft palate (sp) below showing choanae (curved arrow),
turbinates (t), and eustachian tube opening (straight arrow).
B and C, CT virtual endoscopy (B) and axial CT (C) images show bony obstruction (arrow, B) and characteristically thickened vomer (asterisk, B). sp = soft
palate, t = turbinates.
C
TABLE 1: Protocols Used in CT Virtual Endoscopy Examples
Scanner
kVp
mAs
Collimation (mm)
Pitch
Rotation Time (s)
Matrix
Field of View (mm)
Neck
120
300
64 × 0.625
0.891
0.75
512
250
Chest
120
250
32 × 1.25
0.906
0.75
512
400
Neck
120
300
16 × 0.75
0.9
0.75
512
250
Chest
140
150
16 × 0.75
0.9
0.75
512
400
64-MDCT, Brilliance
16-MDCT, MX8000IDT
Note—Both scanners are by Philips Healthcare.
[1] (Fig. 1A). This is compared to a 4-year-old girl in whom
the right posterior nasal cavity is blocked, consistent with
choanal atresia (Figs. 1B and 1C). Note the abnormally
thickened vomer in choanal atresia, a finding important in
diagnosis and preoperative planning [7].
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Epiglottitis
Compare the normal epiglottis (Fig. 2A) with that of an
immunocompromised patient who presented to the emergency department with a markedly thickened epiglottis
and symptoms consistent with acute epiglottitis (Figs. 2B
AJR:192, March 2009
CT Virtual Endoscopy of Airway Disease
A
B
Fig. 2—25-year-old man with acute epiglottitis.
A, Normal virtual laryngoscopy shows epiglottis (thick arrow), vallecula (v), pyriform sinus (ps), aryepiglottic fold (long thin arrow), arytenoid prominence
(short thin arrow), and glottis (asterisk).
B and C, Virtual laryngoscopy image (B) and contrast-enhanced CT image (C)
show severely edematous epiglottis (thick arrow) and arytenoids (thin arrows).
C
and 2C). CT virtual endoscopy can provide a familiar view
to the endoscopist for planning subsequent intervention,
which is usually required when the airway is compromised
by more than 50% [8].
Vocal Cord Lesions
When imaging the glottis, evaluation of submucosal extent
of disease is the mainstay of the CT examination. However,
CT virtual endoscopy can direct biopsy planning of cord lesions. With CT virtual endoscopy, the 3D location of polypoid
lesions is easier to appreciate. True polyps most often occur
along the anterior third of the vocal cord, whereas polypoid
corditis, a form of Reinke’s edema, is usually more diffuse.
AJR:192, March 2009
Reinke’s edema is a chronic laryngeal disease found almost
exclusively in smokers that is difficult to diagnose with imaging alone. Imaging of a 46-year-old woman with a long history of smoking and hoarseness who presented with increasingly labored breathing is shown (Fig. 3). CT virtual endoscopy
depicts diffuse vocal cord edema with a superimposed polypoid area of swelling (Fig. 3A). Both true polyps and Reinke’s
edema can cause acoustic dysfunction, but the latter is much
more likely to cause airway compromise [9]. When glottic obstruction is present, we have found it difficult to delineate laryngeal structures with CT virtual endoscopy (Figs. 2B and
3A). However, laryngeal airway distension techniques may
help when evaluating known laryngeal disease [6].
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Thomas et al.
A
B
Fig. 3—46-year-old woman with Reinke’s edema.
A, Virtual laryngoscopy image shows edematous true vocal cords (asterisks)
and polypoid mass emanating from mid and posterior left true cord (arrow).
B, Conventional endoscopic view in same patient, now undergoing intubation,
shows lobulated lesion.
C, Axial contrast-enhanced CT image shows polypoid mass (arrow) and lack of
deep invasion.
C
Virtual Tracheoscopy
Radiologists should be able to recognize the normal tracheal architecture and anatomic variants. In particular,
normal structures such as the transverse aorta can indent
the large airways and need not be confused with extrinsic
lesions when viewed endoscopically. Note how CT virtual
endoscopy nicely shows the posterolateral location of a tracheal bronchus from an endoluminal perspective (Fig. 4).
CT virtual endoscopy of the trachea is a useful postprocessing tool because views of disorders can closely resemble
those of conventional endoscopy, making this a much appreciated extra step from the endoscopist’s perspective.
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Non–Small Cell Lung Cancer
Biopsy planning in the workup of a lung mass hinges on
lesion location and size. A decision must be made whether to
perform percutaneous, open, or transbronchial biopsy. Virtual tracheobronchoscopy can guide this decision-making
algorithm by assessing extrinsic mass effect. If a peribronchial lesion is exerting mass effect, transbronchial biopsy
may be performed successfully. In this example, we studied a
64-year-old man with vocal cord paralysis due to mediastinal
invasion of non–small cell lung cancer. In conjunction with
the axial CT appearance, virtual tracheoscopy can further
evaluate true vocal cord paralysis (Figs. 5A and 5B) second-
AJR:192, March 2009
CT Virtual Endoscopy of Airway Disease
ary to recurrent laryngeal nerve involvement by a stage T4
mediastinal mass (Figs. 5C and 5D). Note the obscuring of
the right bronchial orifice as compared with a more normalcaliber distal trachea (Fig. 4). Virtual tracheobronchoscopy
has promise for transluminal biopsy planning [5].
Postintubation Tracheal Stenosis
Endotracheal intubation is the most common cause of acquired tracheal stenosis, which may follow prolonged tracheal balloon inflation. With the implementation of lowpressure cuffs, the incidence has been reduced to less than
1% [10]. Presented here is one such example in a 14-year-old
boy who sustained burns and underwent intubation for less
than a week, 1 month before this CT examination (Fig. 6).
Focal stenoses, usually less than 2 cm in length, can be difficult to appreciate on conventional radiographs [10]. Likewise, focal stenoses may be overlooked on routine axial CT
images because the orientation of the stenosis is in the plane
of image acquisition. Tracheal stenoses are much better appreciated with coronal reformations and CT virtual endoscopy, which is a view that is helpful to the surgeon [5].
Fig. 4—Normal anatomic variants. Virtual tracheoscopy of distal trachea shows
cartilaginous rings (short thin arrow), posterior tracheal membrane (asterisk),
normal indentation of transverse aorta (thick arrow), and orifice of true tracheal
bronchus supplying right upper lobe (long thin arrow).
Recurrent Respiratory Papillomatosis
Juvenile-onset recurrent respiratory papillomatosis usually begins in the larynx, specifically along the anterior
third of the vocal cords [11], but can spread anywhere in
the tracheobronchial tree. Involvement of the lower airways and lungs occurs in 5–28.8% of patients and carries a
more serious prognosis [11]. Managing this disease may require countless bronchoscopies and laser treatment of dominant papillomas in effort to prevent airway compromise
and malignant degeneration [10]. Between treatments, CT
virtual endoscopy can provide surveillance, particularly in
the evaluation of larger lesions. Although abundant information regarding texture of the mucosa and lesions can be
obtained with fiberoptic imaging (Figs. 7B and 7D), the
relative size of the lesions is nicely depicted on the CT vir-
A
B
Fig. 5—64-year-old man with non–small cell lung cancer.
A, Virtual laryngoscopic image of open glottis shows anterior commissure (thick arrow), laryngeal ventricle (thin arrow), and medialization of right true vocal cord
(asterisk).
B, Axial PET/CT fusion image confirms hypometabolism on right (asterisk) compared with normal left laryngeal uptake.
(Fig. 5 continues on next page)
AJR:192, March 2009
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Thomas et al.
C
D
Fig. 5 (continued)—64-year-old man with non–small cell lung cancer.
C, Virtual tracheoscopy image with abnormal extrinsic compression of distal right trachea caused by mass lesion (asterisk).
D, Axial PET/CT fusion image of chest shows primary tumor.
tual endoscopic images (Figs. 7A and 7C). This noninvasive
examination can be of value to patients who often undergo
countless endoscopic procedures for surveillance, as in the
example of this 23-year-old woman, who was diagnosed at
age 2 with this unrelenting disease that has now progressed
to involve the lung parenchyma (Fig. 7E).
Tracheobronchial Amyloidosis
Tracheobronchial amyloidosis is the most common subtype of pulmonary amyloidosis. The interstitial and nodular parenchymal patterns occur less frequently [11]. Irregular narrowing and thickening of the tracheobronchial wall
are seen routinely on cross-sectional imaging. Here, in a
A
B
Fig. 6—14-year-old male burn patient with tracheal stenosis.
A–C, Virtual tracheoscopy image just above stenosis (arrow, A), correlative conventional endoscopic image (B), and contrast-enhanced coronal CT image (C) show
short segment stenosis and dystrophic calcification in submucosa (arrows, C).
(Fig. 6 continues on next page)
S6
AJR:192, March 2009
CT Virtual Endoscopy of Airway Disease
Fig. 6 (continued)—14-year-old male burn patient with tracheal stenosis.
A–C, Virtual tracheoscopy image just above stenosis (arrow, A), correlative
conventional endoscopic image (B), and contrast-enhanced coronal CT image
(C) show short segment stenosis and dystrophic calcification in submucosa (arrows, C).
C
54-year-old woman who presented initially with shortness
of breath and who was treated with bronchoscopically directed debulking, CT virtual endoscopy shows the airway
lumen and extent of obstruction, which correlate well with
the conventional endoscopic view (Figs. 8A–8C). This can
be differentiated on axial CT from tracheobronchopathia
osteoplastica, which contains calcification in the diseased
tracheal wall and characteristically spares the posterior
membrane. Wegener’s granulomatosis is another infiltrative
disease of the trachea that often involves the subglottic airway, causing stenosis [10, 12]. CT virtual endoscopy has
been shown to increase sensitivity for diagnosing subglottic
stenoses in these patients [12].
Treatment of tracheobronchial amyloidosis is difficult
and historically has been limited to bronchoscopically directed debulking by forceps resection and laser therapy [9].
More recently, external beam radiation therapy (EBRT)
has been described as a viable alternative [13]. Volume-rendering techniques can provide an overview of the infiltrated
tracheal wall, which can potentially help direct EBRT planning (Fig. 8D).
Technical Limitations
Asymmetry is a guide to pathology on endoscopy, but
asymmetries on CT, particularly in the larynx, are most often caused by poor aeration [6]. Because of this, virtual laryngoscopy has low specificity in evaluating mucosal lesions
of the valleculae, pyriform sinuses, and larynx [2]. Therefore, findings on virtual laryngoscopy should always be
evaluated in the context of the original CT data set [2].
The extent of airway compromise may be overestimated on CT virtual endoscopy when the airway is significant-
AJR:192, March 2009
ly stenosed. The apparent degree of stenosis may vary
with different tissue–air threshold values. Lower threshold values increase the apparent stenosis, and higher
thresholds can produce mucosal gaps [3]. This phenomenon is exemplified in the case of polypoid corditis, with
different threshold values yielding different appearances
of the pathology (Fig. 9). The degree of glottic narrowing
must be approximated with the source CT images. In this
case, actual luminal compromise was estimated to be 85%
by conventional endoscopy. Therefore, threshold values
should be tailored to reflect relative lumen size. This can
be performed easily at the workstation by using the mouse
to appropriately “window” the threshold value of the 3D
image or by manually entering different values into the
display options. This also applies to endoluminal lesions.
Note that mass lesion size is generally underestimated using CT virtual endoscopy, and measurements should instead be made from 2D source CT data [4].
To reiterate, the CT virtual endoscopic images shown in
this article were created retrospectively with no changes in
routine departmental scanning protocols (Table 1). However, in the evaluation of distal airway disease, advanced
protocols such as cardiac gating and submillimeter collimation should be considered [14]. Finally, we found no significant qualitative differences in CT virtual endoscopy
images created from the 16-MDCT scanner (Figs. 2 and 8)
versus those generated from the 64-MDCT scanner (Figs. 3
and 6).
Conclusion
CT virtual endoscopy can be a useful adjunct in the
evaluation of large airway disease. It often elicits a favorable
S7
Thomas et al.
A
B
C
D
Fig. 7—23-year-old woman with recurrent respiratory papillomatosis that was diagnosed when she was 2 years old.
A–D, Virtual tracheoscopy from subglottic and distal tracheal images (A and C) show innumerable plaquelike and exophytic lesions. Compare these with correlative
fiberoptic endoscopic images (B and D).
(Fig. 7 continues on next page)
S8
AJR:192, March 2009
CT Virtual Endoscopy of Airway Disease
Fig. 7 (continued)—23-year-old woman with recurrent respiratory papillomatosis that was diagnosed when she was 2 years old.
E, Coronal oblique CT image using lung window setting shows irregularity of
airway and associated pulmonary parenchymal cavities.
E
A
B
Fig. 8—54-year-old woman with tracheobronchial amyloidosis.
A and B, CT virtual endoscopic view (A) and correlative conventional endoscopic view (B) show tracheal narrowing and featureless mucosal surface (asterisk, A).
(Fig. 8 continues on next page)
AJR:192, March 2009
S9
Thomas et al.
C
D
Fig. 8 (continued)—54-year-old woman with tracheobronchial amyloidosis.
C, Contrast-enhanced axial CT image through region of maximal luminal narrowing shows infiltrative thickening of tracheal wall (arrow).
D, Three-dimensional volume-rendered image of trachea shows significant eccentric luminal narrowing (arrow).
A
Fig. 9—Effect of varying tissue–air interface values in CT virtual endoscopy.
A, Preset threshold value of –682 HU exaggerates polypoid lesion and shows artifactual obstruction of glottic opening (arrow).
B, Threshold value of –427 HU better depicts the true lumen size (arrow) as compared with axial CT source image.
S10
B
(Fig. 9 continues on next page)
AJR:192, March 2009
CT Virtual Endoscopy of Airway Disease
Fig. 9 (continued)—Effect of varying tissue–air interface values in CT virtual
endoscopy.
C, Threshold value of –100 HU underestimates glottic narrowing (arrow) and
produces artificial gaps in tissue surfaces.
C
response from referring physicians. Recognizing its limitations is important, however, to interpret it correctly. In
this article, we provide examples to illustrate the usefulness of CT virtual endoscopy. We also present some technical parameters necessary for the success of virtual endoscopy. CT virtual endoscopy provides information to
clinicians in a format they are most familiar with: endoscopy. Like conventional endoscopy, CT virtual endoscopy
can be used for surgical planning, disease monitoring, or
patient education.
References
1.Rogalla P, Nischwitz A, Gottschalk S, Huitema A, Kaschke O, Hamm B. Virtual endoscopy of the nose and paranasal sinuses. Eur Radiol 1998;
8:946–950
2.Byrne AT, Walshe P, McShane D, Hamilton S. Virtual laryngoscopy: preliminary experience. Eur J Radiol 2005; 56:38–42
3.De Wever W, Vandecaveye V, Lanciotti S, Verschakelen JA. Multidetector CTgenerated virtual bronchoscopy: an illustrated review of the potential clinical
indications. Eur Respir J 2004; 23:776–782
4.Summers RM, Shaw DJ, Shelhamer JH. CT virtual bronchoscopy of simulated
endobronchial lesions: effect of scanning, reconstruction, and display settings
and potential pitfalls. AJR 1998; 170:947–950
AJR:192, March 2009
5.Bauer TL, Steiner KV. Virtual bronchoscopy: clinical applications and limitations. Surg Oncol Clin N Am 2007; 16:323–328
6.Henrot P, Blum A, Toussaint B, Troufleau P, Stines J, Roland J. Dynamic maneuvers in local staging of head and neck malignancies with current imaging
techniques: principles and clinical applications. RadioGraphics 2003;
23:1201–1213
7.Westendorff C, Dammann F, Reinert S, Hoffmann J. Computer-aided surgical
treatment of bilateral choanal atresia. J Craniofac Surg 2007; 18:654–660
8.Hafidh MA, Sheahan P, Keogh I, Walsh RM. Acute epiglottitis in adults: a recent experience with 10 cases. J Laryngol Otol 2006; 120:310–313
9.Sulica L. Polyps and Reinke’s edema: distinct laryngeal pathologies with different potential for glottic airway obstruction. Anesth Analg 2005;
100:1863–1864
10.Prince JS, Duhamel DR, Levin DL, Harrell JH, Friedman PJ. Nonneoplastic
lesions of the tracheobronchial wall: radiologic findings with bronchoscopic
correlation. RadioGraphics 2002; 22:S215–S230
11. Soldatski IL, Onufrieva EK, Steklov AM, Schepin NV. Tracheal, bronchial, and
pulmonary papillomatosis in children. Laryngoscope 2005; 115:1848–1854
12.Summers RM, Aggarwal NR, Sneller MC, et al. CT virtual bronchoscopy of
the central airways in patients with Wegener’s granulomatosis. Chest 2002;
121:242–250
13.Neben-Wittich MA, Foote RL, Kalra S. External beam radiation therapy for
tracheobronchial amyloidosis. Chest 2007; 132:262–267
14.Khan MF, Herzog C, Ackermann H, et al. Virtual endoscopy of the tracheobronchial system: sub-millimeter collimation with the 16-row multidetector
scanner. Eur Radiol 2004; 14:1400–1405
S11
AJR Integrative Imaging
1.5 CME
1.0 SAM
LIFELONG LEARNING
FOR RADIOLOGY
CT Virtual Endoscopy in the Evaluation of Large
Airway Disease: Self-Assessment Module
Bradley P. Thomas1, Megan K. Strother, Edwin F. Donnelly, John A. Worrell
ABSTRACT
Objective
The educational objectives of this continuing medical
education activity are for the reader to exercise, self-assess,
and improve skills in diagnostic radiology with regard to
the imaging evaluation of large airway disease and understanding the basics of CT virtual endoscopy techniques as
well as their limitations.
