Purpose. To assess the value of pericolonic findings at CT in the evaluatio
n of the sigmoid colon.
Materials and Methods. A total of 210 CT examinations were retrospectively
reviewed by 3 blinded radiologists. Data was analyzed to determine the inte
robserver correlation and the value of pericolonic and colonic wall finding
s in diagnosis of sigmoid colon pathology.
Results. The interobserver correlation for pericolonic findings was: equal
to or superior to that for colonic wall findings. The presence of abnormal
pericolonic fat was the most sensitive (88 %) and specific (93 %) sign to d
ifferentiate a diseased sigmoid colon from a normal one or from sigmoid div
erticulosis. Wall-thickening was less sensitive (82 %) and specific (76 %).
Findings suggesting malignancy over diverticulitis included acute zone of
transition, focal fatty infiltration, and lymph nodes. Symmetrical and circ
umferential wall thickening, target-like enhancement, and local fatty proli
feration were findings suggesting colitis over diverticulitis. Wall thicken
ing more than 15 mm, involvement of 15 cm or less, asymmetrical involvement
, acute zone of transition, and homogeneous or heterogeneous enhancement we
re findings suggesting malignancy over colitis.
Conclusion. To render a diagnosis, the evaluation of the fat infiltration m
ust prevail on the parietal thickening appreciation.