Download Rectal Ultrasound

Jay Patti
Gillian Lieberman, MD
September 2001
Rectal Ultrasound
Jay Patti
Gillian Lieberman, MD
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Jay Patti
Gillian Lieberman, MD
Patient’s History
• CW is a 66 year old Caucasian female
who presented with a four month history
of painless rectal bleeding.
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Jay Patti
Gillian Lieberman, MD
Our Patient: Pelvic CT
Oral and IV
contrast
Multiple axial images of the
pelvis with contrast
Multiple axial images of the
pelvis with contrast
Rectal Mass
All images are from BIDMC PACS
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Jay Patti
Gillian Lieberman, MD
Our Patient: Rectal Cancer
Oral and IV
contrast
Multiple axial images of the
pelvis with contrast
CT does not yield information about tissue type,
depth of invasion, or cell cytology
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Jay Patti
Gillian Lieberman, MD
Our Patient: Rectal Cancer on Pelvic CT
Multiple axial images of the
pelvis with contrast
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Jay Patti
Gillian Lieberman, MD
CT
• While CT is a good means of identifying masses in
the pelvis its greater utility is in identifying distant
organ involvement. CT yields little information on
the depth of invasion locally of rectal cancer unless
metastases are seen. (Stage IV)1,7
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Jay Patti
Gillian Lieberman, MD
Colonoscopy
• Her colonoscopy showed a pale nodular non-bleeding mass
protruding into the lumen of her upper rectum.
• Colonoscopy offers the ability to directly visualize the
tumor but lacks the ability to define depth of invasion.
Colonoscopy is also used to evaluate the rest of the colon
for other possible lesions. Under direct visualization with
colonoscopy one can biopsy lesions and send tissue samples
for cytology.
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Jay Patti
Gillian Lieberman, MD
Our Patient
Our patient was diagnosed with rectal cancer by
CT and colonoscopic biopsy. She was referred for
endorectal ultrasound for further staging
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Jay Patti
Gillian Lieberman, MD
Endorectal Ultrasound
• Reported to be 72%-97% accurate in determining depth of
tumor invasion with 12% overstaged and 9% understaged.
Sensitivity is 86% and specificity is 33%.2
• Sensitivity and specificity of determining perirectal lymph
node involvement is between 60-90% for both.
• 6-8 weeks after radiation therapy endorectal US measures
resulting fibrosis and is hence less useful although many
have reported that if residual tumor remains it will be
confined to the area of fibrosis.6
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Jay Patti
Gillian Lieberman, MD
Preparation
• Patients need only a phosphate enema prior to examination.
• No sedation, bowel preparation, or patient monitoring is
necessary.
• Patient placed in the left lateral decubitus position with
knees and hips flexed.
• Ultrasound transducer is surrounded by an expandable
balloon that must be filled with water after it is placed in the
rectum.
• Special care must be take to assure that there is no air in the
balloon (shadowing artifact).
• A condom containing transducer jelly is placed over the
transducer before insertion in the rectum.
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Jay Patti
Gillian Lieberman, MD
Normal Rectum
• Most clinicians subscribe to a 5 layer model when
analyzing the appearance of the rectal wall. The
normal rectum appears as hyper- and hypo-echoic
bands around a hypoechoic lumen. There is some
controversy as to the anatomic correlation of the
bands (anatomic layers vs. anatomic interfaces).
There is agreement that the outer hypoechoic band
represents the muscularis propria. (The muscularis
propria is important for staging)
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Jay Patti
Gillian Lieberman, MD
Normal Rectum
Perirectal Fat
Muscularis propria
Submucosa
Muscularis Mucosa
Balloon/Mucosa Interface
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Jay Patti
Gillian Lieberman, MD
Pitfalls
• Anal Verge - If the tumor is at the anal verge it may be
hard to pass the transducer
• Transducer angle - Oblique angle of the wall may cause
blurring and overestimation
• Balloon Inflation - Over inflation causes stacking of layers
and hence overestimation
• Air - In the balloon, ulcer or necrotic tumor will cause
distant shadowing.
• Stool - Artifact of mixed echotexture can appear similar to
villous tumors.
• Surface Contact - Villous adenomas have air in the villi
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Jay Patti
Gillian Lieberman, MD
Rectal Cancer
• 15% of all cancers in men and women occur in the
lower GI tract; 33% of which occur in the rectum1
• Survival is inversely proportional to stage
• Transrectal US is most influential in the treatment
of lower stage tumors.