Conclusion
The articles in this activity review the imaging evaluation of large airway disease and the basics and limitations
of CT virtual endoscopy.
INTRODUCTION
This self-assessment module on imaging evaluation of
large airway disease has an educational component and a
self-assessment component. The educational component
consists of three required articles that the participant
should read. The self-assessment component consists of 10
multiple-choice questions with solutions. All of these materials are available on the ARRS Website (www.arrs.org). To
claim CME and SAM credit, each participant must first order the CME activity, then enter his or her responses to the
questions online.
EDUCATIONAL OBJECTIVES
By completing this educational activity, the participant will:
A.Exercise, self-assess, and improve his or her understanding of the evaluation of large airway disease.
B.Understand the basics of CT virtual endoscopy techniques and how the images are produced.
C.Be able to name some disease entities of the large airways
that may be further evaluated with CT virtual endoscopy.
D.Learn some limitations of CT virtual endoscopy.
REQUIRED READING
1.Thomas BP, Strother MK, Donnelly EF, Worrell JA. CT
virtual endoscopy in the evaluation of large airway disease: review. AJR 2009; 192[suppl]:S00–S00
2.Summers RM, Shaw DJ, Shelhamer JH. CT virtual bronchoscopy of simulated endobronchial lesions: effect of
scanning, reconstruction, and display settings and potential pitfalls. AJR 1998; 170:947–950
3.Prince JS, Duhamel DR, Levin DL, Harrell JH, Friedman PJ. Nonneoplastic lesions of the tracheobronchial
wall: radiologic findings with bronchoscopic correlation.
RadioGraphics 2002; 22:S215–S230
INSTRUCTIONS
1.Complete the educational and self-assessment components included in this issue.
2.Visit www.arrs.org and log in.
3.Select Publications/Journals/SAM Articles from the lefthand menu bar.
4.Order the online SAM as directed. (The SAM must be
ordered to be accessed even though the activity is free to
ARRS members.)
5.The SAM can be accessed at www.arrs.org/My Education/My Online Products, but you must be logged in to
access this personalized page.
6.Answer the questions online to obtain SAM credit.
Keywords: airway disease, choanal atresia, CT virtual endoscopy, infiltrative airway disease, transbronchial biopsy
DOI:10.2214/AJR.07.7129
Received October 7, 2008; accepted without revision October 7, 2008.
1
All authors: Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, 1161 21st Ave. S, Nashville, TN 37232-2675. Address correspondence to
B. P. Thomas ([email protected]).
AJR 2009;192:SXX–SXX 0361–803X/09/1923–SX © American Roentgen Ray Society
S1
AJR:192, March 2009
Thomas et al.
QUESTION 1
In CT virtual endoscopy, which of the following
is defined by different threshold values?
A.
B.
C.
D.
Contrast bolus-tracking time.
Tissue–air interface.
Endoscopic field of view.
Postprocessing time.
QUESTION 2
QUESTION 6
For patients with laryngotracheal disease,
CT virtual endoscopy can be useful for which
of the following?
A. Planning transbronchial biopsy.
B. Measuring endoluminal mass lesions.
C. Diagnosing supraglottic malignancy based on
asymmetry.
D. Assessing submucosal disease.
CT virtual endoscopy could be used in the
oropharynx and nasopharynx for which of the
following?
Which is associated with Reinke’s edema?
A.
B.
C.
D.
A.
B.
C.
D.
Diagnosis of a mature paratonsillar abscess.
Assessment of eustachian tube patency.
Visualization of eustachian tube outflow obstruction.
Evaluation of dynamic airway collapse.
QUESTION 7
QUESTION 8
QUESTION 3
When performed during image acquisition,
which of the following may improve the
technical quality of CT virtual endoscopy?
A.
B.
C.
D.
Rapid breathing.
Intravenous contrast.
Modified Valsalva.
Swallowing.
QUESTION 4
Which is a disadvantage of CT virtual endoscopy?
A.
B.
C.
D.
Increased radiation dose.
Poor detection of mucosal lesions.
Inaccurate characterization of stenosis.
Confusing display of anatomy.
QUESTION 5
Which is TRUE when evaluating endoluminal
lesions with CT virtual endoscopy?
A. Measurements do not correlate well with axial CT.
B. Lesion texture may be assessed with threshold values.
C. Source images for CT virtual endoscopy are
routinely purged.
D. Lesion size does not vary with changing threshold
values.
Solution to Question 1
Option B is the best response. The threshold values in CT virtual
endoscopy refer to definition of tissue–air interface [1]. IV contrast
administration has no bearing on CT virtual endoscopy. Option A
is not the best response. Endoscopic field of view is a variable that
can be chosen by the user at the CT workstation. Option C is not
S2
Easily recognizable on axial CT.
Acute surgical emergency.
Chronic airway compromise.
Direct extension throughout airway.
Which is TRUE regarding focal tracheal stenosis?
A.
B.
C.
D.
Common after endotracheal intubation.
High conspicuity on axial CT.
CT virtual endoscopy may characterize the stenosis.
Typically evaluated with fiberoptic endoscopy.
QUESTION 9
Which is TRUE regarding recurrent respiratory
papillomatosis?
A.
B.
C.
D.
Lung involvement has a worse prognosis.
The age of onset is typically over 50 years.
Site of origin is usually in the distal airways.
There is no potential for malignant degeneration.
QUESTION 10
Which of the following is associated with the
most common type of pulmonary amyloidosis?
A. Interstitial infiltrates.
B. Pulmonary nodules.
C. Pleural effusions.
D. Tracheobronchial lesions.
the best response. Postprocessing takes approximately 10 minutes
per examination. Option D is not the best response.
Solution to Question 2
CT virtual endoscopy of the posterior nasopharynx can
further depict hypertrophy of the adenoid tonsils and the re-
AJR:192, March 2009
CT Virtual Endoscopy of Airway Disease
lationship to the eustachian tubes, an area that is difficult to
appreciate with conventional CT [2]. Option C is the best response. The eustachian tube itself cannot be evaluated because it is not normally an air-filled structure. Option B is not
the best response. Although some mass effect may be seen
with a paratonsillar abscess, it would not be further differentiated from paratonsillar phlegmon or other cause of mass effect with CT virtual endoscopy alone. Option A is not the best
response. CT virtual endoscopy is usually postprocessed from
static CT images and therefore is unable to evaluate dynamic
airway collapse. Option D is not the best response.
Solution to Question 3
Airway distension maneuvers such as a modified Valsalva
maneuver may help to improve symmetry of the upper airways [3]. Option C is the best response. Having the patient
swallow or breathe rapidly would introduce motion artifact;
Options A and D are not the best responses. Administration of
IV contrast material has not been shown to be useful in CT
virtual endoscopy. Option B is not the best response.
Solution to Question 4
CT virtual endoscopy is not well-suited for the evaluation
of mucosal lesions [4]. Option B is the best response. CT virtual endoscopy can help to display complex 3D anatomy and
provide useful images from unconventional endoscopic views.
Options C and D are not the best responses. There is no added
cost or radiation with CT virtual endoscopy. Option A is not
the best response.
Solution to Question 5
Measurements on CT virtual endoscopy do not correlate
well with conventional axial CT images [5]. Option A is the
best response. Lesion size will vary with different tissue–air
threshold values, so option D is not the best response. Lesion texture cannot be readily assessed with CT virtual endoscopy; option B is not the best response. Furthermore,
CT virtual endoscopy should not be interpreted without using the source images. Option C is not the best response.
Solution to Question 6
CT virtual endoscopy is useful in transluminal biopsy
planning [6]. Option A is the best response. However, submucosal extent of disease cannot be assessed using standard surface-rendered virtual endoscopic images. Option D
is not the best response. Lack of airway distension is a common cause of asymmetry and not a reliable indicator of
supraglottic malignancy using CT virtual endoscopy. Option C is not the best response. Measurement of endoluminal
mass lesions has been shown to be inaccurate with CT virtual endoscopy. Option B is not the best response.
Solution to Question 7
Reinke’s edema can have a diffuse, polypoid distribution
that can cause airway compromise [7], which means option
AJR:192, March 2009
C is the best response. It usually has a chronic course and is
not an acute surgical emergency. Option B is not the best
response. It may not be seen with conventional CT or CT
virtual endoscopy, depending on the degree of true cord
edema. Option A is not the best response. Reinke’s edema is
a laryngeal disease caused by chronic irritation and does
not spread to other parts of the airway. Option D is not the
best response.
Solution to Question 8
CT virtual endoscopy is useful for evaluating tracheal
stenosis by further depicting the length of the stenosis
and assessment of the distal airway [6]. Option C is the
best response. Although iatrogenic causes are the reason
for focal tracheal stenoses, the incidence after endotracheal intubation is less than 1% [8]. Option A is not the best
response. Tracheal stenosis can easily be overlooked on
routine axial CT images because the focal stenosis is in the
imaging plane. Option B is not the best response. Fiberoptic endoscopy is invasive and carries the risk of airway
compromise; CT virtual endoscopy is noninvasive. Option
D is not the best response.
Solution to Question 9
Recurrent respiratory papillomatosis has a worse prognosis when it involves the distal airways [9]. Option A is
the best response. Recurrent respiratory papillomatosis
usually begins in the larynx, not the distal airways. Option C is not the best response. It is a disease of younger,
not older patients. Option B is not the best response. This
disease process can cause significant morbidity, including
malignant degeneration of papillomas [8]. Option D is not
the best response.
Solution to Question 10
Tracheobronchial amyloidosis is the most common of the
three types of pulmonary amyloidosis [8]. Option D is the
best response. The nodular and interstitial forms are less
common. Options A and B are not the best responses. Pleural effusions are not specific for this disease. Option C is not
the best response.
References
1. De Wever W, Vandecaveye V, Lanciotti S, Verschakelen JA. Multidetector CTgenerated virtual bronchoscopy: an illustrated review of the potential clinical
indications. Eur Respir J 2004; 23:776–782
2. Rogalla P, Nischwitz A, Gottschalk S, Huitema A, Kaschke O, Hamm B. Virtual endoscopy of the nose and paranasal sinuses. Eur Radiol 1998; 8:946–950
3. Henrot P, Blum A, Toussaint B, Troufleau P, Stines J, Roland J. Dynamic maneuvers in local staging of head and neck malignancies with current imaging
techniques: principles and clinical applications. RadioGraphics 2003;
23:1201–1213
4. Byrne AT, Walshe P, McShane D, Hamilton S. Virtual laryngoscopy: preliminary experience. Eur J Radiol 2005; 56:38–42
5. Summers RM, Shaw DJ, Shelhamer JH. CT virtual bronchoscopy of simulated
endobronchial lesions: effect of scanning, reconstruction, and display settings
and potential pitfalls. AJR 1998; 170:947–950
S3
Thomas et al.
6. Bauer TL, Steiner KV. Virtual bronchoscopy: clinical applications and limitations. Surg Oncol Clin N Am 2007; 16:323–328
7. Sulica L. Polyps and Reinke’s edema: distinct laryngeal pathologies with different potential for glottic airway obstruction. Anesth Analg 2005;
100:1863–1864
S4
8. Prince JS, Duhamel DR, Levin DL, Harrell JH, Friedman PJ. Nonneoplastic
lesions of the tracheobronchial wall: radiologic findings with bronchoscopic
correlation. RadioGraphics 2002; 22[spec no]:S215–S230
9. Soldatski IL, Onufrieva EK, Steklov AM, Schepin NV. Tracheal, bronchial, and
pulmonary papillomatosis in children. Laryngoscope 2005; 115:1848–1854
AJR:192, March 2009
AJR Integrative Imaging
1.5 CME
1.0 SAM
LIFELONG LEARNING
FOR RADIOLOGY
Radiologic Signs in Thoracic Imaging:
Case-Based Review and Self-Assessment Module
Mark S. Parker1, Marvin H. Chasen2, Narinder Paul3
ABSTRACT
Objective
Chest imaging remains one of the most complicated subspecialties of diagnostic radiology. The successful interpretation of thoracic imaging studies requires the recognition
and understanding of the radiologic signs that are characteristic of many complex disease processes.
Conclusion
The educational objectives for this case-based self-assessment module are for the participant to exercise, self-assess,
and improve his or her understanding of important thoracic radiologic signs that are useful in establishing the diagnosis of particular diseases of the chest.
INTRODUCTION
This self-assessment module on several radiologic signs
used in thoracic imaging to assist radiologists in establishing
a particular diagnosis of pathologic processes affecting the
chest has a self-assessment component and an educational
component. The self-assessment component consists of six
previously unpublished case-based studies with accompanying clinical histories and radiologic images. These cases have
been selected to illustrate specific radiologic imaging signs. A
series of multiple-choice questions follows each case, with solutions and a discussion of that particular radiologic sign and
its cause. The educational component consists of suggested
readings or references that accompany each case that the participant should review. To claim CME and SAM credit, each
participant must log on to the ARRS Website (www.arrs.org)
and enter his or her responses to the questions online.
EDUCATIONAL OBJECTIVES
By completing this educational activity, the participant will:
A.Exercise, self assess, and improve his or her understanding
of selected radiologic signs useful in establishing a particular diagnosis of pathologic processes affecting the chest.
B.Exercise, self assess, and improve his or her understanding
of the underlying cause for these particular imaging signs.
REQUIRED ACTIVITIES
1.Six interactive case scenarios presented in this article.
RECOMMENDED READING
1.Woodring JH, Reed JC. Radiographic manifestations
of lobar atelectasis. J Thorac Imaging 1996; 11:109–144
2.Catalano O. The incomplete border sign. Radiology 2002;
225:129–130
3.Chung M, Edinburgh K, Webb E, McCowin M, Webb W.
Mixed infiltrative and obstructive disease on high-resolution CT: differential diagnosis and functional correlates in
a consecutive series. J Thorac Imaging 2001; 16:69–75
4.Whitten CR, Khan S, Munneke GJ, Grubnic S. A diagnostic approach to mediastinal abnormalities. RadioGraphics 2007; 27:657–671
5.Ferguson EC, Krishnamurthy R, Oldham SA. Classic
imaging signs of congenital cardiovascular abnormalities. RadioGraphics 2007; 27:1323–1334
6.Marshall GB, Farnquist BA, MacGregor JH, Burrowes
PW. Signs in thoracic imaging. J Thorac Imaging 2006;
21:76–89
INSTRUCTIONS
1.Complete the educational and self-assessment components included in this issue.
2.Visit www.arrs.org and log in.
3.Select Publications/Journals/SAM Articles from the lefthand menu bar.
4.Order the online SAM as directed. (The SAM must be
ordered to be accessed even though the activity is free to
ARRS members.)
