MSCT后处理技术对坏疽性胆囊炎的影像特征分析

目的：采用多平面重组（MPR）及最大密度投影（MIP）技术，探讨坏疽性胆囊炎的 MSCT 影像特征。方法：搜集2013年1月－2015年3月本院经手术病理证实的28例坏疽性胆囊炎（A 组）及20例单纯性胆囊炎（B 组）的影像资料。全部病例均行64层 MSCT 平扫和双期增强扫描并采用 MPR 及 MIP 后处理，对比分析两组病例的 MSCT 影像特征。结果：A 组胆囊最大横径（4．43±0．88）cm 大于 B 组（3．04±0．66）cm，P ＝0．000。A 组胆囊壁水肿，其厚度（0．37±0．10）cm大于 B 组（0．28±0．09）cm（P ＝0．005）；A 组24例（86％）胆囊壁广泛／灶状模糊。A 组胆囊壁呈不完整线样强化，轻度强化23例（82％），中度强化5例（18％）；B 组胆囊壁完整线样强化，轻度强化2例（10％），中度强化15例（75％），重度强化3例（15％），两组强化幅度差异有统计学意义（P ＝0．002）。A 组中13例（76％）清晰显示胆囊动脉并狭窄、闭塞；B 组3例（16％）显示胆囊动脉轻度狭窄。以胆囊最大横径≥4．40 cm、胆囊壁厚≥0．32 cm、胆囊动脉单支及多支狭窄闭塞为指标诊断坏疽性胆囊炎的符合率为79％。A 组中26例（93％）合并胆囊结石，12例（43％）合并胆囊周围脓肿，16例（58％）合并腹膜炎；B 组中18例（90％）合并胆囊结石。结论：胆囊显著增大，壁增厚，结构模糊甚至消失，胆囊壁不完整线样低强化并合并胆囊周围脓肿、腹膜炎，是坏疽性胆囊炎影像特征；胆囊动脉节段性狭窄、闭塞是诊断坏疽性胆囊炎最有力的征象。

Application of CT post-processing technique in imaging analysis of gangrenous cholecystitis

Objective:To study the MSCT features of gangrenous cholecystitis using post-processing technique inclu-ding multi-planar reformation (MPR)and maximal intensity projection (MIP).Methods:Imaging materials of twenty eight patients with surgery and pathology proven gangrenous cholecystitis (Group A)and twenty patients with simple cholecysti-tis (Group B)treated in our hospital in the period of January 2013 to March 2015 were analyzed.All patients underwent plain and dual-phase contrast-enhanced CT scanning,the raw data were reformatted with MPR and MIP.The imaging fea-tures of these two groups were compared and analyzed.Results:The average largest transverse dimension of the gallbladder in Group A was (4.43±0.88)cm,which was larger than that of Group B (3.04±0.66)cm,with statistic difference (P =0.000).The thickness of edematous gallbladder wall in Group A was (0.37±0.10)cm,which was more than that of Group B (0.28±0.09)cm,with statistic difference (P =0.005).Twenty four patients (86%)of Group A had the gallbladder wall partially or completely blurred.The wall of gallbladder in Group A showed intermittent linear enhancement,which were mild in 23 patients (82%),moderate in 5 patients (18%),while the gallbladder wall showed continuous linear enhancement in Group B and enhanced mildly in 2 patietns (10%),moderately in 15 patients (75%),heavily in 3 patients (15%),with statistical differences (P =0.002).The gallbladder arteries showed stenosis or occlusion in 13 patients (76%)in Group A, while only 3 patients (16%)of Group B showed mild arterial stenosis.Taking the maximum transverse dimension of gall-bladder ≥4.40cm,wall thickness ≥0.32cm and single/multiple gallbladder artery stenosis/occlusion as criteria,the diag-nostic accuracy was 79%.Complication of Group A included gallstone in 26 patients (93%),peri-gallbaldder abscess in 12 patients (43%)and peritonitis in 16 patients (58%).Eighteen patients (90%)in Group B accompanied with gallstone. Conclusion:Marked enlargement of gallbladder,and wall thickening with partial or complete structural blurring/disappearing and intermittent linear enhancement accompanied with peri-gallbladder abscess/peritonitis are the characteristics imaging features of gangrenous cholecystitis.Presence of segmental stenosis and occlusion of gallbladder artery provides more help-ful information in the diagnosis.