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Jay Patti
Gillian Lieberman, MD
Staging
• T1 – Submucosal involvement only; Treatment: Full thickness
local excision. Low likelyhood of lymphatic spread (6-11%).
• T2 – Into but not beyond the muscularis propria. There may be
thickening of the muscularis propria with preservation of the
hyperechoic perirectal fat layer; Treatment: Local excision (higher
rate of recurrence) Lymph node involvement in 10-35%.
• T3 – Tumor extends beyond the muscularis propria into the
perirectal fat area; Treatment: Low anterior or abdominoperineal
resection with adjuvant preoperative chemotherapy and/or
radiation.
• T4 – Invasion of adjacent organs or the pelvic wall; Treatment:
depends on the extent of and organs involved.
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Jay Patti
Gillian Lieberman, MD
Our Patient
Perirectal Fat
Muscularis propria
Submucosa
Muscularis Mucosa
Balloon/Mucosa Interface
Loss of clear perirectal fat layer
could be artifactual
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Jay Patti
Gillian Lieberman, MD
Our Patient
Submucosa layer appears intact
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Jay Patti
Gillian Lieberman, MD
Our Patient
Perirectal fat layer appears
disrupted
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Jay Patti
Gillian Lieberman, MD
Our Patient
Perirectal fat layer appears
disrupted
Patient was staged as T2, but T3 disease could not be ruled out
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Jay Patti
Gillian Lieberman, MD
Our Patient
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Jay Patti
Gillian Lieberman, MD
Our Patient
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Jay Patti
Gillian Lieberman, MD
MR
• Sensitivity is 89% and specificity is 68%.
US:Sensitivity is 86% and specificity is 33%.4
• Although MR is slightly better at staging rectal
cancer, it is much more expensive.3,4,5
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Jay Patti
Gillian Lieberman, MD
Summary
We discussed:
•
Normal Rectum & Rectal Cancer
Five Layers: Perirectal Fat, Muscularis propria, Submucosa, Muscularis Mucosa,
Balloon/Mucosa Interface
•
•
•
•
Four Stages: I, II, III, IV
CT
Colonoscopy
Rectal US
Preparation
Technique
Findings
MR
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Jay Patti
Gillian Lieberman, MD
References
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5.
6.
7.
8.
Kruskal JB, Kane RA, Sentovich SM, Longmaid HE. Pitfalls and Sources of Error in Staging Rectal Cancer with
Endorectal US. 1997 Radiographics 17(3)609-626
Gavioli M, Bagni A, Piccagli I, Fundaro S, Natalini G. Usefulness of endorectal ultrasound after preoperative
radiotherapy in rectal cancer: comparison between sonographic and histopathologic changes.Dis Colon Rectum. 2000
Aug;43(8):1075-83.
Blomqvist L, Machado M, Rubio C, Gabrielsson N, Granqvist S, Goldman S, Holm T. Rectal tumour staging: MR
imaging using pelvic phased-array and endorectal coils vs endoscopic ultrasonography.Eur Radiol. 2000;10(4):653-60.
Gualdi GF, Casciani E, Guadalaxara A, d'Orta C, Polettini E, Pappalardo G. Local staging of rectal cancer with
transrectal ultrasound and endorectal magnetic resonance imaging: comparison with histologic findings.Dis Colon
Rectum. 2000 Mar;43(3):338-45.
Hunerbein M, Pegios W, Rau B, Vogl TJ, Felix R, Schlag PM. Prospective comparison of endorectal ultrasound, threedimensional endorectal ultrasound, and endorectal MRI in the preoperative evaluation of rectal tumors. Preliminary
results. Surg Endosc. 2000 Nov;14(11):1005-9.
Rau B, Hunerbein M, Barth C, Wust P, Haensch W, Riess H, Felix R, Schlag PM. Accuracy of endorectal ultrasound
after preoperative radiochemotherapy in locally advanced rectal cancer.Surg Endosc. 1999 Oct;13(10):980-4.
Kim NK, Kim MJ, Yun SH, Sohn SK, Min JS. Comparative study of transrectal ultrasonography, pelvic computerized
tomography, and magnetic resonance imaging in preoperative staging of rectal cancer.Dis Colon Rectum. 1999
Jun;42(6):770-5.
Saclarides TJ. Endorectal ultrasound. Surg Clin North Am. 1998 Apr;78(2):237-49.
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Jay Patti
Gillian Lieberman, MD
Acknowledgments
• Larry Barbaras and Cara Lyn D’amour, our
web masters
• Gillian Lieberman, MD
• Pamela Lepkowski
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