5.The SAM can be accessed at www.arrs.org/My Education/My Online Products, but you must be logged in to
access this personalized page.
6.Answer the questions online to obtain SAM credit.
Keywords: “head cheese sign,” “hilum convergence sign,” “hilum overlay sign,” “hogs head cheese sign,” “incomplete border sign,” luftsichel sign, thoracic imaging, “walking
man sign,” “water bottle sign”
DOI:10.2214/AJR.07.7081
Received March 9, 2008; accepted after revision July 11, 2008.
M. S. Parker is a design consultant for Worldwide Innovations and Technologies, Inc., Overland Park, KS.
1
Department of Radiology, Medical College of Virginia Hospitals–VCU Health System, Main Hospital, 3rd Floor, 1250 E Marshall St., PO Box 980615, Richmond, VA 23298-0615. Address
correspondence to M. S. Parker ([email protected]).
Department of Diagnostic Radiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX.
2
Department of Medical Imaging, Thoracic Imaging, University of Toronto, Toronto, ON, Canada.
3
AJR 2009;192:SXX–SXX 0361–803X/09/1923–SX © American Roentgen Ray Society
S1
AJR:192, March 2009
Parker et al.
Scenario 1
Clinical History
A 52-year-old woman presented to her primary care physician with a several-week history of nonproductive cough,
mild dyspnea, chest tightness, and wheezing (Fig. 1).
Description of Images
Frontal chest radiography (Fig. 1A) shows an ill-defined left
perihilar opacity partially silhouetting the left heart border.
QUESTION 1
What is the MOST LIKELY diagnosis?
A.
B.
C.
D.
E.
Pulmonary edema.
Pneumonia.
Atelectasis.
Mediastinal mass.
Left apical pneumothorax.
A
Fig. 1—52-year-old woman with several-week history of nonproductive cough,
mild dyspnea, chest tightness, and wheezing.
A, Posteroanterior chest radiograph shows ill-defined left perihilar opacity
partially silhouetting left heart border. Note ipsilateral cephalad hilar displacement and bronchovascular reorientation as well as leftward displacement of
tracheal air column. Left thorax appears smaller in volume than right. Left
diaphragm is elevated and shows juxtaphrenic peak. Left apex is hyperlucent, as
is left paramediastinal border.
S2
There is ipsilateral cephalad hilar displacement and bronchovascular reorientation as well as leftward displacement of the
tracheal air column. The left thorax appears smaller in volume than the right. The left diaphragm is elevated and shows
a juxtaphrenic peak. The left apex is hyperlucent, as is the left
paramediastinal border. Note the luftsichel sign.
Diagnosis
The diagnosis is luftsichel sign of left upper lobe collapse
secondary to an obstructing endobronchial carcinoid tumor
(Kulchitsky cell type I).
Solution to Question 1
The radiographic features of pulmonary edema may include an increased cardiothoracic ratio, widening of the vascular pedicle, vascular redistribution or engorgement, discrepant arterial-to-bronchial ratios, interstitial Kerley lines,
and possibly pleural effusions [1, 2]. Option A is not the best
response because none of these signs is present. Pure pneumonia is an air-space-replacing process characterized by an
equal exchange of air in the alveoli for pus and thus preservation of lung volume [3, 4]. Therefore, Option B is not the best
response. Option D is not the best response because the location and morphology of the perihilar opacity support a parenchyma-based, not a mediastinum-based, lesion.
Option C, atelectasis, and left upper lobe atelectasis in particular, is the best response. This case illustrates both direct and
many indirect signs of volume loss. More important, the case
shows the luftsichel sign. “Luftsichel,” which is German for
“air crescent,” is an indirect sign of overinflation characterized
by hyperexpansion of the superior segment of the left lower
lobe and its insinuation between the collapsed upper lobe and
the mediastinum. This particular imaging sign is seen in the
setting of left upper lobe atelectasis and is a manifestation of
compensatory overinflation in response to the upper lobe volume loss [5]. Because of the absence of a horizontal fissure in
the left thorax, as the upper lobe loses volume, the oblique fissure becomes vertically oriented in a plane roughly parallel to
the anterior chest wall. The oblique fissure continues to shift
further anteriorly and medially, with progressive volume loss
until the atelectatic upper lobe is contiguous with the left heart
border and partially silhouetting its border (i.e., the silhouette
sign) and creating an ill-defined parahilar haze (i.e., the “veil
sign”) on the frontal examination [5–8].
As the apical segment of the collapsing upper lobe moves
anteromedially, the superior segment of the left lower lobe
overinflates and fills in the vacated apex with aerated lung
that can mimic an apical pneumothorax; option E is not the
best response. However, the observation of additional indirect
signs of volume loss, such as the juxtaphrenic peak, diaphragmatic elevation, and the partial loss of definition of the left
heart border, allow the appropriate differentiation. Additionally, a true pneumothorax can be confidently diagnosed by
the recognition of a white visceral pleural line as opposed to a
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Thoracic Imaging
B
Fig. 1—52-year-old woman with several-week history of nonproductive
cough, mild dyspnea, chest tightness, and wheezing.
B, Lateral chest radiograph shows retrosternal sigmoid-shaped band of
increased opacity representing anteriorly displaced oblique fissure secondary
to complete collapse of left upper lobe.
black edge due to a Mach effect [9, 10]. Such a white visceral
pleural reflection is not present in this patient. Furthermore,
a true visceral pleural reflection will also follow the contour of
the lung periphery and not simply fade imperceptibly with
the lung parenchyma, as was also seen in our patient [9, 10].
However, radiologists should be cautioned about the uncommon relationship between lobar atelectasis and pneumothorax. A localized pneumothorax may occur adjacent
to an atelectatic lobe and has been described as a sign of
bronchial obstruction that is referred to as “pneumothorax
ex vacuo.” In such cases, treatment should be directed to
the underlying bronchus and not to the pleural space [11].
The overinflated superior segment of the lower lobe may
insinuate itself between the collapsed upper lobe and the
transverse aorta, creating a sharp crisp crescent or paraaortic radiolucency referred to as the luftsichel sign. The diagnosis of left upper lobe collapse on single anteroposterior or
posteroanterior chest radiographs can sometimes be difficult. When a lateral chest radiograph is available (Fig. 1B),
the diagnosis of left upper lobe collapse is more easily made
by noting a retro­sternal sigmoid-shaped band of increased
opacity representing the anteriorly displaced oblique fissure
AJR:192, March 2009
delineating the collapsed upper lobe from the overinflated
lower lobe [5–8]. However, observing additional indirect
signs of volume loss (e.g., ipsilateral mediastinal shift, hilar
elevation, diaphragmatic elevation, juxtaphrenic peak, rib
approximation, and so forth) will enable the radiologist to
confidently make the best diagnosis, even in the absence of
a lateral chest radiograph.
The luftsichel sign is a classic and helpful imaging finding
on frontal chest radiography. Once lobar atelectasis has
been identified, the cause (e.g., mucus plug, aspirated foreign body, primary or secondary obstructing endobronchial
tumors, and so forth) must be determined either through
bronchoscopy or CT evaluation.
Endobronchial carcinoids are rare neuroendocrine tumors,
accounting for approximately 2% of all lung neoplasms and
12–15% of all carcinoid tumors [12, 13]. These tumors originate from bronchial mucosa neurosecretory cells and are
classified as low-grade malignant neoplasms because of their
potential for local invasion, local recurrence, and occasional
metastasis [12, 13]. Endobronchial carcinoids have the potential to synthesize and secrete various peptide hormones
and neuroamines (e.g., adrenocorticotropic hormone, serotonin, somatostatin, and bradykinin). These tumors are not
associated with smoking [12–14]. Histologically, carcinoid
tumors are categorized as either Kulchitsky cell carcinoma
(KCC) type I (i.e., typical carcinoid) or KCC type II (i.e.,
atypical carcinoid). KCC type I is the classic endobronchial
carcinoid and is the least aggressive [12, 13]. These lesions are
usually well defined, are smaller than 2.5 cm in diameter, are
located centrally in the mainstem bronchi, and affect relatively young patients, with a marked female predilection
(10:1, females to males). Only 3% of typical carcinoid tumors metastasize to sites other than regional lymph nodes.
The prognosis is excellent, with a 5-year survival rate of 92%
[12–14]. KCC type II is the atypical carcinoid tumor and is
responsible for 25% of pulmonary carcinoid tumors [12, 13].
These latter lesions tend to behave more aggressively, are
larger, occur in peripheral locations, and usually affect older
patients, with a male preponderance. Regional lymph node
metastases are more common, occurring in up to 50% of patients. Distant metastases to the liver, bone, and CNS occur
in one third of patients [12–14]. The prognosis is less favorable, with a 5-year survival rate of 69%. Surgical excision is
the preferred treatment, typically lobectomy or pneumonectomy. Tracheobronchial sleeve resection may be used for central carcinoid lesions with normal distal lung parenchyma.
CT can prospectively evaluate the likelihood of tumor resection and is valuable in monitoring patients postoperatively
for potential recurrence [12–14].
Treatment
The treatment is left upper lobectomy. The patient has
since relocated and is now being followed up at another institution. The current disease status is otherwise unknown.
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Description of Images
A frontal chest radiograph (Fig. 2A) reveals a vague
opacity in the right midthorax overlying the fourth and
fifth anterior ribs. The ribs appear intact. The inferior
margin of this mass is well delineated; however, the superior margin is ill-defined or incomplete. On lateral chest
radiography (Fig. 2B), the lesion appears better defined
and is lentiform in morphology. The long axis of this mass
parallels the long axis of the right oblique fissure. The anterior, superior, and inferior borders appear better defined
than the posterior border. Chest CT using the mediastinal
window setting (Fig. 2C) reveals a large, slightly lobulated
homogeneous mass. Two subtle punctuate hypervascular
foci are seen in the periphery of the lesion. Lung window
settings (Figs. 2D and 2E) confirm the lesion is localized to
the right oblique fissure.
Question 2
Question 3
Scenario 2
Clinical History
A 68-year-old asymptomatic nonsmoking woman underwent preoperative screening chest radiography in preparation for a total knee arthroplasty. The radiographic findings
prompted subsequent chest CT (Fig. 2).
Where is this lesion MOST LIKELY located?
What is the MOST LIKELY diagnosis?
A.
B.
C.
D.
A.
B.
C.
D.
Lung parenchyma.
Mediastinum.
Pleura.
Chest wall.
A
Primary lung cancer.
Chest wall chondrosarcoma.
Pseudotumor or vanishing tumor of the pleura.
Localized fibrous tumor of the pleura.
B
Fig. 2—68-year-old asymptomatic nonsmoking woman who underwent preoperative screening chest radiography in preparation for total knee arthroplasty.
Radiographic findings prompted subsequent chest CT.
A, Frontal chest radiograph reveals vague opacity in right midthorax overlying fourth and fifth anterior ribs. Ribs appear intact. Inferior margin of this mass is well
delineated; however, superior margin is ill-defined or incomplete.
B, On lateral chest radiograph, lesion appears better defined and is lentiform in morphology. Long axis of this mass parallels long axis of right oblique fissure.
Anterior, superior, and inferior borders appear better defined than posterior border.
(Fig. 2 continues on next page)
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Thoracic Imaging
Solution to Question 2
Extrapulmonary masses, when projected en face to the
x-ray beam, can simulate the presence of an intraparenchymal lesion [15]. The incomplete border sign illustrated in
this patient is useful in distinguishing between extrapulmonary (options B, C, and D) and intrapulmonary (option A)
lesions. Option A is not the best response. Appropriate localization is necessary before the proper differential diagnosis can be determined.
Extrapulmonary masses often exhibit tapered or ovoid superior and inferior borders and are convex toward the lung
[15]. The overlying pleura of extrapulmonary lesions
smoothes out surface irregularities which, combined with the
interface of the mass with lung air, give it a relatively sharply
defined appearance [15]. However, this otherwise sharp border may be lost where the mass becomes continuous with the
C
D
Diagnosis
The diagnosis in this patient is localized fibrous tumor of
the pleura, as indicated by the incomplete border sign.
Fig. 2 (continued)—68-year-old asymptomatic nonsmoking woman who
underwent preoperative screening chest radiography in preparation for total
knee arthroplasty. Radiographic findings prompted subsequent chest CT.
C, Chest CT scan at mediastinal window setting reveals large, slightly
lobulated homogeneous mass. Two subtle punctuate hypervascular foci are
seen in periphery of lesion.
D and E, CT images at lung window settings confirm lesion is localized to right
oblique fissure.
AJR:192, March 2009
E
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Parker et al.
pleura of the chest wall, thus forming an incompletely visualized border on radiography (Figs. 2A and 2B) and creating
the so-called incomplete border sign [15–17].
Mediastinum- and chest wall–based masses may also
show an incomplete border sign [15]. However, the location
of this lesion on the frontal radiograph (Fig. 2A) would argue against a mediastinal or chest wall cause. Options B
and D are not the best responses. Localization of the lesion
to the oblique fissure on the lateral chest radiograph (Fig.
2B) supports a pleural cause, which is subsequently confirmed on CT (Figs. 2C–2E). Option C is the best response.
The most common extrapulmonary lesions include, but
are not limited to, loculated pleural effusions, various rib
lesions (e.g., fractures, primary and secondary tumors),
mesenchymal tumors, neural tumors, hematomas, lipomas,
and various cutaneous lesions (e.g., neurofibromas) [15].
Solution to Question 3
The incomplete border sign supports a conclusion that
the lesion in question is extrapulmonary. Option A is not
the best response.
Although chest wall metastases are the most common malignant chest wall neoplasm in adults, chondrosarcoma is the
most common primary malignant tumor of the adult chest
wall [18–20]. Chondrosarcomas are malignant neoplasms
with cartilaginous differentiation. Option B is not the best
response. This neoplasm typically arises in the anterior chest
wall and involves the sternum or costochondral cartilages.
Less frequently, chondrosarcomas arise in the ribs (17%) and
scapulae [18–20]. Chondrosarcomas occur across a wide age
range but typically affect patients between the ages of 30
and 60 years. Most tumors manifest as palpable chest wall
masses that may grow rapidly and become painful [18–20].
Males are affected slightly more frequently than females, in a
ratio of 1.3:1.0 [18–20]. On radiologic imaging, variable
intratumoral calcifications (e.g., rings, arches, flocculent, or
stippled) can be identified, and osseous destruction is often
present [18–20]. Surgical resection is the treatment of choice.
The 5-year survival rate is more than 60% and may approach
80% in patients without metastases. Poor prognosis is associated with incomplete tumor resection, metastases, local recurrence, and patient age older than 50 years [18–20].
Interlobar pleural fluid collections are typically ovoid or
lentiform when viewed in tangent and may simulate a mass
on conventional radiography [21]. The long axis of such
Scenario 3
Clinical History
A 33-year-old man presented with a 3- to 4-day history
of dyspnea and a nonproductive cough. A chest radiograph
(not shown) revealed bilateral perihilar air-space opacities
with intervening normal aerated lung. He was admitted to
the general medicine ward with a presumptive diagnosis
S6
fluid collections is usually oriented along the long axis of
the interlobar fissure [21]. Fluid has a tendency to accumulate in the interlobar fissure in the setting of cardiac decompensation and to localize in the horizontal fissure in particular [21]. The fluid collections tend to be spontaneously
absorbed when the heart failure has been relieved and are
therefore referred to as either pseudotumors or vanishing
tumors of the pleura [21]. Option C is not the best response.
Invariably, concomitant radiographic evidence of cardiac
decompensation is seen or an ipsilateral pleural effusion is
present [21].
Localized or solitary fibrous tumor of the pleura is a rare
pleural neoplasm but is the second most common primary
pleural neoplasm after malignant mesothelioma [22–24].
Option D is the best response. Although most of these tumors are related to the pleura, they have also been described
in other intra- and extrathoracic locations. These tumors
typically occur in adult men and women in the fifth through
eighth decades of life. Many patients are asymptomatic
and are diagnosed incidentally because of abnormal chest
radiographic findings, as in our patient (Figs. 2A and 2B).
