Download Did You Know? - Quantum Radiology

FoCUs
Expertise i n I m a g i n g
Corporate Headquarters
61 Whitcher Street • Suite 3150
Marietta, Georgia 30060
Phone: 678.239.0420
Fax: 678.626.0350
www.quantumradiology.com
NEW IMAGING
CENTERS
NOW OPEN!
Acworth Health Park
Canton Imaging Center
Georgia Vein Specialists – Marietta
598 Nancy Street, Suite 150, Marietta
(678) 626-0019
Georgia Vein Specialists– Douglasville
6002 Professional Parkway, Suite 260, Douglasville
(678) 626-0019
Medica Imaging Centers
Medica Forsyth MRI, CT, US and DEXA
925 Sanders Rd. Suite B, Cumming
(678) 845-2150
Medica at Rabun Open MRI
7499 Old Hwy 441 South, Lakemont
(706) 782-0770
WellStar Outpatient Imaging Centers
Kennestone Imaging Center - 210 Building
(770) 793-7800
Towne Lake Imaging Center
(678) 494-2440
Kennestone Imaging Center- 700 Building
(770) 420-1750
Cobb Imaging Center
(678) 945-8640
Kennestone Imaging Center - 340 Building
(770) 793-7880
Cobb CT Imaging Center – 1700 Building
(678) 398-0780
Kennestone - Imaging Center at 55 Whitcher
Street
(678) 337-7000
Cobb Hospital – Women’s Imaging Center
(770) 732-5100
Kennestone Hospital – Women’s Center and
3.0T Imaging MRI
(770) 793-8030
Acworth Health Park Imaging Center
(770) 917-8150
Canton Imaging Center
(770) 479-4847
East Cobb Imaging Center
(770) 793-9200
Douglas Imaging Center
(678) 715-6601
Douglas Imaging Center – Professional Parkway
(678) 838-2590
WellStar Paulding Imaging Center
(770) 443-7700
WellStar Windy Hill Imaging Services
(770) 644-1240
Evolving Indications for
CT and MRI in Children
CT scans utilize interaction of electrons with ionizing
radiation in order to generate images.
They are fast, have
excellent spatial
resolution and are
preferred by most
clinicians since
they are easier
to understand.
However, children are more sensitive than adults to the
deleterious affects of ionizing radiation, though the risks
are small and difficult to quantify in most situations.
Magnetic Resonance Imaging (MRI), on the other
hand, takes advantage of the interaction of protons with
magnetic fields in order to generate images. MRI has
excellent tissue characterization capability and is free
of ionizing radiation, but the longer duration of MR
exams often necessitates sedation or general anesthesia
depending on the age of the child.
from the President
INTRODUCING…
PEDIATRIC IMAGING!
We all know that pediatrics is not adult
medicine for small people. Children’s
diseases, diagnostic processes, management
issues, and treatments are vastly different
from those for adults. The same is true
for medical imaging. Medical imaging of
children is not just adult imaging with small
equipment.
I would like to introduce the newest member of Quantum Radiology, Dr. Zahir
Momin, who will be heading up our pediatric imaging program. He recently finished
a one-year pediatric radiology fellowship at
Children’s Hospital of Michigan. Prior to
that, he completed a radiology residency and
The indications for CT and MRI are constantly
changing as both modalities are evolving and
leapfrogging one another in many applications.
Continues on page 2
about the Doctor
Zahir Momin, M.D.
Medical College of Georgia, 2005
Residency: Diagnostic Radiology,
Emory University, 2010
Fellowship: Pediatric Imaging, Children’s Hospital of Michigan, 2011
Continues on page 2
I n s I d E
Pediatric
Imaging
Medica Stand-Up MRI of Atlanta
6590 Powers Ferry Road, Atlanta
(770) 953-0108
Expertise in Imaging
o u R l o C aT I o n s
Georgia Vein Specialists
Quantum Radiology is the only group in our market providing 24/7 service.
Our 45 sub-specialized radiologists read over 750,000 exams per year.
Q U A N T U M
Quantum Radiology
Did You Know?
VolUMe 5
IssUe 2
Pediatric Imaging Cont. .......Page 2
Letter from the President ...........Page 2
MRA, Vascular Imaging Tech. .......Page 3
MRA, Vascular Imaging Tech. Cont. Page 4
SPECT/CT Imaging .........................Page 5
SPECT/CT Imaging Continued .......Page 6
GA Vein Specialists .....................Page 7
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Pag e
2
Pag e
EVolVInG InDICaTIons FoR CT anD MRI In CHIlDREn
Continued from page 1...
