Increased CT Attenuation of Pericolic Adipose Tissue as a Noninvasive Marker of Disease Severity in Ulcerative Colitis
- Author:
Jun LU
1
;
Hui XU
;
Jing ZHENG
;
Tianxin CHENG
;
Xinjun HAN
;
Yuxin WANG
;
Xuxu MENG
;
Xiaoyang LI
;
Jiahui JIANG
;
Xue DONG
;
Xijie ZHANG
;
Zhenchang WANG
;
Zhenghan YANG
;
Lixue XU
Author Information
- Publication Type:Original Article
- From:Korean Journal of Radiology 2025;26(5):411-421
- CountryRepublic of Korea
- Language:English
-
Abstract:
Objective:Accurate evaluation of inflammation severity in ulcerative colitis (UC) can guide treatment strategy selection. The potential value of the pericolic fat attenuation index (FAI) on CT as an indicator of disease severity remains unknown.This study aimed to assess the diagnostic accuracy of pericolic FAI in predicting UC severity.
Materials and Methods:This retrospective study enrolled 148 patients (mean age 48 years; 87 males). The fat attenuation on CT was measured in four different locations: the mesocolic vascular side (MS) and opposite side of MS (OMS) around the most severe bowel lesion, the retroperitoneal space (RS), and the subcutaneous area. The fat attenuation indices (FAI MS, FAI OMS, and FAI RS) were calculated as the fat attenuation measured in MS, OMS, and RS, respectively, minus that of the subcutaneous area, and were obtained in the non-enhanced, arterial, and delayed phases. Correlations between the FAI and UC Endoscopic Index of Severity (UCEIS) were assessed using Spearman’s correlation. Predictors of severe UC (UCEIS ≥7) were selected by univariable analysis. The performance of FAI in predicting severe UC was evaluated using the area under the receiver operating characteristic curve (AUC).
Results:The FAIMS and FAI OMS scores were significantly higher than FAI RS in three phases (all P < 0.001). The FAIMS and FAI OMS scores moderately correlated with the UCEIS score (r = 0.474–0.649 among the three phases). Additionally, FAI MS and FAI OMS identified severe UC, with AUC varying from 0.77 to 0.85.
Conclusion:Increased CT attenuation of pericolic adipose tissue could serve as a noninvasive marker for evaluating UC severity. FAI MS and FAI OMS of three phases showed similar prediction accuracies for severe UC identification.