Symptoms typically relate to tumor size and include cough,
chest pain, and dyspnea. Hypertrophic pulmonary osteoarthropathy is seen in 20–25% of patients. Symptomatic hypoglycemia occurs in less than 5% of patients [22–24]. Radiographically, localized fibrous tumors of the pleura
present as well-defined, variably sized, lobular extrapulmonary nodules or masses (i.e., incomplete border sign) and
typically abut the pleura [23, 24] (Figs. 2A and 2B). CT reveals a noninvasive lobular soft-tissue mass of variable size
that abuts at least one pleural surface or may exhibit an
interlobar fissure location (Figs. 2C–2E). Smaller lesions are
more homogeneous in attenuation, whereas larger lesions
may appear heterogeneous. Foci of calcification and enhancing vessels may be observed in the lesion [23, 24] (Fig.
2C). These tumors are not related to mesothelioma, asbestos exposure, or tobacco abuse. Benign and malignant variants have been described. Prognosis is related more to resectability than to histologic features [22–24].
Treatment
The tumor was successfully resected in its entirety at
open thoracotomy. The patient remained disease-free at the
time of the last follow-up CT examination 12 months before
this writing.
of community-acquired pneumonia and began taking
levofloxacin. Over the next 3 days, he developed progressive hypoxia and was subsequently transferred to the intensive care unit for mechanical ventilation and nitric oxide therapy. Follow-up chest radiography (not shown)
before intubation revealed progressive bilateral perihilar
air-space disease. Subsequent chest CT pulmonary angiography on the same day did not show a pulmonary emAJR:192, March 2009
Thoracic Imaging
A
B
Fig. 3—33-year-old man with 3- to 4-day history of dyspnea and nonproductive
cough. Chest radiograph (not shown) revealed bilateral perihilar air-space opacities with intervening normal aerated lung. Patient was admitted to general
medicine ward with presumptive diagnosis of community-acquired pneumonia
and began taking levofloxacin. Over next 3 days he developed progressive
hypoxia and was subsequently transferred to intensive care unit for mechanical
ventilation and nitric oxide therapy. Follow-up chest radiograph (not shown)
before intubation revealed progressive bilateral perihilar air-space disease.
A–C, Selected chest CT pulmonary angiography images using lung window
setting through upper (A), mid (B), and lower (C) lung zones reveal patchy
pattern of variable attenuation characterized by combination of ground-glass
opacities, consolidations, reduced lung attenuation resulting from mosaic
perfusion, and intervening normal lung.
C
bolus but did reveal an interesting pattern of air-space
disease (Fig. 3).
Description of Images
The selected CT images (Fig. 3) through the upper, mid,
and lower lung zones reveal a patchy pattern of variable
Question 4
Which diagnosis would be LEAST LIKELY?
A.
B.
C.
D.
Sarcoidosis.
Atypical infection with associated bronchiolitis.
Hypersensitivity pneumonitis.
Multiple septic pulmonary emboli.
AJR:192, March 2009
attenuation characterized by a combination of groundglass opacities, consolidations, reduced lung attenuation
resulting from mosaic perfusion, and intervening normal
lung. Note the “head cheese sign.”
Diagnosis
The diagnosis is Mycoplasma pneumonia with associated
bronchiolitis, as indicated by the head cheese sign.
Solution to Question 4
The combination of mixed densities in the lung parenchyma created by ground-glass opacities, air-space consolidations, reduced lung attenuation from mosaic perfusion, and
intervening normal lung give the lung a geographic appearance on CT [25, 26] (Fig. 3). This pattern of mixed parenchymal lung densities has been likened to the morphologic appearance of the mixture of boiled pork scraps and pigs’ feet
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in a gelatinous background known and marketed as head
cheese or hog’s head cheese and is therefore known as the
“head cheese sign” or “hog’s head cheese sign” [25, 26]. How
does this particular imaging sign help radiologists in their diagnostic interpretation? CT must clearly show areas of
ground-glass opacity and consolidation with concomitant
mosaic perfusion (rather than one or the other) (Fig. 3). When
these findings are present, they indicate a mixed infiltrative
disease characterized by ground-glass or consolidation and
an obstructive disease (usually associated with bronchiolitis)
characterized by mosaic perfusion, with a decrease in vessel
caliber and side branches in the hypoattenuating regions of
lung parenchyma. The latter will often reveal air trapping on
expiratory images [25–27]. The most common clinical causes
of this CT pattern of disease include hypersensitivity pneumonitis, sarcoidosis, atypical infections (e.g., those caused by
Mycoplasma pneumoniae) with associated bronchiolitis, and
acute interstitial pneumonia [25–27]. Options A, B, and C,
which are likely diagnoses, are not the best responses. Additional clinical and laboratory data would be necessary to further narrow the differential diagnosis. In this particular case,
the diagnosis was an atypical infection with associated bronchiolitis secondary to Mycoplasma pneumonia.
The CT pattern of multiple septic pulmonary emboli is
much different. The latter disease process may be characterized by unilateral or bilateral areas of juxtapleural and
wedge-shaped consolidation; diffuse, often angiocentric,
nodules ranging from 0.5 to 3.5 cm in diameter, many of
which show various stages of cavitation; and a peripheral
rimlike pattern of enhancement after the administration of
IV contrast media. Pleural effusions may also be identified
in two thirds of patients, and 27% have identifiable hilar or
mediastinal lymphadenopathy [28]. On the basis of the
clinical presentation and the CT findings, Option D, multi-
ple septic pulmonary emboli, would be the least likely diagnosis; therefore, option D is the best response.
Mycoplasmas are bacteria that lack a cell wall, adhere to
ciliated respiratory epithelium, and produce hydrogen peroxide, which damages epithelial cells and interferes with
ciliary function. M. pneumoniae are one of three human
pathogenic Mycoplasma species [29]. Bacteria are transmitted from person to person thorough aerosolized droplets.
Infection may occur the year round but usually occurs during fall and winter [29, 30]. Patients may present with fever,
chills, malaise, anorexia, sore throat, dry cough, and headache. As the disease progresses, nearly all patients develop
an intractable hacking cough, but only 3% of such patients
develop pneumonia. Extrapulmonary features are common
and may include cervical lymphadenopathy, skin rash,
aseptic meningitis, nausea, vomiting, and diarrhea. Rarely,
patients present with or develop acute respiratory distress
syndrome [29–31]. Such patients have higher morbidity
and mortality rates. In these latter cases, supportive mechanical ventilation is necessary in addition to corticosteroids and antibiotic therapy (e.g., erythromycin, azithromycin, tetracycline, clarithromycin, and so forth) [29–31].
After infection, patients may fully recover; or interstitial
fibrosis, bronchiectasis, Swyer-James syndrome, and impaired pulmonary function may develop as sequelae of the
infection [29, 30].
Treatment
Treatment is support with a mechanical ventilator and
nitric oxide therapy, corticosteroids, and clarithromycin.
The patient was maintained on mechanical ventilation
for 5 days and then was successfully extubated. Eight
days later, he was discharged and was subsequently lost
to follow-up.
Scenario 4
Clinical History
A 35-year-old woman presented with fatigue, chest pain,
and weight loss over the past several months (Fig. 4).
Description of Images
A posteroanterior (Fig. 4A) chest radiograph shows a massively enlarged cardiomediastinal silhouette. Lateral chest
radiography (not shown) showed complete obliteration of
the retrosternal clear space. On closer inspection, the normal
right and left pulmonary arteries and their respective interlo-
A
S8
Fig. 4—35-year-old woman with fatigue, chest pain, and weight loss over past
several months.
A, Posteroanterior chest radiograph shows massively enlarged cardiomediastinal silhouette. Lateral chest radiograph (not shown) showed complete obliteration
of retrosternal clear space. On closer inspection, normal right and left pulmonary
arteries and their respective interlobar divisions can be identified well in what
appears to be lateral or peripheral margin of cardiomediastinal silhouette.
(Fig. 4 continues on next page)
AJR:192, March 2009
Thoracic Imaging
bar divisions can be identified well in what appears to be the
lateral or peripheral margin of the cardiomediastinal silhouette. Contrast-enhanced CT images (mediastinal window setting) through the main pulmonary artery level (Fig. 4B) and
Diagnosis
The diagnosis is malignant peripheral nerve sheath tumor of the vagus nerve with mediastinal invasion, the hilum overlay sign.
Question 5
What is the MOST LIKELY diagnosis?
A.
B.
C.
D.
the myocardium (Fig. 4C) show a large aggressive anterior
mediastinal mass intimately related to the ascending aorta
and main pulmonary artery with invasion of the myocardium proper. A small pericardial effusion is present.
Cardiomyopathy.
Pericardial effusion.
Anterior mediastinal mass.
Pleural effusion.
Solution to Question 5
The proximal segment of the visible left or right pulmonary artery lies laterally to the cardiac silhouette or just
within its edge on normal frontal chest radiography. As
the myocardium enlarges in the setting of a cardiomyopathy or cardiomegaly or as the pericardial sac distends with fluid from pericardial effusion, the pulmonary
artery segments are simply displaced outward but continue this same relationship to the cardiac silhouette [32,
33]. Options A and B are not the best responses. Alternatively, if either the left or right pulmonary artery can be
seen 1.0 cm or more within the lateral edge of an opacity
that appears to represent the cardiac silhouette, that opacity does not represent the cardiac silhouette and therefore
cannot be the result of cardiomyopathy, cardiomegaly, or
pericardial effusion, but is related instead to the presence
of an anterior mediastinal mass [32, 33]. Option C is the
best response. This is referred to as the hilum overlay sign,
which can be used to determine that a lesion is extracardiac and localized to the anterior mediastinal compart-
Question 6
All of the following are TRUE statements
regarding the “hilum convergence sign” EXCEPT:
A. It differentiates a potential hilar mass from an
enlarged pulmonary artery.
B. If the pulmonary arteries converge into the lateral
border of the apparent hilar mass, the mass
represents an enlarged pulmonary artery.
C. If the pulmonary arteries converge behind the
apparent hilar mass, the mass represents an
enlarged pulmonary artery.
D. If the convergence of the pulmonary arteries
arises from the cardiac silhouette, a mediastinal
mass is likely present.
B
C
Fig. 4 (continued)—35-year-old woman with fatigue, chest pain, and weight loss over past several months.
B and C, Contrast-enhanced chest CT scans using mediastinal window setting through main pulmonary artery level (B) and myocardium proper (C) show large
aggressive anterior mediastinal mass intimately related to ascending aorta and main pulmonary artery as well as invasion of myocardium proper. Small pericardial
effusion is present. DA = descending thoracic aorta, LLPA = left lower lobe pulmonary artery, PA = pulmonary artery, PV = pulmonary vein, RLPA = right lower lobe
pulmonary artery, RA = right atrium, RV = right ventricle.
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ment, thus steering the differential diagnosis in the appropriate direction [32, 33]. Because the lesion of concern is
mediastinum-based, option D, pleural effusion, is not the
best response. It likewise would be quite unusual for pleural effusion to present as perihilar ground-glass opacity.
Additionally, the costophrenic angles are preserved. The
mediastinal mass in this particular patient proved to be a
malignant peripheral nerve sheath tumor (MPNST) arising from the intrathoracic vagus nerve in the mediastinum. MPNSTs are rare but aggressive sarcomas that arise
from the nerve sheath or show features of nerve sheath
differentiation; they more often involve the extremities,
the head, and the neck. Intrathoracic MPNST is uncommon [34]. Although such tumors may occur in patients
with neurofibromatosis 1 (von Recklinghausen’s disease)
with an incidence of 0.16%, these tumors may also occur in
patients with no signs of such (incidence of 0.001%), as in
our patient [34–36]. Successful treatment requires complete
surgical excision of the MPNST. Radiotherapy may delay
recurrence but has little impact on patient survival. Conventional advanced soft-tissue sarcoma single-agent chemotherapy with doxorubicin has a poor response rate [34].
Solution to Question 6
Felson’s hilum convergence sign should be differentiated
from the hilum overlay sign discussed in the solution to question 5 [32]. The hilum convergence sign is useful in distinguishing between a large pulmonary artery and a hilar mass [32].
Because the pulmonary artery branches arise from the main
pulmonary artery trunk, an enlarged pulmonary artery will
have branches that arise from its lateral margin, and its vessels
will appear to converge toward the main pulmonary artery
[32]. Option B is the best response. A true hilar mass may have
the appearance of an enlarged pulmonary artery, but the vessels will not arise from its lateral margin but rather seem to
pass through the margin as they converge on the true pulmonary artery [32]. Therefore, if the convergence of the pulmonary arteries appears behind the apparent hilar mass or appears to arise from the heart, a mediastinal mass is more likely
[32]. Options A, C, and D are not the best responses.
Scenario 5
pleural effusion or interstitial edema is present. A contrast-enhanced coronal maximum-intensity-projection
chest CT scan (Fig. 5C) shows separation of the visceral
and parietal pericardial layers by a large fluid collection
surrounding the myocardium.
Clinical History
A 47-year-old man presented with chronic renal failure
and dyspnea (Fig. 5).
Description of Images
A posteroanterior chest radiograph (Fig. 5A) shows
globular enlargement of the cardiomediastinal silhouette. There is an increase in transverse diameter of the
cardiomediastinal silhouette but no increase in its height.
The proximal segments of the visible left and right pulmonary artery lie laterally to the cardiac silhouette. A
coned-down lateral chest radiograph (Fig. 5B) reveals
separation of the black retrosternal fat stripe from the
black epicardial fat stripe by an opaque interface. No
Question 7
What is the MOST LIKELY diagnosis?
A.
B.
C.
D.
E.
S10
Lobar pneumonia.
Primary lung cancer.
Acute heart failure.
Anterior mediastinal mass.
Pericardial effusion.
Treatment
The treatment, which was unsuccessful, was surgical debulking of the tumor and palliative radiotherapy. The patient died over the next several weeks.
Diagnosis
The diagnosis is uremic pericardial effusion, the water
bottle sign.
Solution to Question 7
A frontal chest radiograph (Fig. 5A) shows globular enlargement of the cardiomediastinal silhouette with an increase in its transverse diameter but no increase in its height.
As a result, the superior mediastinal borders appear straightened, giving the cardiomediastinal silhouette a morphology
that has been likened to that of a water bottle, hence the
designation “water bottle sign” [37, 38]. Applying the hilum overlay sign discussed in scenario 4, the proximal segment of the visible left and right pulmonary artery continues to lie laterally to the enlarged cardiac silhouette (i.e.,
negative hilum overlay), thus eliminating anterior mediastinal mass from diagnostic consideration. Option D is not the
best response.
The pericardium consists of two layers. The visceral pericardium is attached to the surface of the myocardium and
the proximal great vessels. The parietal pericardium forms
the free wall of the pericardial sac [37–40]. The pericardial
AJR:192, March 2009
Thoracic Imaging
A
B
Fig. 5—47-year-old man with chronic renal failure and dyspnea.
A, Posteroanterior chest radiograph shows globular enlargement of
cardiomediastinal silhouette. Note increase in transverse diameter of
cardiomediastinal silhouette but no increase in its height. Proximal segment of
visible left and right pulmonary artery lies lateral to cardiac silhouette.
B, Coned-down lateral chest radiograph reveals separation of black retrosternal
fat stripe (single arrow) from black epicardial fat stripe (double arrows) by
opaque interface. No pleural effusion or interstitial edema is present.
C, Contrast-enhanced coronal maximum-intensity-projection chest CT scan at
mediastinal window setting shows separation of visceral and parietal
pericardial layers by large fluid collection surrounding myocardium.
C
sac itself normally contains 20–50 mL of fluid [37]. An excess of pericardial fluid may accumulate in a number of settings. Option E is the best response. The most common cause
is myocardial infarction with left ventricular failure [37].
Fifty percent of patients with chronic renal failure develop
uremic pericardial effusions [37]. Other causes of pericardial effusion may include hypoalbuminemia, myxedema,
infection, drug reactions, trauma, neoplasia, and autoimmune disease [37]. The chest radiograph may appear relatively normal until the volume of pericardial fluid exceeds
AJR:192, March 2009
250 mL [37–39]. The cardiomediastinal silhouette may then
show symmetric enlargement and preservation of the normal hilar relationships, resulting in the water bottle–shaped
morphology [37–39] (Fig. 5A). A well-penetrating lateral
chest radiograph is even more sensitive in the early detection of pericardial effusion and may reveal separation of
the retrosternal and epicardial fat stripe by more than 2
mm, which is sometimes referred to as the “Oreo [Nabisco]
cookie sign,” “sandwich sign,” or “bun sign” [37–39] (Fig.