Traditionally, brain, spine, and musculoskeletal systems have been better
evaluated with MRI, whereas chest, abdomen and pelvis have been better
evaluated with CT. Recent advances in MRI have narrowed, if not
reversed, CT’s lead in cardiac and abdominal/pelvic imaging, with MR
now being the first line modality for evaluation of heart, great vessels, and
solid abdominal organs.
from the President
a fellowship in musculoskeletal imaging
at Emory.
Dr. Momin is now available to answer
your questions regarding pediatric
imaging exams. He can be reached
through our physician-to-physician line,
404-WE-XRAY-1. Dr. Momin is currently assisting in the planning of WellStar’s Pediatric Diagnostic Center, which
will feature dedicated children’s imaging
services in a kid-friendly environment.
Please read the article by Dr. Momin in
this issue of Quantum Focus.
In the near future, I hope he will meet
many of you.
Pediatric MRI of the Liver
Pediatric CT of the Chest
This trend is likely to continue in the foreseeable future, with the number
of CTs progressively declining and the number of MRs progressively
increasing at most major pediatric hospitals across the country. In the
meantime, CT scanners continue to improve technology and promise to
reduce radiation doses by 50-90% without sacrificing image quality. This
technology will become readily available in the next several years and
likely slow down, if not reverse this trend completely.
Alan Zuckerman, M.D.
President
What are the symptoms? Will they get
worse?
In addition to the visual appearance, many
patients may experience one or more of
the following leg symptoms:
ashutosh Rao, M.D.
Emory University School of
Medicine, 1996
Residency: Diagnostic
Radiology, University of Texas
Southwestern, 2001
Columbia University, 1985
Fellowship: Cardiovascular and Interventional Radiology, The John Hopkins
Hospital, 1991
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President
alan Zuckerman, M.D.,
President
Residency: Diagnostic Radiology, Northshore University Hospital-Cornell University
Medical Center, 1990
QR_News_9_2012_FALL_Final.indd 4-5
Varicose Veins
affect an estimated 40 percent
of women and 25
percent of men.
Factors leading
to varicose veins
include heredity,
gender, pregnancy, age and other
factors. Some factors may speed up the
development of this disease and make the
veins worse, including prolonged standing, obesity, hormone levels, and physical
trauma.
our Team
Body Imaging
» Joseph J. armistead, M.D.
» James Bricker Burns, M.D.
» Walter L. Meier, III, M.D.
» Joseph H. Moyers, M.D.
» gregory B. Smith, M.D.
» James M. Tallman, M.D.
If a patient experiences symptoms and
» Mark L. Wetherly, M.D.
delays treatment, the symptoms may
Breast Imaging
progress onward to more serious
» Linda K. Blom, M.D.
Before
complications including:
» Steven D. Brantley, M.D.
» Robert e. Chandlee, M.D.
• Inflammation (phlebitis)
» William C. Chocallo, M.D.
• Blood clots (e.g., DVT)
» Thomas W. Hinz, M.D.
• Ankle sores or skin ulcers
» Kip Lynch, M.D.
• Bleeding.
» anna Meyerson, M.D.
» Martin L. Silbiger, M.D.
If your patients are
» augustus g. Vaughn, Jr., M.D.
experiencing any
» Brant S. Vincent, M.D.
of the above, please
» John e. Williams, M.D.
consult Georgia
» Michael H. Wolff, M.D.
After
Cardiac
Imaging
Vein Specialists at
»
aaron
Cann, M.D., Ph.D.
678.626.0019, as
» Jaydip Datta, M.D.
treatment may be
» K. Scott early, M.D.
required.
» Nikhil Parsh, M.D.
» Stuart Resnick, M.D.
Interventional Radiology
» John e. Bianco, M.D.
» glenn a. Kerwin, M.D.
Glenn Kerwin, M.D.
» Chad Kuhlman, M.D.
Emory University School
» Thomas P. Murphy, M.D.
of Medicine, 1994
» Sepehr Panah, M.D.
Residency: Diagnostic
» ashutosh Rao, M.D.
Radiology, Emory School of
Medicine, 1999
» Mark Silverstein, M.D.
» alan M. Zuckerman, M.D.
Fellowship: Vascular and
Interventional Radiology,
Musculoskeletal Imaging
Emory University School
» John gira, M.D.
of Medicine, 2000
» Jay Patel, M.D.
» Robert Pham, M.D.
» edward Robertson, M.D.
