Colorectal Polyps on Portal Phase Contrast-Enhanced CT Colonography: Lesion Attenuation and Distinction from Tagged Feces
Seung Soo Lee1,
Seong Ho Park1,
Eugene K. Choi2,
So Yeon Kim1,
Min-Ju Kim1,
Kyoung Ho Lee3 and
Young Hoon Kim3
1 Department of Radiology and Research Institute of Radiology, University of
Ulsan College of Medicine, Asan Medical Center, 388-1 Poongnap2-Dong,
Songpa-Gu, Seoul 138-040, Korea.
2 Weill Medical College of Cornell University, New York, NY.
3 Department of Radiology, Seoul National University College of Medicine, Seoul
National University Bundang Hospital, Seongnam-si, Korea.
View larger version (133K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1A —18-mm sessile villotubular adenoma of rectum in 59-year-old
woman. Transverse images of 72-second delay IV contrast-enhanced CT
colonography in supine position at wide window setting (width, 1,500 H; level,
–400 H) (A) and at soft-tissue window setting (width, 400 H;
level, 20 H) (B) show sessile lesion (arrow) in rectum. Lesion
had lowest attenuation value of 50 H among 48 polyps. At blinded review, all
four reviewers correctly interpreted polyp.
|
|
View larger version (159K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 1B —18-mm sessile villotubular adenoma of rectum in 59-year-old
woman. Transverse images of 72-second delay IV contrast-enhanced CT
colonography in supine position at wide window setting (width, 1,500 H; level,
–400 H) (A) and at soft-tissue window setting (width, 400 H;
level, 20 H) (B) show sessile lesion (arrow) in rectum. Lesion
had lowest attenuation value of 50 H among 48 polyps. At blinded review, all
four reviewers correctly interpreted polyp.
|
|
View larger version (138K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2A —15-mm pedunculated tubular adenoma with high-grade dysplasia
of rectum in 38-year-old man. Transverse images of 72-second delay IV
contrast-enhanced CT colonography in supine position at wide window setting
(width, 1,500 H; level, –400 H) (A) and at soft-tissue window
setting (width, 400 H; level, 20 H) (B) show pedunculated lesion
(arrow) in rectum. Lesion had highest attenuation value of 173 H
among 48 polyps. At blinded review, all four reviewers correctly interpreted
polyp.
|
|
View larger version (159K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 2B —15-mm pedunculated tubular adenoma with high-grade dysplasia
of rectum in 38-year-old man. Transverse images of 72-second delay IV
contrast-enhanced CT colonography in supine position at wide window setting
(width, 1,500 H; level, –400 H) (A) and at soft-tissue window
setting (width, 400 H; level, 20 H) (B) show pedunculated lesion
(arrow) in rectum. Lesion had highest attenuation value of 173 H
among 48 polyps. At blinded review, all four reviewers correctly interpreted
polyp.
|
|
View larger version (121K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3A —15-mm sessile tagged feces in descending colon in 59-year-old
woman without colorectal polyp or mass. Transverse images of 72-second delay
IV contrast-enhanced CT colonography with dietary fecal tagging in supine
position at wide window setting (width, 1,500; level, –400 H) (A)
and at soft-tissue window setting (width, 400 H; level, 20 H) (B) show
sessile homogeneously high-attenuating lesion (arrow) in descending
colon that was interpreted as tagged feces. Attenuation value of tagged feces
was 495 H, which was lowest attenuation value among 41 tagged feces. At
blinded review, all four reviewers correctly interpreted tagged feces.
|
|
View larger version (117K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 3B —15-mm sessile tagged feces in descending colon in 59-year-old
woman without colorectal polyp or mass. Transverse images of 72-second delay
IV contrast-enhanced CT colonography with dietary fecal tagging in supine
position at wide window setting (width, 1,500; level, –400 H) (A)
and at soft-tissue window setting (width, 400 H; level, 20 H) (B) show
sessile homogeneously high-attenuating lesion (arrow) in descending
colon that was interpreted as tagged feces. Attenuation value of tagged feces
was 495 H, which was lowest attenuation value among 41 tagged feces. At
blinded review, all four reviewers correctly interpreted tagged feces.
|
|
View larger version (143K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4A —8-mm tubular adenoma of transverse colon in 67-year-old man.
Transverse images of 72-second delay IV contrast-enhanced CT colonography in
supine position at wide window setting (width, 1,500 H; level, –400 H)
(A) and at soft-tissue window setting (width, 400 H; level, 20 H)
(B) show sessile lesion (arrow) with attenuation value of 114
H in transverse colon. At blinded review, this polyp was misinterpreted as
tagged feces by experienced reviewer who misinterpreted lesion attenuation at
soft-tissue window (B) as artificially high (i.e., tagging agent).
|
|
View larger version (173K):
[in this window]
[in a new window]
[as a PowerPoint slide]
|
Fig. 4B —8-mm tubular adenoma of transverse colon in 67-year-old man.
Transverse images of 72-second delay IV contrast-enhanced CT colonography in
supine position at wide window setting (width, 1,500 H; level, –400 H)
(A) and at soft-tissue window setting (width, 400 H; level, 20 H)
(B) show sessile lesion (arrow) with attenuation value of 114
H in transverse colon. At blinded review, this polyp was misinterpreted as
tagged feces by experienced reviewer who misinterpreted lesion attenuation at
soft-tissue window (B) as artificially high (i.e., tagging agent).
|
|
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
Copyright © 2007 by the American Roentgen Ray Society.