5B). The black epicardial and retrosternal fat stripes consti-
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Parker et al.
tute the outer dark cookie layers or slices of bread in the
sandwich or bun, and the opaque intervening pericardial
fluid, the white fluff of the cookie or the meat in the sandwich or bun. Although the cardiac silhouette is enlarged,
the pulmonary vasculature appears normal, and signs of
heart failure (e.g., vascular redistribution, Kerley B lines,
and so forth) are absent (Fig. 5A). Option C is not the best
response. CT is more sensitive in the detection of small pericardial effusions. Small effusions first collect dorsally to the
left ventricle and along the left atrium. Larger effusions collect ventrally and laterally to the right ventricle. Very large
effusions may envelop the myocardium, forming the “halo
sign” [37, 40] (Fig. 5C). Lobar pneumonia and primary lung
cancer are both air-space disease processes and are not ap-
propriate considerations in this patient. Options A and B
are not the best responses.
Uremic pericardial effusion commonly improves with intensified or increased frequency of peritoneal or hemodialysis
[41]. More aggressive management may be needed if the pericardial effusion is larger than 250 mL, if it continues to increase despite intensive dialysis for 10–14 days, or if the patient develops tamponade [41, 42]. In these latter instances,
pericardiocentesis, pericardial window, subxiphoid pericardiotomy, or pericardiectomy may be necessary [41, 42].
Scenario 6
Description of Images
A posteroanterior chest radiograph (Fig. 6A) shows an increased cardiothoracic ratio. The pulmonary artery segment
is enlarged, suggesting precapillary pulmonary hypertension.
The aorta appears small from decreased forward cardiac out-
put. A convex bulge is present along the left heart border related to left atrial chamber enlargement. Midline median sternotomy wires can be delineated. A lateral chest radiograph
(Fig. 6B) reveals a convex bulge in the superoposterior cardiac
border below the carina, with posterior displacement of the
left lower lobe bronchus and opacification of the retrocardiac
clear space. Right ventricular enlargement encroaches on the
retrosternal clear space. Foci of residual pneumomediastinum
and a retained subxiphoid pacer lead can be seen in the retro­
sternum. A newly placed mitral valve prosthesis is present.
Thin curvilinear calcifications can also be seen paralleling the
A
B
Clinical History
A 62-year-old woman presented with a long-standing history of chronic atrial fibrillation; she had undergone cardiac
surgery 7 days earlier (Fig. 6).
Treatment
The patient was successfully treated with a combination
of increased hemodialysis and subxiphoid pericardiotomy.
Fig. 6—62-year-old woman with long-standing history of chronic atrial fibrillation. Patient had undergone cardiac surgery 7 days earlier.
A, Posteroanterior chest radiograph shows increased cardiothoracic ratio. Pulmonary artery segment is enlarged, suggesting precapillary pulmonary hypertension. Aorta appears small from decreased forward cardiac output. Convex bulge is present along left heart border related to left atrial chamber enlargement.
Midline median sternotomy wires can be delineated.
B, Lateral chest radiograph shows relative posterior displacement of left upper and lower lobe bronchus relative to right (arrows), forming “walking man sign.”
Right ventricular enlargement encroaches on retrosternal clear space. Foci of residual pneumomediastinum and retained subxiphoid pacer lead can be seen in
retrosternum. Newly placed mitral valve prosthesis is present. Thin curvilinear calcifications can also be seen paralleling posterior wall of enlarged left atrium. No
radiographic evidence of acute cardiac decompensation is seen.
S12
AJR:192, March 2009
Thoracic Imaging
Question 8
What is the MOST LIKELY diagnosis?
A.
B.
C.
D.
Acute heart failure.
Ebstein anomaly.
Mitral stenosis.
Mitral valve prolapse.
Question 9
Which imaging sign is demonstrated on the lateral
chest radiograph (Fig. 6B)?
A.
B.
C.
D.
Coeur en sabot sign.
Walking man sign.
Double density sign.
Doughnut sign.
Question 10
What is the principal cause of acquired mitral
stenosis?
A.
B.
C.
D.
Rheumatic heart disease.
Left atrial myxoma.
Left atrial thrombus.
Maternal ingestion of lithium in the first trimester
of pregnancy.
posterior wall of the enlarged left atrium. No radiographic
evidence of acute cardiac decompensation is seen.
Diagnosis
The diagnosis is mitral stenosis and left atrial calcification, as indicated by the walking man sign.
Solution to Question 8
Although the cardiothoracic ratio is enlarged, the vascular
pedicle is not widened and there is no radiographic evidence
of vascular redistribution or septal lines to support a diagnosis of acute heart failure (Fig. 6). Option A is not the best
response. Ebstein anomaly is a congenital heart malformation manifested by apical displacement of the septal and posterior tricuspid valve leaflets, leading to atrialization of the
right ventricle and a variable degree of malformation and
displacement of the anterior leaflet [43]. Although chest radiography may be normal in patients with Ebstein anomaly,
characteristic radiologic features include right atrial enlargement, which may occasionally be quite severe; inferior vena
cava and azygos dilatation secondary to tricuspid regurgitation; hypoplasia of the aorta and main pulmonary artery;
and a normal-sized left atrium [44]. These radiographic features are not present in this patient (Fig. 6). Option B is not
the best response. Although mitral valve prolapse may be as-
AJR:192, March 2009
sociated with cardiac dysrhythmias, enlargement of the left
atrium (Fig. 6) is uncommon except in cases of prolapse complicated by severe mitral regurgitation [45, 46]. Option D is
not the best response.
Mitral stenosis is characterized by narrowing of the inlet
valve orifice of the left ventricular chamber, which interferes
with normal opening during diastole [37, 47–49]. Option C is
the best response. Affected patients typically have thickened
valve leaflets, fused commissures, or thickened and shortened
chordae tendineae. The normal mitral valve orifice area is 4–6
cm2 [47–49]. In early diastole, a small pressure gradient exists
between the atrium and the ventricle, but during most of diastole the pressures in these two chambers are relatively similar. When the mitral valve area narrows to less than 2.5 cm2,
blood flow is impeded, which causes an increase in left atrial
pressure. Critical mitral stenosis occurs when the area is reduced to 1 cm2 [47–49]. When this occurs, a left atrial pressure
of at least 25 mm Hg is necessary to maintain normal cardiac
output [47–49]. The increase in left atrial pressure enlarges
the left atrium and increases pulmonary venous and capillary
pressures, resulting in pulmonary venous congestion and reduced cardiac output. This scenario can mimic left ventricular
failure, but left ventricular contractility is usually normal.
Chronic atrial fibrillation commonly ensues as the left atrium
enlarges [50]. Chronic elevation of left atrial pressures leads to
pulmonary artery hypertension, tricuspid and pulmonary
valve incompetence, right ventricular hypertrophy (Fig. 6)
and, eventually, right heart failure [37, 47–49]. In cases of
long-standing mitral stenosis, the left atrial wall may rarely
calcify (Fig. 6B). Such calcification is more common in patients with endocarditis resulting from rheumatic heart disease; most affected patients also have heart failure and chronic atrial fibrillation [51]. Calcification of the mitral valve itself
occurs in approximately 10% of affected patients. This should
not be confused with mitral annulus calcification. Calcification of the mitral valve annulus does not indicate underlying
mitral stenosis and is often a finding of senescence [37, 49].
Solution to Question 9
The term “coeur en sabot” refers to a heart that has a bootshaped morphology as a result of uplifting of the cardiac
apex because of right ventricular hypertrophy and the absence of a normal main pulmonary artery segment [44]. This
is a feature on frontal chest radiographs most often associated
with tetralogy of Fallot. Additional radiologic features of this
congenital cardiac malformation include decreased pulmonary vascularity; a normal-sized heart because of the lack of
pulmonary blood flow and heart failure; right atrial enlargement; and, in approximately 20–25% of affected patients, a
right-sided aortic arch [44]. Option A is not the best response.
The “double density sign” is an early radiologic feature of left
atrial enlargement seen on frontal, not lateral, chest radiographs [52]. Option C is not the best response. This imaging
sign manifests as an interface projecting over the right retro-
S13
Parker et al.
cardiac region (Fig. 6A). The interface represents the inferior
margin of the enlarged left atrium as it pushes into the adjacent lung [52]. On frontal radiographs of adult patients, a left
atrial dimension—defined as the distance from the midpoint
of the double density to the inner margin of the left mainstem bronchus—greater than 7 cm suggests left atrial enlargement is present [52]. However, this sign and these dimensions are not reliable in pediatric patients [52]. The double
density sign is often associated with splaying of the normal
carinal angle of 60–90° and divergence of the caudal mainstem bronchi, creating a somewhat “wishbone” morphology
in severe cases [52]. These latter two signs are best appreciated on well-exposed or well-penetrating frontal examinations.
The “doughnut sign” is an imaging sign seen on lateral chest
radiography; however, it suggests the presence of mediastinal
lymphadenopathy, not cardiac valvular disease [53, 54]. Option D is not the best response. On normal chest radiography,
the aortic arch and the right and left pulmonary arteries create an inverted horseshoe appearance [53, 54]. Subcarinal
lymphadenopathy obliterates the notch in the horseshoe,
forming a rounded circle likened to the morphology of a bagel
or doughnut [53, 54].
The normal trachea, right and left upper lobe bronchi, and
lower lobe bronchi are vertically aligned on a normal lateral
chest radiograph. The walking man sign is a lateral chest radiography sign that is seen with posterior displacement of the
left upper or lower lobe bronchus relative to the right bronchi,
so that the bronchial relationship resembles the legs of a man
in midstride [55]. Option B is the best response. Posterior displacement of the left bronchi is typically the result of mass
effect on the bronchi by a markedly enlarged left atrium but is
not pathognomic of an enlarged atrium [55]. The walking man
sign may also occur in the setting of subcarinal lymphadenopathy, mediastinal masses, left lower lobe volume loss, large hiatal hernias, and thoracolumbar scoliosis.
Solution to Question 10
Although it is rare today, mitral stenosis is still most commonly caused by rheumatic fever [5–8]. Option A is the best
response. Approximately 40% of patients with rheumatic
heart disease have isolated mitral valve stenosis. However,
rheumatic involvement is identified in 99% of stenotic mitral
valves examined at the time of valve surgery [47–49]. Other,
less frequent, causes of mitral stenosis include congenital
stenosis, an obstructing lesion such as a left atrial myxoma,
atrial thrombus, systemic lupus erythematosus, rheumatoid
arthritis, malignant carcinoid, various mucopolysaccharidoses, Fabry’s disease, Whipple’s disease, and methysergide therapy [37, 47–49]. Options B and C are not the best responses.
Although it is somewhat controversial, maternal ingestion of
lithium, ingestion of benzodiazepines, and exposure to various
varnishing agents in the first trimester of pregnancy have been
reported to be associated risk factors for Ebstein anomaly [56,
57]. Option D is not the best response.
S14
Balloon valvotomy is usually the initial procedure of choice
for symptomatic patients with moderate to severe mitral
stenosis. Valvotomy can double the mean valve area, with a
50–60% decrease in the transmitral gradient, which provides
symptomatic improvement. Surgical commissurotomy has a
similar efficacy to that of balloon valvotomy but is usually
reserved for patients with left atrial thrombus despite anticoagulation or a nonpliable or calcified valve. Mitral valve replacement is reserved for patients who are not candidates for
either percutaneous balloon mitral valvotomy or surgical
commissurotomy [58, 59]. Lifelong endocarditis antibiotic
prophylaxis is recommended for procedures that may be associated with transient bacteremia (e.g., dental procedures,
bronchoscopy, colonoscopy, cystoscopy, and so forth) [58–60].
Treatment
The treatment is mitral valve replacement. The patient
was discharged on postoperative day 7. We have no additional information on her current clinical status.
Conclusion
This case-based self-assessment module describes several
important radiologic signs that are useful in diagnosing various diseases affecting the chest, including the luftsichel sign of
left upper lobe collapse; the incomplete border sign of pleural
and chest wall-based lesions; the head cheese sign or hog’s head
cheese sign of atypical infection with associated bronchiolitis,
sarcoidosis, acute interstitial pneumonitis, and hypersensitivity pneumonitis; the hilum overlay sign, which is useful in localizing lesions to the anterior mediastinum; the hilum convergence sign that distinguishes an enlarged pulmonary artery
from a true hilar mass; the water bottle sign and the Oreo
cookie sign of pericardial effusion; and the walking man sign
of left atrial enlargement. Future articles will continue this
discussion of additional useful signs in thoracic imaging that
can be applied to assist the radiologist in establishing the correct diagnosis or differential diagnosis in applicable cases.
References
1.Ely EW, Haponik EF. Using the chest radiograph to determine intravascular
volume status: the role of vascular pedicle width. Chest 2002; 121:942–950
2.Martin GS, Ely EW, Carroll FE, Bernard GR. Findings on the portable chest
radiograph correlate with fluid balance in critically ill patients. Chest 2002;
122:2087–2095
3.Bruns AH, Oosterheert JJ, Prokop M, Lammers JW, Hak E, Hoepelman AI.
Patterns of resolution of chest radiograph abnormalities in adults hospitalized
with severe community-acquired pneumonia. Clin Infect Dis 2007; 45:983–991.
[Epub 2007 Sep 12]
4.Vilar J, Domingo ML, Soto C, Cogollos J. Radiology of bacterial pneumonia.
Eur J Radiol 2004; 51:102–113
5.Blankenbaker DG. The luftsichel sign. Radiology 1998; 208:319–320
6.Fraser RS, Müller NL, Colman N, Pare PD. Atelectasis. In: Fraser and Pare’s
diagnosis of diseases of the chest, 4th ed. Philadelphia, PA: Saunders,
1999:529–532
7.Isbell D, Grinnan D, Patel MR. Luftsichel sign in upper lobe collapse. Am J
Med 2002; 112:676–677
8.Woodring JH, Reed JC. Radiographic manifestations of lobar atelectasis. J
Thorac Imaging 1996; 11:109–144
AJR:192, March 2009
Thoracic Imaging
9.Knisely BL, Kuhlman JE. Radiographic and computed tomography (CT) imaging of complex pleural disease. Crit Rev Diagn Imaging 1997; 38:1–58
10.Qureshi NR, Gleeson FV. Imaging of pleural disease. Clin Chest Med 2006;
27:193–213
11.Aiken A, Gooding C. “Ex vacuo” pneumothorax. AJR 2003; 181:885
12.Rosado de Christenson ML, Abbott GF, Kirejczyk WM, Galvin JR, Travis
WD. Thoracic carcinoids: radiologic–pathologic correlation. RadioGraphics
1999; 19:707–736
13.Travis WD, Colby TV, Corrin B, et al. Histologic typing of lung and pleural
tumors: international histologic classification of tumours, 3rd ed. Berlin, Germany: Springer-Verlag, 1999
14.Parker MS, Rosado-de-Christenson ML, Abbott GF. Neoplastic disease. In:
Teaching atlas of chest imaging. New York, NY: Thieme Scientific & Medical
Publishers, 2006:337–340
15.Völk M, Strotzer M, Feuerbach S. Case of the month. Intrapulmonary or extrapulmonary? Br J Radiol 2000; 73:451–452
16.Catalano O. The incomplete border sign. Radiology 2002; 225:129–130
17.Ellis R. Incomplete border sign of extrapleural masses. JAMA 1977; 237:2748
18.Gladish GW, Sabloff BM, Munden RF, Truong MT, Erasmus EA, Chasen MH.