Pediatric Imaging
» Zahir Momin, M.D.
Neuroradiology
»Sarah Bochar, M.D.
»Jay Cinnamon, M.D.
Second Edition
»Brian T. Kaineg, M.D.
accurate and easily accessible guidelines for
»Robert H. Stephenson, Jr., M.D.
»Terry Ward, M.D.
referring clinicians to order imaging studies
»Scott Wottrich, M.D.
Nuclear Medicine and PET
» Brian M. gordon, M.D.
To request a copy of the ordering guide,
Executive Director
contact Quantum Radiology marketing at
» adam Fogle, MBa
[email protected]
• Pain (an aching or cramping feeling)
• Heaviness/Tiredness
• Burning or tingling sensations
• Swelling/Throbbing
• Tender areas around the veins.
G e o r g i a Ve i n S p e c i a l i s t s
a bo u t t he Doctor
Because of the constant evolution and developments in pediatric imaging,
the “textbook” answer for preferred modality for a specific indication is
likely to be outdated. Pediatric care providers should work closely with
radiologists in order to choose the best modality to answer their clinical
question. Quantum radiologists welcome this interaction and strive to
keep their referring clinicians informed of exciting developments in this
rapidly evolving subspecialty.
.
GEoRGIa VEIn sPECIalIsTs
7
Fellowship: Vascular and
Interventional Radiology,
Harvard University School of
Medicine, 2002
Quantum
Ordering Guide
NOW AVAILABLE!
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MRa
sPECT/CT IMaGInG
noVEl VasCulaR IMaGInG TECHnIquEs
In THE WEllsTaR sYsTEM
Continued from page 3...
When it comes to imaging the vascular system, there
is no magic bullet.
are often asymptomatic and surgery prior to
SPECT/ CT imaging often required bilateral
exploration of the neck for definitive treatment.
SPECT/CT imaging is very useful in evaluating patients
with prostate cancer. ProstaScint is a monoclonal
antibody utilized for identifying metastatic
lymph nodes in patients with prostate cancer.
Patients who are deemed appropriate candidates
for ProstaScint imaging should have a negative
bone scan since skeletal metastatic disease would
obviate a ProstaScint scan. If the patient has a
negative bone scan and a rising PSA, a ProstaScint
SPECT/CT scan is particularly useful. The
ProstaScint SPECT/CT scan enables detection
of metastatic disease within normal sized lymph
Parathyroid adenoma in anterior mediastinum. This may have been
nodes in the retroperitoneum, mediastinum and
missed on conventional nuclear medicine imaging.
supraclavicular regions. Prior to SPECT/CT
imaging planar ProstaScint imaging was inaccurate
90% of these patients are due to a single parathyroid
since very small metastatic lymph nodes can be present
adenoma. Utilizing SPECT/CT imaging localization of
resulting in elevated PSA levels. If the patient is found
the parathyroid adenoma has been enhanced particularly
not to have metastatic disease in distant sites, the patient
in ectopic sites such as in the superior mediastinum.
may be a candidate for localized radiation therapy and
the ProstaScint imaging; therefore it has a significant
SPECT/CT scans are available in the WellStar system.
impact on both patient therapy and on prognosis.
To order a SPECT/CT scan, please call WellStar
SPECT/CT imaging can also be used in benign
scheduling. Further information can be obtained by
conditions, such as patients with primary
contacting John Huey at Windy Hill Hospital at
770-644-1247 or Dr. Brian Gordon at 770-793-7872.
Brian M. Gordon, M.D.
hyperparathyroidism. These patients are evaluated with
technetium sestamibi for the presence of a parathyroid
adenoma. Anatomic localization is very important for
preoperative evaluation of these patients. These patients
University of the Witwatersrand Medical
School, Johannesburg, South Africa, 1985
Internal Medicine, Military Hospital,
Pretoria, 1989
Pediatrics, James Paget Hospital, Great
Yarmouth, Great Britain,1990
Radiology, University of Witwatersrand
Teaching Hospitals,
Johannesburg, 1991
Residency: Diagnostic Radiology, Medical
University of South Carolina, Charleston,
South Carolina, 1995
Fellowship: Nuclear Medicine, Medical
University of South Carolina, Charleston,
South Carolina, 1996
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QR_News_9_2012_FALL_Final.indd 6-7
Ultrasound is powerful and inexpensive but fails in larger
patients, in central vessels, and is not quantitative. The most
popular high resolution technique, CT angiography, relies
on ionizing radiation and should only be used sparingly in
sensitive populations such as children and young adults.
