Usefulness of spectral computed tomography for evaluation of intestinal activity and severity in ileocolonic Crohn's disease.
BACKGROUND
Assessment of intestinal activity and severity of Crohn's disease (CD) is crucial to guide treatment. In this study, we aimed to investigate the accuracy of spectral computed tomography (CT) in this assessment and make a comparison with conventional CT.


METHODS
A total of 50 patients with ileocolonic CD underwent spectral CT scanning. Conventional CT and spectral CT images were reconstructed. Endoscopic lesions were classified as absent, mild lesions and severe lesions. Qualitative and quantitative findings in CT images were compared in these segments. Logistic regressions were established, based on conventional and spectral CT parameters, to predict intestinal activity and severity. Comparisons were made by receiver operating characteristic (ROC) curve.


RESULTS
The results showed that bowel wall hyperenhancement, ulcers on CT images, comb sign, bowel wall thickness, normalized iodine concentration (NIC) and slope of HU curve (λHU) increased significantly (p< 0.01) with endoscopic severity. In predicting intestinal activity, spectral CT demonstrated higher accuracy (99.6%versus94.7%), sensitivity (99.1%versus93.4%) and specificity (99.9%versus94.4%) than conventional CT. In predicting intestinal severity, spectral CT also had higher accuracy (96.5%versus91.9%), sensitivity (96.5%versus92.1%) and specificity (95.8%versus89.8%) than conventional CT. Besides, both NIC and λHUcorrelated significantly with Simple Endoscopic Score for CD (r= 0.833 andr= 0.771; bothp< 0.001), but their correlations with C-reactive protein (r= 0.578 andr= 0.513; bothp< 0.01) and Harvey-Bradshaw Index (r= 0.545 andr= 0.522; bothp< 0.01) were moderate.


CONCLUSIONS
Compared with conventional CT, spectral CT had higher accuracy in detecting intestinal activity and severity of CD, which could be an alternative choice in evaluation of CD.
Division of Gastroenterology and Hepatology; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health; Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; 145 Middle Shandong Road, Shanghai 200001, China.
Jiang Chen
JC
Peng
Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Qi
Q
Feng
Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Jiong
J
Zhu
Division of Gastroenterology and Hepatology; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health; Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; 145 Middle Shandong Road, Shanghai 200001, China.
Jun
J
Shen
Division of Gastroenterology and Hepatology; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health; Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; 145 Middle Shandong Road, Shanghai 200001, China.
Yu Qi
YQ
Qiao
Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Jian Rong
JR
Xu
Division of Gastroenterology and Hepatology; Key Laboratory of Gastroenterology and Hepatology, Ministry of Health; Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University; Shanghai Institute of Digestive Disease; 145 Middle Shandong Road, Shanghai 200001, China.
Zhi Hua
ZH
Ran
ileocolonic Crohn’s disease; normalized iodine concentration; spectral CT; λHU