Primary thoracic sarcoma. RadioGraphics 2002; 22:621–637
19.Tateishi U, Gladish GW, Kusumoto M, et al. Chest wall tumors: radiologic
findings and pathologic correlation. Part 2. Malignant tumors. RadioGraphics
2003; 23:1491–1508
20.Parker MS, Rosado-de-Christenson ML, Abbott GF. Chest wall, pleura, and
diaphragm. In: Teaching atlas of chest imaging. New York, NY: Thieme Scientific & Medical Publishers, 2006:748–751
21.Haus BM, Stark P, Shofer SL, Kuschner WG. Massive pulmonary pseudotumor. Chest 2003; 124:758–760
22.Magdeleinat P, Alifano M, Petino A, et al. Solitary fibrous tumors of the pleura:
clinical characteristics, surgical treatment and outcome. Eur J Cardiothorac
Surg 2002; 21:1087–1093
23.Rosado-de-Christenson ML, Abbott GF, McAdams HP, Franks TJ, Galvin JR.
Localized fibrous tumors of the pleura. RadioGraphics 2003; 23:759–783
24.Lee SC, Tzao C, Ou SM, Hsu HH, Yu CP, Cheng YL. Solitary fibrous tumors
of the pleura: clinical, radiological, surgical and pathological evaluation. Eur J
Surg Oncol 2005; 31:84–87
25.Webb W, Müller N, Naidich D. High-resolution CT of the lung. New York, NY:
Lippincott-Raven, 2000:168–172
26.Chung M, Edinburgh K, Webb E, McCowin M, Webb W. Mixed infiltrative and
obstructive disease on high-resolution CT: differential diagnosis and functional
correlates in a consecutive series. J Thorac Imaging 2001; 16:69–75
27.Patel RA, Sellami D, Gotway MB, Golden JA, Webb WR. Hypersensitivity
pneumonitis: patterns on high-resolution CT. J Comput Assist Tomogr 2000;
24:965–970
28.Fraser RS, Müller NL, Colman N, Pare PD. Embolic lung disease: thrombosis
and thromboembolism. In: Fraser and Pare’s diagnosis of diseases of the chest,
4th ed. Philadelphia, PA: Saunders, 1999:1829–1832
29.Travis WD, Colby TV, Koss MN, Rosado de Christenson ML, Muller NL, King
TE Jr. Lung infections. In: King DW, ed. Atlas of nontumor pathology: nonneoplastic disorders of the lower respiratory tract, series 1, fasc. 2. Washington, DC: American Registry of Pathology, 2002:187–196
30.Parker MS, Rosado-de-Christenson ML, Abbott GF. Mycoplasma pneumonia.
In: Teaching atlas of chest imaging. New York, NY: Thieme Scientific & Medical Publishers, 2006:283–285
31.Miyashita N, Obase Y, Ouchi K, et al. Clinical features of severe Mycoplasma
pneumoniae pneumonia in adults admitted to an intensive care unit. J Med
Microbiol 2007; 56(Pt 12):1625–1629
32.Felson B. Localization of intrathoracic lesions. In: Chest roentgenology. Philadelphia, PA: Saunders, 1973:39–41
33.Whitten CR, Khan S, Munneke GJ, Grubnic S. A diagnostic approach to mediastinal abnormalities. RadioGraphics 2007; 27:657–671
34.Chao BH, Smith TJ. Intrathoracic malignant peripheral nerve sheath tumor in
neurofibromatosis 1. J Clin Oncol 2008; 26:2216–2218
AJR:192, March 2009
35.Ogino H, Hara M, Satake M, et al.. Malignant peripheral nerve sheath tumors
of intrathoracic vagus nerve. J Thorac Imaging 2001; 16:181–184
36.Besznyák I, Tóth L, Szende B. Intrathoracic vagus nerve tumors: a report of two
cases and review of the literature. J Thorac Cardiovasc Surg 1985; 89:462–465
37.Parker MS, Rosado-de-Christenson ML, Abbott GF. Adult cardiovascular disease. In: Teaching atlas of chest imaging. New York, NY: Thieme Scientific &
Medical Publishers, 2006:603–605
38.Carsky EW, Mauceri RA, Azimi F. The epicardial fat pad sign: analysis of
frontal and lateral chest radiographs in patients with pericardial effusion. Radiology 1980; 137:303–308
39.Woodring JH. The lateral chest radiograph in the detection of pericardial effusion: a reevaluation. J Ky Med Assoc 1998; 96:218–224
40.Lawler LP, Horton KM, Corl FM, Fishman EK. Review: the pericardium—a
computed tomography perspective. Crit Rev Diagn Imaging 2001; 42:229–258
41.Alpert MA, Ravenscraft MD. Pericardial involvement in end-stage renal disease. Am J Med Sci 2003; 325:228–236
42.Gunukula SR, Spodick DH. Pericardial disease in renal patients. Semin Nephrol 2001; 21:52–60
43.Paranon S, Acar P. Ebstein’s anomaly of the tricuspid valve: from fetus to
adult—congenital heart disease. Heart 2008; 94:237–243
44.Ferguson EC, Krishnamurthy R, Oldham SA. Classic imaging signs of congenital cardiovascular abnormalities. RadioGraphics 2007; 27:1323–1334
45.Babuty D, Casset-Senon D, Fauchier L, Giraudeau C, Fauchier JP, Cosnay P.
Mitral valve prolapse and cardiac arrhythmias. Card Electrophysiol Rev 2002;
6:129–131
46.Beasley B, Kerber R. Does mitral prolapse occur in mitral stenosis? Echocardiographic–angiographic observations. Chest 1981; 80:56–60
47.Bonow RO, Braunwald E. Valvular heart disease. In: Libby P, Bonow RO,
Mann DL, Zipes DP. Braunwald’s heart disease: a textbook of cardiovascular
medicine, 7th ed. Philadelphia, PA: Saunders, 2005:1553–1563
48.Del Negro AA. Physiology of mitral stenosis. In: Taveras JM, Ferrucci JT, eds.
Radiology on CD–ROM: diagnosis, imaging, intervention, vol. 2. Philadelphia,
PA: Lippincott Williams & Wilkins, 2000:CD-ROM, chapter 65
49.Edwards BS, Edwards JE. Pathology of mitral stenosis. In: Taveras JM, Ferrucci JT, eds. Radiology on CD–ROM: diagnosis, imaging, intervention, vol. 2.
Philadelphia, PA: Lippincott Williams & Wilkins, 2000:CD-ROM, chapter 64
50.Kim HK, Kim YJ, Shin JI, et al. Echocardiographic and hemodynamic findings
in patients with mitral stenosis undergoing percutaneous mitral commissurotomy comparing those with chronic atrial fibrillation versus those with normal
sinus rhythm. Am J Cardiol 2007; 100:1153–1160
51.Vijayvergiya R, Jeevan H, Grover A. Left atrial calcification in rheumatic heart
disease: a rare presentation. Heart 2006; 92:1218
52.Higgins CB, Reinke RT, Jones NE, et al. Left atrial dimension on frontal thoracic radiograph: a method for assessing left atrial enlargement. AJR 1978;
130:251–255
53.Roche CJ, O’Keefe DP, Lee WK, et al. Selections from the buffet of food signs
in radiology. RadioGraphics 2002; 22:1369–1384
54.Marshall GB, Farnquist BA, MacGregor JH, Burrowes PW. Signs in thoracic
imaging. J Thorac Imaging 2006; 21:76–89
55.Helms CA, Brant WE. Cardiac anatomy, physiology, and imaging modalities.
In: Fundamentals of diagnostic radiology, 3rd ed. Philadelphia, PA: Lippincott
Williams & Wilkins, 2006:611
56.Correa-Villaseñor A, Ferencz C, Neill CA, Wilson PD, Boughman JA. Ebstein’s
malformation of the tricuspid valve: genetic and environmental factors. The
Baltimore–Washington Infant Study Group. Teratology 1994; 50:137–147
57.Giles JJ, Bannigan JG. Teratogenic and developmental effects of lithium. Curr
Pharm Des 2006; 12:1531–1541
58.Carabello BA. What is new in the 2006 ACC/AHA guidelines on valvular heart
disease? Curr Cardiol Rep 2008; 10:85–90
59.Fedak PW, McCarthy PM, Bonow RO. Evolving concepts and technologies in
mitral valve repair. Circulation 2008; 117:963–974
60.Shipton B, Wahba H. Valvular heart disease: review and update. Am Fam Physician 2001; 63:2201–2208
S15
AJR Integrative Imaging
LIFELONG LEARNING
FOR RADIOLOGY
AJR Teaching File: Right Atrial Mass in a Woman with
Dyspnea on Exertion
Benjamin J. Holloway1, Prachi P. Agarwal2
Case History
A 50-year-old woman presents with nonspecific chest
pain, a syncopal episode, and increasing dyspnea on exertion without edema, orthopnea, or paroxysmal nocturnal
dyspnea. CT pulmonary angiography is performed to evaluate for pulmonary embolism. This is followed by cardiac
MRI to further evaluate abnormal cardiac findings identified on CT pulmonary angiography. CT of the abdomen
that was performed 7 months previously to investigate upper abdominal pain is also reviewed and found to include
the area of abnormality.
Radiologic Description
Initial contrast-enhanced abdominal CT shows subtle
thickening of the inferior right atrial wall near the diaphragm that was only appreciated in retrospect (Fig. 1A).
Subsequent CT pulmonary angiography performed 7
months later using 120 kVp, 150 mA, and 1.25-mm slice
thickness after the administration of 125 mL of the nonionic IV contrast material iopromide (Ultravist 300, Bayer
HealthCare) at 4 mL/s, reveals the dramatic rapid growth
of a large soft-tissue mass centered on the right atrial free
wall along with a right pleural effusion. The right lower lobe
lung nodule was one of several similar lesions in the lungs
(Fig. 1B). On cardiac MRI, the cine balanced steady-state
free precession (balanced SSFP) sequence (TR/TE, 2.9/0.99)
in four-chamber orientation shows a lobulated mass extending into and nearly obliterating the right atrial cavity but
without involvement of the interatrial septum (Fig. 1C and
video, Fig. S1C, in supplemental data at www.ajronline.
org). The mass is predominantly isointense on axial ECGgated breath-hold T1-weighted double inversion recovery
fast spin-echo sequence (667/41) with a few areas of scattered hyperintensity compatible with hemorrhage (Fig. 1D)
and has a heterogeneously hyperintense appearance on T2weighted images (1,364/101) (Fig. 1E). The mass extends
into the atrioventricular groove and encases the right coronary artery. On first-pass perfusion imaging with a gadolinium-based contrast agent (0.1 mmol kg of gadopentetate
dimeglumine), marked peripheral linear and nodular tumor
enhancement is evident (Fig. 1F and video, Fig. S1F, in supplemental data).
Differential Diagnosis
The differential diagnosis of a right atrial mass includes
benign entities such as myxoma and thrombus and malignant causes such as metastatic involvement of the heart,
primary cardiac angiosarcoma and other sarcomas, pericardial mesothelioma, and primary cardiac lymphoma.
Diagnosis
The diagnosis, based on biopsy of one of the lung metastases showing spindle cells, is primary cardiac angiosarcoma.
Commentary
Metastases are by far the most common cardiac neoplasms, 40 times more prevalent than primary cardiac tumors [1]. Primary cardiac tumors are rare lesions and include both benign and malignant histologic types, with
myxomas being the most common [2]. Primary malignant
cardiac tumors include angiosarcoma, undifferentiated sarcoma, rhabdomyosarcoma, osteosarcoma, leiomyosarcoma,
and primary cardiac lymphoma [1].
Angiosarcomas, although rare, are the most common primary malignant neoplasms of the heart, making up more
than a third of cardiac sarcomas [1, 3]. Cardiac angiosarcomas
present in adults around middle age, with cases in children and
infants being rare. Males are more commonly affected. The
clinical signs and symptoms are often nonspecific. Because of
the propensity of the tumor to involve the right atrium and
pericardium, patients may present with right-sided heart failure and tamponade [3, 4]. There is frequently metastatic
spread at presentation, most commonly to the lungs, but also
occasionally to lymph nodes, bone, liver, brain, bowel, spleen,
adrenal glands, pleura, diaphragm, kidneys, thyroid, and skin
[5]. The prognosis is universally poor; patients rarely survive
beyond a year despite treatment [6]. In most cases, angiosarcomas involve the right atrial free wall [7] as a well-defined
mass protruding into the right atrium and usually sparing the
interatrial septum. CT and MRI can both show tumor infiltra-
Keywords: cardiac imaging, heart neoplasm, MRI
DOI:10.2214/AJR.07.7066
Received December 27, 2007; accepted after revision April 7, 2008.
Department of Radiology, University Hospital Birmingham NHS Foundation Trust, Metchley La., Birmingham, West Midlands, B67 5HR, United Kingdom. Address correspondence
to B. J. Holloway ([email protected]).
1
2
Department of Radiology, Division of Cardiothoracic Radiology, University of Michigan, Ann Arbor, MI.
AJR 2009;192:SXX–SXX 0361–803X/09/1923–SX © American Roentgen Ray Society
S1
AJR:192, March 2009
Holloway and Agarwal
A
B
C
D
Fig. 1—50-year-old woman with shortness of breath and chest pain.
A, Axial contrast-enhanced CT scan of abdomen shows subtle thickening of inferior right atrial wall. d = dome of diaphragm.
B, Subsequent CT pulmonary angiography image 7 months later reveals dramatic growth of large lobulated mass centered on right atrial wall, new subpleural right
lower lobe lung nodule (arrow) that is one of many, and right pleural effusion. d = dome of diaphragm.
C, Four-chamber balanced steady-state free precession image shows lobulated mass extending into and nearly obliterating right atrial cavity but without involvement of interatrial septum. (See also supplemental video, Fig. S1C, at www.ajronline.org.)
D, Axial ECG-gated breath-hold T1-weighted double inversion recovery fast spin-echo image shows predominantly isointense mass with a few areas of scattered
hyperintensity compatible with hemorrhage.
(Fig. 1 continues on next page)
tion of the myocardium and direct extension into the pericardium [4]. The second, rarer subtype, is a diffusely infiltrative
mass extending along the pericardium [4].
Initial evaluation is usually performed using echocardiography, which may be limited by factors such as operator dependence, restricted field of view, and unfavorable body habitus. Cardiac MRI enables the most comprehensive imaging
assessment of cardiac neoplasms. In contrast to transthoracic
echocardiography, cardiac MRI provides improved soft-tissue
S2
contrast, tissue characterization, and assessment of mediastinal and lung involvement by the tumor. The addition of imaging with a gadolinium-based contrast agent allows an assessment of the extent of tumor vascularity and further improves
the differentiation from surrounding structures.
Angiosarcomas appear as irregular lobulated low-attenuation masses on CT that frequently extend to involve the adjacent pericardium and vessels. On MRI, they exhibit heterogeneous signal on T1- and T2-weighted sequences, which is
AJR:192, March 2009
Right Atrial Mass
E
F
Fig. 1 (continued)—50-year-old woman with shortness of breath and chest pain.
E, Heterogeneous hyperintense appearance is seen on axial ECG-gated breath-hold T2-weighted double inversion recovery fast spin-echo image.
F, First-pass perfusion image using fast gradient-echo echo-train pulse sequence shows marked peripheral linear and nodular enhancement. (See also supplemental video, Fig. S1F, at www.ajronline.org.)
thought to relate to hemorrhage, necrosis, and flow voids in
the tumor. These areas of high signal intensity interspersed
with areas of intermediate signal have been described as a
cauliflower appearance [8]. After administration of the gadolinium-based contrast agent, the tumor enhances heterogeneously and shows marked surface enhancement [1]. A sunray appearance has also been described in cases with diffuse
pericardial enhancement as multiple lines emanating from
the epicardium to pericardium [9].
In our patient, a benign neoplasm—the most common
being a myxoma—or a nonneoplastic lesion such as thrombus are unlikely in view of the infiltrative nature of the
mass and the development of multiple new lung nodules,
which are consistent with metastases. Also, the marked peripheral enhancement on the first-pass imaging is in keeping with a highly vascularized tumor. Although heterogeneous signal characteristics are common to both myxomas
and angiosarcomas, the former are generally more well-defined, often with a stalk; tend to involve the interatrial septum; and are more common in the left atrium [10].
The most common malignant cardiac tumor is cardiac metastasis, which can result from direct extension, hematogenous or venous extension, or retrograde flow by lymphatic
vessels. However, these manifest in patients with known noncardiac primary malignancy and widespread systemic disease. The most common malignancies metastatic to the heart
are lung and breast cancers, lymphoma, and leukemia, with
the pericardium rather than the myocardium being the most
common site of involvement. Only about 5% of metastases
are estimated to be endocardial or intracavitary lesions [5].
