CT Evaluation of Target-like Bowel Wall Thickening

Bae, In Young; Kim, Mi Young; Suh, Chang Hea; Cho, Soon Gu; Kim, Jin Hee; Chung, Won Kyun

Abstract

PURPOSE
The purpose of this study was to evaluate the CT features of target-like bowel wall thickenings and to correlate target layers with histopathologic layers.
MATERIALS AND METHODS
We retrospectively analyzed 37 target-like bowel wall thickenings with inner high-, middle low- and outer high attenuated layers on CT scan. Bowel lesions included 15 cases of ischemic lesion, 12 of inflammation, four of carcinomatosis, four of trauma, and two of radiation enteritis. Target-like bowel wall thickenings were classified into three types : with inner most thickened high-attenuated layer(type I); with middle most thickened low-attenuted layer(type II), and with outer most thickened high-attenuated layer(type III). We analyzed the characteristic CT features of these bowel lesions and correlated target and histopathologic layers in resected bowel specimens.
RESULTS
Target-like bowel wall thickening was type I in 18 cases(49%), type II in 13 cases(35%), and type III in 6 cases(16%). Type I ischemic bowel lesions and inflammations were most common, and were found in 60% and 67% of cases, retrospectively. All cases of trauma were type II and radiation colitis was type III. Histopathologic findings showed that each layer of target lesions did not exactly correlate with histopathologic layers. However, the inner high attenuated layer correlated with mucosa and some submucosa, the middle low-attenuated layer correlated with most submucosa and some muscularis, and the outer high-attenuated layer correlated with muscularis, serosa, and periserosal mesentery.
CONCLUSION
CT features of target-like bowel wall thickenings showed type characteristics according to bowel lesions. Histopathologic comparison and analysis were considered helpful for the differential diagnosis of bowel lesions.