目的：探讨CT仿真结肠镜及肠系膜血管CTA成像在乙状结肠扭转的诊断价值。方法：回顾性分析12例经MSCT检查并且手术外科证实的乙状结肠扭转患者的影像资料，运用CT仿真内窥镜（CTVE）、容积再现（VR）、最大密度投影（MIP）及多平面重组（MRP）等后处理重建技术显示肠管及肠系膜血管。结果： 12例CTVE显示乙状结肠不同程度的积气扩张，11例呈倒“U”形，1例呈“C”形。CTVE显示扭转闭袢的马蹄形肠曲敏感度91.7%（11/12）要高于腹部平片41.6%（5/12），两者统计学上有差异（P<0.05）。8例CTA显示乙状结肠动脉走行位置异常，6例近段扭转，2例结构紊乱；MIP显示2例结肠动脉弓显影稀疏变淡，手术证实肠壁缺血。结论：MSCT结合CT仿真结肠镜及肠系膜血管CTA成像可以直观地显示乙状结肠扭转闭袢的肠曲形态，对判断是否合并肠缺血坏死有一定的诊断价值。

Objective: To analyze diagnostic values of CT virtual colonoscopy and computed tomography angiography imaging of mesenteric vessels for volvulus of sigmoid. Methods: Imaging data of 12 patients were analyzed retrospectively, who were confirmed as volvulus of sigmoid by multislice computed tomography(MSCT) examinations and surgeries. Intestinal canals and mesenteric vessels were shown with CT virtual endoscopy(CTVE), volume rendering(VR), maximum intensity projection(MIP), multi-planar reformation(MPR) and other post-processing reconstruction techniques. Results: CTVE indicated that there were various degrees of pneumatosis and expansion of sigmoid colon in 12 patients, including 11 patients with the shape of "U" and 1 patient with the shape of "C". The horseshoe-shape convolutions sensitivity of closed loop volvulus was 91.7%(11/12) in CTVE, which was higher compared with that in the plain abdominal radiograph(41.6%, 5/12); and there were statistical differences(P<0.05). CTA displayed that there were abnormal courses of sigmoid arteries in 8 patients, proximal segment of volvulus in 6 patients, and disordered structure in 2 patients. MIP showed 2 patients with the development of arterial arch of colon being sparse and pale, which was confirmed as ischemia of the intestinal wall by surgeries. Conclusions: As displayed a certain diagnostic value to judge whether patients combine with intestinal ischemic necrosis or not, MSCT combined with CT virtual colonoscopy and CTA imaging mesenteric vessels can visually show volvulus of sigmoid in closed loop convolutions shape.