Differentiating angiosarcoma from other primary malignant cardiac neoplasms can be challenging. Angiosarcoma is
AJR:192, March 2009
statistically the most common primary malignant tumor and
arises most commonly in the right atrial free wall. Most other
cardiac sarcomas, such as undifferentiated sarcoma, leiomyosarcoma, and fibrosarcoma, have a propensity to involve the
left atrium, an important differentiating feature [5]. Rhabdomyosarcoma, the most common primary cardiac tumor in
children, does not have any chamber predilection [4].
Cardiac lymphoma is far more commonly seen as secondary
myocardial involvement related to extensive systemic disease.
Primary cardiac lymphoma—the absence of extracardiac disease at the time of diagnosis—is rare [5]. The primary form
usually occurs in immunocompromised individuals and favors
the right heart, as does angiosarcoma. However, lymphoma is
less likely to involve cardiac valves, show necrosis, or extend
into the cardiac chamber than angiosarcoma [11].
Pericardial mesothelioma is thought to be a distinct entity and not an extension of pleural mesotheliomas into the
pericardium [5]. Pericardial mesothelioma encases the heart
and resembles metastatic involvement of the pericardium
[5]. Frank invasion of the epicardium is rarely seen [1].
Objective
The educational objective of this article is to describe the
MRI features of cardiac angiosarcoma and to highlight the
features differentiating it from other cardiac masses.
Conclusion
Cardiac angiosarcomas, although rare, are the most common primary malignant cardiac tumors. The location of
the tumor on the right atrial wall, its heterogeneous infiltrative appearance, and its enhancement are important diagnostic features. The tumor is aggressive, and metastases to
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Holloway and Agarwal
the lungs are frequently discovered at presentation. The
long-term prognosis is universally poor.
References
1.Sparrow PJ, Kurian JB, Jones TR, Sivananthan MU. MR imaging of cardiac
tumors. RadioGraphics 2005; 25:1255–1276
2.Reynen K. Frequency of primary tumors of the heart. Am J Cardiol 1996; 77:107
3.Burke A, Virmani R. Tumors of the heart and great vessels. In: Atlas of tumor
pathology, fasc 16, ser 3. Washington, DC: Armed Forces Institute of Pathology, 1996
4.Araoz PA, Eklund HE, Welch TJ, Breen JF. CT and MR imaging of primary
cardiac malignancies. RadioGraphics 1999;19:1421–1434
5.Grebenc ML, Rosado de Christenson ML, Burke AP, Green CE, Galvin JR.
Primary cardiac and pericardial neoplasms: radiologic–pathologic correlation.
RadioGraphics 2000; 20:1073–1103
6.Burke AP, Cowan D, Virmani R. Primary sarcomas of the heart. Cancer 1992;
69:387–395
7.Best AK, Dobson RL, Ahmad AR. Best cases from the AFIP: cardiac angiosarcoma. RadioGraphics 2003; 23[spec no]:S141–S145
8.Kim EE, Wallace S, Abello R, et al. Malignant cardiac fibrous histiocytomas
and angiosarcomas: MR features. J Comput Assist Tomogr 1989; 13:627–632
9.Yahata S, Endo T, Honma H, et al. Sunray appearance on enhanced magnetic
resonance image of cardiac angiosarcoma with pericardial obliteration. Am
Heart J 1994; 127:468–471
10.Grebenc ML, Rosado-de-Christenson ML, Green CE, Burke AP, Galvin JR.
Cardiac myxoma: imaging features in 83 patients. RadioGraphics 2002;
22:673–689
11.Luna A, Ribes R, Caro P, Vida J, Erasmus JJ. Evaluation of cardiac tumors with
magnetic resonance imaging. Eur Radiol 2005; 15:1446–1455
F O R YO U R I N F O R M AT I O N
A data supplement for this article can be viewed in the online version of the article at: www.ajronline.org.
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AJR:192, March 2009
AJR Integrative Imaging
LIFELONG LEARNING
FOR RADIOLOGY
AJR Teaching File:
Right Atrial Mass in a Woman with Uterine Fibroids
Samah Jan1, Evan H. Dillon, Neal F. Epstein
Case History
A 48-year-old woman with a history of hypertension who
had undergone dilatation and curettage for vaginal bleeding
related to uterine fibroids presents with palpitations and
chest pain. A heart murmur is detected on physical examination. Echocardiography performed elsewhere depicted a
possible right atrial myxoma with inferior vena caval involvement. She was then referred to our institution for further evaluation and treatment.
Radiologic Description
CT of the abdomen and pelvis was requested to assess the
degree of inferior vena caval obstruction produced by the
right atrial mass detected on the echocardiogram. Images
were obtained before and after the administration of intravenous contrast material. Axial and coronal reformatted
images were produced. The unenhanced images depicted no
visible abnormality in the right atrium or inferior vena
cava. The contrast-enhanced images depicted a continuous
tubular filling defect projecting within the lumen of the
right atrium and within the lumen of the inferior vena cava
and extending inferiorly to the level of the confluence of
the iliac veins (Figs. 1A–1C). No definite iliac vein involvement was depicted. The tubular filling defect had a visualized length of 20.8 cm and a transverse diameter of 0.5 cm.
It appeared to have a small central focus of enhancement.
Images of the pelvis showed the uterus to be markedly enlarged and extending superiorly to the level of the L4 vertebral body (Figs. 1D and 1E). Multiple focal heterogeneous
myometrial lesions were identified with an appearance consistent with uterine leiomyomas.
MRI of the heart was performed to provide further assessment of the right atrial mass seen on the echocardiogram.
Images were obtained in multiple planes both with and without gadolinium. These images confirm the presence of a tubular filling defect extending into the right atrium from the
inferior vena cava (Figs. 1F and 1G). The abnormality was
best visualized on the cine MR images using a white blood
steady-state free precession (SSFP) pulse sequence (FIESTA
[GE Healthcare]: fast imaging employing steady-state acquisition sequence on a GE Healthcare Signa 1.5-T MRI scan-
ner) without gadolinium. These cine images revealed that the
filling defect was not attached to the wall of the right atrium
or inferior vena cava. Instead, it was shown to move freely
within the lumen of the right atrium and within the lumen
of the inferior vena cava on images obtained during different
phases of the cardiac cycle. During diastole, the mass appeared to prolapse across the tricuspid valve (Figs. 1H and
1I). MRI confirmed the central focus of flow in the center of
the tubular structure (Fig. 1F).
An inferior vena cavagram was obtained using a right
common iliac vein injection followed by a left common iliac
vein injection. These images showed a long mobile filling
defect extending from the left internal iliac vein into the left
common iliac vein and up the length of the inferior vena
cava (Fig. 1J).
Differential Diagnosis
An apparent filling defect in the inferior vena cava extending into the right atrium may be artifactual or actual
[1, 2]. The most common artifactual filling defect is pseudothrombosis produced by an admixture of opacified and unopacified blood. Actual filling defects include bland thrombus and tumor thrombus. Bland thrombus may be
idiopathic or may result from a hypercoagulable state. Tumor thrombus is most commonly seen with malignant tumors, including renal and hepatic tumors, that extend into
the inferior vena cava but may also be seen with benign tumors, including intravenous leiomyomatosis, renal angiomyolipoma, and adrenal pheochromocytoma.
Diagnosis
The diagnosis is tumor thrombus due to intravenous leiomyomatosis with angioid features extending from uterine
leiomyomata. This patient first underwent an open resection
of the intracardiac and intravascular portions of the tumor
through a right atrial approach. The pathology specimen
from that surgery revealed intravenous leiomyomatosis. Subsequently, the patient underwent a supracervical hysterectomy and bilateral salpingo-oophorectomy. The pathology
specimen from that surgery revealed extensive uterine leiomyomatosis as well as intravenous leiomyomatosis with focal
vascular thrombosis. The cut surfaces of the myometrium
Keywords: cine MRI, CT, heart, MRI, uterine fibroids, vascular system, venography, women’s imaging
DOI:10.2214/AJR.07.7080
Received February 28, 2008; accepted after revision April 7, 2008.
1
All authors: Department of Radiology, Lenox Hill Hospital, 100 E 77th St., New York, NY 10075. Address correspondence to E. H. Dillon ([email protected]).
AJR 2009;192:SXX–SXX 0361–803X/09/1923–SX © American Roentgen Ray Society
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AJR:192, March 2009
Jan et al.
A
B
Fig. 1—48-year-old woman with palpitations, chest pain, heart murmur, and
right atrial mass seen on echocardiography.
A and B, Axial contrast-enhanced CT scans at level of suprahepatic (A) and
suprarenal (B) portions of inferior vena cava show filling defect in inferior vena
cava with central enhancement (arrows).
C, Coronal contrast-enhanced CT scan shows thin linear filling defect (arrows)
extending throughout length of inferior vena cava.
(Fig. 1 continues on next page)
C
revealed branching vascular spaces filled with gelatinous material and wormlike structures. Immunohistochemical stains
showed strong diffuse labeling in tumor cell nuclei for progesterone receptor and smooth muscle actin, whereas staining
for estrogen receptor was weak and focal.
Commentary
Intravenous leiomyomatosis is a rare benign tumor characterized by proliferation of smooth muscle cells in the
veins [3, 4]. The tumor may arise directly from the wall of
the vein but more commonly occurs as a result of growth of
uterine leiomyomata into the myometrial veins [5]. From
the myometrial veins, intravenous leiomyomatosis may
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spread to the pelvic veins, inferior vena cava, right atrium,
right ventricle, and pulmonary artery [4–6]. Involvement
of the adrenal and renal veins has also been reported [5].
Intravenous leiomyomatosis is one of the unusual
growth patterns of histologically benign uterine leiomyomata [4]. Other unusual growth patterns of uterine leiomyomata include parasitic leiomyoma, disseminated peritoneal leiomyomatosis, diffuse leiomyomatosis, and benign
metastasizing leiomyoma. Although they are histologically benign, these aggressive growth patterns resemble the
behavior of malignant tumors.
Intravenous leiomyomatosis is seen almost exclusively in
white women in the age range of 28–80 years (median age,
AJR:192, March 2009
Right Atrial Mass
D
E
F
G
Fig. 1 (continued)—48-year-old woman with palpitations, chest pain, heart murmur, and right atrial mass seen on echocardiography.
D and E, Axial (D) and coronal (E) contrast-enhanced CT scans of mid pelvis show uterus to be markedly enlarged, lobulated, and heterogeneous, an appearance that
likely represents presence of multiple uterine leiomyomas.
F, Oblique axial cine MR image at level of suprahepatic portion of inferior vena cava (IVC) using white blood steady-state free precession (SSFP) pulse sequence
(FIESTA [GE Healthcare]: fast imaging employing steady-state acquisition sequence) without gadolinium shows filling defect (arrow) in inferior vena cava with central flow.
G, Oblique sagittal cine MR image of heart and intrahepatic portion of IVC using white blood SSFP pulse sequence (FIESTA) without gadolinium shows filling defect
(arrows) extending from inferior vena cava into right atrium.
(Fig. 1 continues on next page)
AJR:192, March 2009
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Jan et al.
H
I
Fig. 1 (continued)—48-year-old woman with palpitations, chest pain, heart
murmur, and right atrial mass seen on echocardiography.
H, Axial cine MR image at level of right atrium using white blood SSFP pulse
sequence (FIESTA) without gadolinium shows filling defect (arrow) along right
lateral wall of right atrium during systole.
I, Axial cine MR image at level of right atrium using white blood SSFP pulse sequence (FIESTA) without gadolinium shows filling defect (arrow) prolapsing
across tricuspid valve during diastole.
J, Inferior vena cavagram obtained using left common iliac vein injection shows
linear filling defect (arrows) extending from left internal iliac vein into left common iliac vein and up into inferior vena cava.
J
44 years). It typically occurs in parous women before menopause [5, 7]. Most patients with intravenous leiomyomatosis have a history of uterine leiomyoma leading to hysterectomy, often many years earlier [5, 7]. Patients with intra­venous
leiomyomatosis may present with symptoms related to
uterine leiomyomata, such as pelvic pain or vaginal bleeding [5]. They may also present with symptoms of inferior
vena cava obstruction such as lower extremity edema. If
the tumor extends into the heart, the patient may present
with heart failure, dyspnea on exertion, pulmonary embolism, syncope, or sudden death [5, 7]. Physical examination
S4
may reveal a heart murmur related to partial obstruction
of the tricuspid valve [7].
The first imaging study is often echocardiography to evaluate a heart murmur. On echocardiography, a mass may be
visible in the right atrium, as occurred in our patient. Careful
inspection will reveal that the mass extends into the right
atrium from the inferior vena cava. Subsequent studies often
include CT and MRI. On contrast-enhanced CT and MRI, an
enhancing mobile intraluminal filling defect is usually depicted. Establishing the diagnosis on CT or MRI depends on visualizing the connection between the intravenous mass and
AJR:192, March 2009
Right Atrial Mass
the uterus [5]. However, in most patients who have previously undergone hysterectomy, that connection cannot be
shown. If the previous hysterectomy specimen showed a
pathologic diagnosis of intravenous leiomyomatosis, then it
is likely that a subsequently visualized intravenous mass represents recurrence and spread of intravenous leiomyomatosis. The differential diagnosis of intravenous leiomyomatosis
includes other causes of tumor thrombus such as renal cell
carcinoma, hepatocellular carcinoma, adrenocortical carcinoma, pancreatic carcinoma, Wilms’ tumor, renal angiomyolipoma, and adrenal pheochromocytoma [1, 5].
Treatment consists of complete surgical excision of the intravenous tumor along with hysterectomy and bilateral oophorectomy [5]. Surgery can be performed as a two-stage operation with separate resections of the intracardiac tumor and
the abdominopelvic tumor, or as a one-stage operation with
total resection of the entire tumor [7]. The recurrence rate after resection is 30%. Therefore, surveillance imaging every few
months may be useful to assess for recurrent disease [5, 7].
Objective
The educational objective of this article is to describe the
imaging findings and clinical characteristics of intravenous
leiomyomatosis.
ine tumors grow into and extend up the draining veins. When
an inferior vena caval or right atrial mass is discovered in a
woman with a history of hysterectomy for uterine leiomyomata or who currently has uterine leiomyomata, the possibility of intravenous leiomyomatosis should be considered. Imaging should be directed toward assessing the full extent of
the tumor and showing the connection between the intravenous tumor and the leiomyomatous uterus.
References
1. Kaufman LB, Yueh BM, Bierman RS, Joe BN, Hayem A, Coakley FV. Inferior
vena cava filling defects on CT and MRI. AJR 2005; 185:717–726
2. Sheath S, Fishman EK. Imaging of the inferior vena cava with MDCT. AJR
2007; 189:1243–1251
3. Ueda H, Togashi K, Konica I, et al. Unusual appearances of uterine leiomyomas: MR imaging findings and their histopathologic backgrounds. RadioGraphics 1999; 19[spec no]:S131–S145
4. Cohen DT, Oliva E, Hahn PF, Fuller AF Jr, Lee SI. Uterine smooth-muscle tumors with unusual growth patterns: imaging with pathologic correlation. AJR
2007; 188:246–255
5. Ahmed M, Zangos S, Reichstein WO, Vogel TJ. Tips and tricks: intravenous
leiomyomatosis. Eur Radiol 2004; 14:1316–1317
6. Vari G, Carazzi S, Bussichella F, et al. Intravenous leiomyomatosis extending
from the inferior caval vein to the pulmonary artery. J Thorac Cardiovasc Surg
2007; 133:831–832
7. Fang BR, Ng YT, Yeh CH. Intravenous leiomyomatosis with extension to the
heart: echocardiographic features—a case report. Angiology 2007; 58:376–379
Conclusion
Intravenous leiomyomatosis is a rare growth pattern of
uterine leiomyomata in which the histologically benign uter-
AJR:192, March 2009
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AJR Integrative Imaging
LIFELONG LEARNING
FOR RADIOLOGY
AJR Teaching File: Asymptomatic Man with
Giant Negative T Waves on ECG
Anil Attili1, Gisela C. Mueller1, Sharlene M. Day2
Case History
A 40-year-old asymptomatic man presents for a routine
health maintenance examination. The physical examination is normal; in particular, he is normotensive. ECG reveals diffuse deep T wave inversion. His family history is
significant for unexplained sudden cardiac death in his father. MRI was performed to further evaluate an abnormality revealed on echocardiography.