Patients with renal disease, with certain allergies, or who
cannot hold still are not candidates. Magnetic resonance
imaging (MRI) has been an often inferior alternative due to
technical challenges and resolution limitations. Fortunately,
improvements in MRI now provide a range of high quality
options for imaging the blood vessels of almost any patient.
Our newest tool, blood pool MR angiography, can be used
to obtain high resolution vascular maps without the risk of
radiation exposure or contrast induced acute kidney injury.
Blood pool MR angiography is particularly useful in the
uncooperative patient and for imaging the venous system.
MR angiography, or MRA, may be performed with or
without the use of IV contrast. Non-contrast techniques
take advantage of the motion of flowing blood through the
plane of imaging. This motion can be used to preserve signal
in the flowing blood while saturating adjacent immobile
tissues, making the flowing blood appear bright against a
dark background. This is the method of choice for patients
with severe renal dysfunction who cannot safely receive
gadolinium due to the risk of nephrogenic systemic fibrosis
(NSF).
Cancer Imaging
a bo u t t h e D oc to r
Left total knee replacement showing loosening of
arthroplasty.
5
Unfortunately, many vessels cannot be reliably imaged
this way. For successful non-contrast MRA, the vessel of
interest must travel in a relatively straight line perpendicular
Figure 1 - Extension of left iliac vein clot into the IVC is
demonstrated, impacting both the route and site of IVC filter
placement.
to the plane of imaging. Tortuous arteries, common in
hypertension, curve in and out of the imaging plane. Many
veins pose a similar challenge. Non-contrast MRA is slow
and requires a cooperative patient with a steady heart rate.
Most importantly, blood flow must be preserved and be of
sufficient velocity. Slowly flowing blood gets saturated just
like the background, resulting in signal loss. A patent vessel
with low velocity flow can appear partially thrombosed or
even occluded. This is an issue in high grade arterial stenosis
and in tandem arterial stenosis but is most problematic in
the veins.
Contrast enhanced MRA using standard gadolinium based
agents mitigates many of these problems. Gadolinium results
in a change in the magnetic properties of tissue, providing
dramatically increased MR signal. Patients are imaged while
the gadolinium is in the blood vessels but has not yet spread
into the surrounding soft tissues and extravascular spaces.
If timing is precise, this results in bright vessels against
a dark background. Contrast enhanced MRA is a much
faster technique and unlike non-contrast techniques, image
quality is independent of the speed and direction of blood
flow. Timing of image acquisition can be varied to maximize
enhancement in either the arteries or veins.
However, it is this close coordination of injection
timing with image acquisition that is the Achilles heel
of traditional contrast enhanced MRA using standard
extracellular gadolinium agents. These compounds stay in
the bloodstream for only a few minutes and rapidly enter
the extravascular space. As the gadolinium concentration
equilibrates across several tissue compartments, signal
differences between the vessel lumen and surrounding tissues
diminish. Optimizing timing for an arterial phase study
can be difficult, particularly in patients with variable cardiac
output. Venous phase imaging is even more of a challenge
due to the dilution of the gadolinium bolus in a greater
volume of distribution. Even in the best case scenario, the
short intravascular time of extracellular gadolinium agents
does not allow high resolution MR imaging. If the initial
contrast bolus is missed, perhaps due to patient motion or
a problem with the injection, the exam is ruined. There is
no second chance and the patient must be rescheduled after
enough delay to permit renal excretion of the gadolinium.
Continues on page 6
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sPECT/CT IMaGInG
MRa
In THE WEllsTaR sYsTEM
Continued from page 5...
Compounds with longer residence time in the vasculature
were developed to address these timing and dilution
problems. Termed “blood pool” gadolinium agents,
drugs such as gadofosveset (Ablavar) bind reversibly to
serum albumin. This keeps the gadolinium in the blood
vessel much longer, allowing high quality images to be
obtained up to an hour after contrast injection. As an
added bonus, albumin binding stabilizes the gadolinium
carrier and dramatically amplifies its effects on MR
signal. Each molecule of bound gadolinium generates
such an improvement in the signal to noise ratio that the
gadolinium dose can be reduced up to 70%.
SPECT/CT imaging is available within the
WellStar system at Windy Hill Hospital. SPECT/
CT imaging combines physiology and anatomy
and improves the anatomic localization of nuclear
medicine scans.
Figure 3: Focal clot in the right internal iliac vein in a patient with symptomatic thrombophlebitis. Successful treatment was confirmed by follow up MRI.