Radiologic Description
Cine bright blood MR images of the heart (Figs. 1A–1F)
obtained with a balanced steady-state free precession technique show thickened myocardium extending from the midventricular to the apical regions of the left ventricle (LV).
The LV septum and lateral wall have a maximum end diastolic thickness of 23 mm (Figs. 1E and 1F). The basal regions of the myocardium, including the basal septum, are
unaffected, and no obstruction of the outflow tract is seen
(Figs. 1C and 1D). The ventricular cavity has a spadelike
configuration, with the extreme apical region being spared.
Review of cine images (Fig. S1) shows the extreme apical
segment to be akinetic. (Supplemental video in three-chamber plane, Fig. S1, is available in supplemental data at www.
ajronline.org.) A delayed contrast-enhanced image shows
enhancement of the thickened myocardium at the apex of
the LV extending to the anterior and inferior walls in a noncoronary-artery distribution sparing the subendocardium
(Figs. 1G and 1H).
Diagnosis
The diagnosis is apical hypertrophic cardiomyopathy.
Commentary
Hypertrophic cardiomyopathy (HCM) is a relatively
common form of genetic heart disease, having an incidence
of 1:500 in the general population, and is the most frequent
cause of sudden cardiac death in the young [1]. Familial
clustering is often observed; the disease is transmitted as a
Mendelian autosomal dominant trait with variable penetrance due to heterogeneous mutations involving any one
of 10 genes encoding for myocardial sarcomere proteins.
The characteristic feature is an inappropriate myocardial
hypertrophy in the absence of an obvious cause such as systemic hypertension or aortic stenosis. Histologically, HCM
is characterized by disorganization and malalignment of
the myofibrils (i.e., myofibrillar disarray) and abnormal intramural coronary arteries characterized by thickened walls
with increased intimal and medial collagen and narrowed
lumen. Such architectural alterations of the microvasculature, as well as the mismatch between myocardial mass and
coronary circulation, are likely responsible for the impaired
coronary vasodilator reserve and bursts of myocardial ischemia that lead to myocyte death and repair in the form of
patchy or transmural replacement scarring.
Different morphologic types of HCM exist [2]. In most
patients, the ventricular septum and the anterior LV wall
are preferentially involved, with abnormalities most prominent in the basal segments (asymmetrical septal hypertrophy). The LV end-diastolic septal thickness is typically
greater than 15 mm. During systole, deformation and bulging of the hypertrophied septum into the left ventricular
outflow tract (LVOT) produce flow acceleration and a pressure drop across the LVOT. Anterior movement and eventual apposition of the anterior mitral valve leaflet to the
septum may occur (systolic anterior motion phenomenon),
further contributing to the dynamic LVOT obstruction.
Secondary mitral regurgitation is often observed. Other less
frequent forms of HCM include the apical form, midventricular hypertrophy, and concentric LV hypertrophy patterns [2].
Apical HCM is a relatively rare form of HCM that was
first described in Japan, where it represents 13–25% of the
entire HCM population. Outside Japan, apical HCM is less
common and has been reported in 3–11% of all HCM patients [3]. The typical features of apical HCM consist of giant T wave negativity on the ECG and hypertrophy confined
Keywords: hypertrophic cardiomyopathy, MRI
DOI:10.2214/AJR.07.7116
Received July 31, 2008; accepted without revision August 12, 2008.
1
Department of Radiology, Division of Cardiothoracic Radiology, East Ann Arbor Health and Geriatrics Center, University of Michigan, 4260 Plymouth Rd., Rm. 1847 SPC 2713, Ann Arbor,
MI 48109-2713. Address correspondence to A. Attili ([email protected]).
Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan Medical Center, Ann Arbor, MI.
2
AJR 2009;192:SXX–SXX 0361–803X/09/1923–SX © American Roentgen Ray Society
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AJR:192, March 2009
Attili et al.
A
B
C
D
Fig. 1—40-year-old man with giant negative T waves on ECG. See also Figure S1 in supplemental data at www.ajronline.org.
A and B, Four-chamber images of heart in diastole (A) and systole (B) using balanced steady-state free precession (SSFP) MRI technique. Note thickening confined
to apical portions of left ventricle, producing spadelike left ventricular cavity.
C and D, Left ventricular outflow tract images in diastole (C) and systole (D) using balanced SSFP MRI technique show thickening of apical regions of left ventricular
myocardium and sparing of basal region. There is no obstruction of left ventricular outflow tract.
(Fig. 1 continues on next page)
S2
AJR:192, March 2009
Negative T Waves on ECG
E
F
G
H
Fig. 1 (continued)—40-year-old man with giant negative T waves on ECG.
E and F, Short-axis images through apex of left ventricle in diastole (E) and systole (F) using balanced SSFP MRI technique show left ventricular septum and lateral
wall have maximum end-diastolic thickness of 23 mm. Cavity of left ventricle is obliterated in systole.
G and H, Delayed myocardial enhancement images in four-chamber plane show enhancement of thickened myocardium at apex. Enhancement involves both anterior
and inferior walls and is not in distribution of a single epicardial coronary artery. Subendocardial region is spared.
to the distal portions of the LV wall, producing a spadelike
configuration of the LV cavity [4, 5]. These patients have
no LVOT obstruction. Apical HCM is not associated with
sudden cardiac death and has a relatively benign prognosis
in terms of cardiovascular mortality [3]. However, one third
of patients with apical HCM may develop unfavorable clinical events and potentially life-threatening morbid complications, such as apical myocardial infarction, arrhythmias,
and stroke. Apical myocardial infarction and aneurysm formation in the presence of normal coronary arteries is a rec-
AJR:192, March 2009
ognized complication of apical HCM [6]. Various degrees of
abnormal apical segments may occur, ranging from a large
apical aneurysm requiring surgical removal to apical hypokinesis [3].
Clinically, HCM requires an accurate diagnosis, determination of the distribution of hypertrophy and its functional
consequences, and assessment of the likelihood of sudden
death and progression to heart failure.
Two-dimensional and Doppler echocardiography are the
most commonly used noninvasive methods for studying
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Attili et al.
HCM. However, the 3D nature of cardiac MRI allows precise definition of the site and extent of hypertrophy and
has been shown to be more accurate than echocardiography
for determining regional hypertrophy and identifying the
different phenotype forms. In particular, the apical form of
HCM may be undetected on echocardiography because of
near-field problems with the echo probe [7, 8]. Cardiac MRI
can identify regions of LV hypertrophy not readily recognized by echocardiography and may be solely responsible
for the diagnosis of the HCM phenotype in an important
minority of patients. Cardiac MRI enhances the assessment
of LV hypertrophy, particularly in the anterolateral LV
free wall and apex, and is a powerful supplemental imaging
test with distinct diagnostic advantages for selected HCM
patients. Particularly in patients in whom echocardiography is technically unsatisfactory, cardiac MRI should be
considered the technique of choice for diagnosing and following up patients with all variants of HCM [9].
Cardiac function and flow dynamics at the LVOT in the
event of LVOT obstruction are also well characterized by
cardiac MRI. The turbulent jet across the LVOT during systole is easily detected by cine MRI, and gradients across the
LVOT can be quantified using velocity-encoded techniques.
The systolic anterior motion of the anterior mitral valve, a
feature of the obstructive form of HCM, is readily detectable
by cardiac MRI, and any consequent mitral regurgitation
can be quantified. Cardiac MRI tagging may be used to identify abnormal patterns of strain, shear, and torsion in HCM,
showing significant dysfunction in hypertrophic areas [10].
More recently, late-enhancement gadolinium cardiac
MRI has been used in HCM to show areas of fibrosis [11–13].
Enhancement was invariably found in hypertrophied regions, with the pattern being patchy and multiple foci predominantly involving the middle third of the ventricular
wall and the junction of the ventricular septum and right
ventricular free wall. The extent of enhancement was positively correlated with wall thickness and inversely correlated with systolic wall thickening in the hypertrophied regions. Preliminary data in a selected group of patients
suggest that a correlation exists between the extent of enhancement detected by cardiac MRI and the clinical risk
factors for sudden death, LV dilatation, and heart failure in
HCM patients [13]. In a more recent study of a large HCM
cohort with no or only mild symptoms, myocardial fibrosis
detected by cardiac MRI was associated with a greater likelihood and increased frequency of ventricular tachyarrhythmias on ambulatory ECG using a Holter monitor [14].
Identifying patients at high and low risk is an important
but problematic aspect of the clinical management of
HCM, particularly with the availability of an effective but
not hazard-free treatment option, the implantable cardioverter-defibrillator.
Treatment strategies depend on appropriate patient selection, including drug treatment for exertional dyspnea
S4
(β-blockers, verapamil, disopyramide) and the septal myotomy–myectomy operation, which is the standard of care
for severe refractory symptoms associated with marked
outflow obstruction; alcohol septal ablation and pacing are
alternatives to surgery for selected patients [1]. Sudden cardiac death is the most dreaded complication and is most
common in adolescents and young adults who are often
asymp­tomatic. The currently recognized major risk factors
for sudden cardiac death in HCM include unexplained syncope (particularly when exertional or recurrent), a family
history of HCM-related sudden death, identification of
high-risk mutant genes, frequent multiple or prolonged episodes of nonsustained ventricular tachycardia on Holter
monitoring, abnormal blood pressure response to exercise,
and extreme degrees of LV hypertrophy (maximum LV
wall thickness ≥ 30 mm) [15]. Risk stratification for sudden
cardiac death is of critical importance, and high-risk patients may be treated effectively for sudden death prevention with placement of an ICD [16].
Objective
The educational objective of this article is to describe the
MRI features of apical HCM and to discuss the usefulness
of MRI in the diagnosis of HCM.
Conclusion
Apical HCM is a relatively rare form of HCM characterized by deep negative T waves on ECG, hypertrophy involving the apical regions of the heart not associated with
LVOT obstruction, and a relatively benign prognosis in
terms of cardiovascular mortality. Cardiac MRI allows precise definition of the site and extent of hypertrophy in
HCM and is more accurate than echocardiography for determining regional hypertrophy and identifying different
phenotypes such as the apical form of HCM, which may be
undetected on echocardiography. Preliminary data have
shown that MRI delayed hyperenhancement in HCM is associated with markers of sudden cardiac death and progressive disease, with possible additional prognostic information for risk stratification.
References
1.Maron BJ. Hypertrophic cardiomyopathy: a systematic review. JAMA 2002;
287:1308–1320
2.Wigle ED. Cardiomyopathy: the diagnosis of hypertrophic cardiomyopathy.
Heart 2001; 86:709–714
3.Eriksson MJ, Sonnenberg B, Woo A, et al. Long-term outcome in patients with
apical hypertrophic cardiomyopathy. J Am Coll Cardiol 2002; 39:638–645
4.Sakamoto T, Tei C, Murayama M, Ichiyasu H, Hada Y. Giant T wave inversion
as a manifestation of asymmetrical apical hypertrophy (AAH) of the left ventricle: echocardiographic and ultrasono-cardiotomographic study. Jpn Heart J
1976; 17:611–629
5.Yamaguchi H, Ishimura T, Nishiyama S, et al. Hypertrophic nonobstructive
cardiomyopathy with giant negative T waves (apical hypertrophy): ventriculographic and echocardiographic features in 30 patients. Am J Cardiol 1979;
44:401–412
6.Matsubara K, Nakamura T, Kuribayashi T, Azuma A, Nakagawa M. Sustained
AJR:192, March 2009
Negative T Waves on ECG
cavity obliteration and apical aneurysm formation in apical hypertrophic
cardiomyopathy. J Am Coll Cardiol 2003; 42:288–295
7.Moon JC, Fisher NG, McKenna WJ, Pennell DJ. Detection of apical hypertrophic cardiomyopathy by cardiovascular magnetic resonance in patients with
non-diagnostic echocardiography. Heart 2004; 90:645–649
8.Rickers C, Wilke NM, Jerosch-Herold M, et al. Utility of cardiac magnetic
resonance imaging in the diagnosis of hypertrophic cardiomyopathy. Circulation 2005; 112:855–861
9.Pennell DJ, Sechtem UP, Higgins CB, et al. Clinical indications for cardiovascular magnetic resonance (CMR): Consensus Panel report. Eur Heart J 2004;
25:1940–1965
10.Dong SJ, MacGregor JH, Crawley AP, et al. Left ventricular wall thickness and
regional systolic function in patients with hypertrophic cardiomyopathy: a
three-dimensional tagged magnetic resonance imaging study. Circulation
1994; 90:1200–1209
11.Bogaert J, Goldstein M, Tannouri F, Golzarian J, Dymarkowski S. Late myocardial enhancement in hypertrophic cardiomyopathy with contrast-enhanced
MR imaging. AJR 2003; 180:981–985
12.Choudhury L, Mahrholdt H, Wagner A, et al. Myocardial scarring in asymptomatic or mildly symptomatic patients with hypertrophic cardiomyopathy. J
Am Coll Cardiol 2002; 40:2156–2164
13.Moon JC, McKenna WJ, McCrohon JA, Elliott PM, Smith GC, Pennell DJ.
Toward clinical risk assessment in hypertrophic cardiomyopathy with gadolinium cardiovascular magnetic resonance. J Am Coll Cardiol 2003;
41:1561–1567
14.Adabag AS, Maron BJ, Appelbaum E, et al. Occurrence and frequency of arrhythmia in hypertrophic cardiomyopathy in relation to delayed enhancement on
cardiovascular magnetic resonance. J Am Coll Cardiol 2008; 51:1369–1374
15.Elliott PM, Poloniecki J, Dickie S, et al. Sudden death in hypertrophic cardiomyopathy: identification of high risk patients. J Am Coll Cardiol 2000;
36:2212–2218
16.Maron BJ, Shen WK, Link MS, et al. Efficacy of implantable cardioverter–
defibrillators for the prevention of sudden death in patients with hypertrophic
cardiomyopathy. N Engl J Med 2000; 342:365–373
F O R YO U R I N F O R M AT I O N
A data supplement for this article can be viewed in the online version of the article at: www.ajronline.org.
AJR:192, March 2009
S5
Erratum
Author Corrections
In the article titled “Radiological Reasoning: Algorithmic Workup of Abnormal Vaginal Bleeding with Endovaginal Sonography and Sonohysterography,”
which appeared in the December 2008 issue of AJR Integrative Imaging (AJR 2008; 191[suppl]:S68–S73), the criteria for normal endometrial thickness
reported in the algorithm in Figure 3 was inaccurate. The corrected algorithm appears here.
We sincerely regret this error.
Ann A. Shi
Montefiore Medical Center
Bronx, NY
Susanna I. Lee
Massachusetts General Hospital
Boston, MA
Postmenopausal bleeding and premenopausal
bleeding unresponsive to hormonal or medical therapy
Endovaginal ultrasound
Normal endometrium
< 5 mm postmenopausal
< 16 mm premenopausal
Abnormal endometrium
abnormal thickness or morphology
Focal lesion workup
Endometrial biopsy
Sonohysterography
Benign
Focal lesion
No focal lesion
Hysteroscopic resection
Endometrial biopsy or
D&C if bleeding persists
Premenopausal bleeding with
high risk for endometrial cancer*
Malignant
Inadequate sample
Cancer surgery
Repeat endometrial
biopsy or D&C
*Age > 35 years old, morbid obesity, chronic diabetes or hypertension, chronic tamoxifen exposure.
Fig. 3—Algorithm for evaluating women with abnormal vaginal bleeding. In asymptomatic postmenopausal women, endometrial thickness of > 6 mm (for patients not
undergoing hormone replacement therapy) or > 8 mm (for those receiving hormone replacement therapy) is considered abnormal and should trigger a similar workup for
endometrial abnormalities [24]. Threshold for workup of asymptomatic women taking tamoxifen is controversial, with endometrial thickness cutoffs of 5–8 mm having been
proposed. D&C = dilatation and curettage.
AJR:192, March 2009
S1