At Quantum
Radiology, we have
incorporated this
new contrast agent
into our imaging
repertoire with
impressive results.
For example, an
uncooperative
patient who failed
CT angiography
Figure 2 – In a patient with
was successfully
suspected renal abscess, nondiagnosed with an
occlusive thrombus was identified
in the left kidney lower pole veins. extensive Standford
Patient was placed on antibiotics
Type A dissection
and anticoagulation with resousing blood pool
lution of clot demonstrated on
MRA. This technically
follow up MRI.
challenging exam had
to be repeated several times and took over 45 minutes.
No other approach would have permitted such prolonged
arterial imaging.
At Quantum Radiology, we strive to select the most
appropriate imaging technique for the benefit of our
patients and referring clinicians. We work closely
with other specialists such as cardiologists and vascular
surgeons to provide comprehensive, integrated patient
care. CT angiography remains our preferred modality for
imaging the vascular system. When possible, we use MR
angiography to spare young patients the risk of radiation
exposure. In patients at risk for acute kidney injury from
iodinated CT contrast (stable GFR 30-40) and in patients
with iodine contrast allergy, we opt for contrast enhanced
MRA. Finally, for venous imaging, blood pool MRA is
our preferred approach.
Our greatest success with blood pool MRA has been
in venous imaging. As shown in the accompanying
figures, we imaged venous thrombus in tissues that were
challenging to interrogate via other modalities. In the
renal abscess case, blood pool MRA demonstrated a
non-occlusive renal vein thrombus that was subsequently
treated with short term anticoagulation. This may have
saved the patient’s kidney.
a bo u t t h e D oc to r
If you are interested in learning more about these
examinations, or if you would like to discuss a particular
patient, please contact the Quantum Radiology Physician
to Physician Line at 404-WE-XRAY-1. One of our
fellowship trained specialists in the Advanced Body
Imaging section will be happy to assist you.
Washington University School of
Medicine, 2002
Residency: Diagnostic Radiology,
Columbia University Medical Center,
2007
Fellowship: MRI, University of
California-San Diego, 2008
Cardiac and
Body Imaging
stuart Resnick, M.D.
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3
SPECT/CT imaging allows anatomic localization
of certain findings on nuclear medicine studies. It
has enhanced certain imaging studies including the
following:
1. Musculoskeletal imaging, bone scintigraphy.
2. Imaging of parathyroid adenomas.
3. Evaluation of neuroendocrine tumors.
4. ProstaScint imaging in patients with prostate cancer.
Spine imaging showing degenerative changes in lumbar
spine and no metastatic disease.
SPECT/CT is also utilized for bone trauma.
SPECT/CT in musculoskeletal imaging can also
help differentiate compression fractures which may be
posttraumatic or spontaneous from compression fractures
which are related to metastatic disease.
SPECT/CT imaging is useful in evaluating patients who
have had joint arthroplasties. The anatomic localization
made possible by the SPECT/CT images may help to
characterize whether the patient has loosening of an
arthroplasty or infection of an arthroplasty device.
Indium Octreotide scan showing metastatic liver lesion
(top left) and metastatic lesion to right iliac bone (top
left) in patient with carcinoid.
SPECT/CT imaging improves the specificity of the
findings on bone scans. This is particularly important in
patients who are being evaluated for metastatic disease.
SPECT/CT bone scintigraphy enables us to differentiate
between degenerative findings within the spine and
metastatic disease within the spine. In addition, lesions
on bone scan detected within the skull can be more
accurately anatomically identified, thus enabling their
characterization.
In musculoskeletal imaging, SPECT/CT has been
utilized for the evaluation of spondylolysis, as well as, for
evaluation and localization of infection or inflammation.
SPECT/CT imaging improves the localization of the
octreotide radiotracer in patients with neuroendocrine
tumors. This is particularly important in evaluating
primary tumors which can be small (less than 1.0 cm
in size) within the pancreas. SPECT/CT imaging also
enables anatomic localization of metastatic disease.
Metastatic disease in the liver as well as within the
skeletal structures can be localized well utilizing
SPECT/CT images in patients with these
neuroendocrine tumors. This is particularly important
for prognostic and therapeutic evaluation. The
neuroendocrine tumors which can be evaluated with
indium octreotide on SPECT/CT imaging include
patients with the following tumors:
•
•
•
•
•
Carcinoid tumor
Pancreatic islet cell tumor
Pheochromocytoma
Medullary carcinoma of the thyroid
Small cell lung cancer
Continues on page 4
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