外伤后肾梗塞皮质缘征的CT表现

目的 评价外伤后肾侧支循环代偿肾皮质缘征的CT表现、发生时间及短期的变化，探索CT检查明确诊断的最佳时间。方法 回顾性研究20例经增强CT扫描确诊的外伤后局灶性或全肾梗塞病例，评价梗塞的大小及肾皮质缘征出现的时间与行CT检查的时问的关系。结果 表现肾皮质缘征14例，其中8例多次行CT检查，最早出现时间是外伤后8h，平均出现时间7d；未表现肾皮质缘征的6例，CT检查均在外伤后10h内进行，平均时间4h。结论 肾脏外伤后侧支循环至少需要8h才能开放，并在CT扫描中显示出来，外伤后1W行CT检查肾皮质缘征显示的阳性率高。

Assessment of the cortical rim sign by CT imaging in posttraumatic renal infarction

Objective To evaluate the incidence and temporal development of the cortical rim sign in posttraumatic renal vascular compromise, and investigate the best time of CT examination. Methods This retrospective study included 20 patients who were diagnosed by contrast-enhanced CT to have posttraumatic focal or global infarcts. The CT scans were reviewed to evaluate the size of infarcts and appearance of the rim sign. Medical records were reviewed to identify the time of trauma in relation to the CT examination. Results 14 cases demonstrated a rim sign, 8 of which had more than one CT,the earliest appearance of the rim sign was at 8 hours after trauma,and median time to appear was 7 days. 6 cases with no rim sign were evaluated within 10 hours of trauma,with a median time of 4 hours. Conclusion It takes a minimum period of 8 hours after trauma for renal collateral circulation to expand and become apparent on CT.CT demonstrated a rim sign in all cases undergoing CT after 1 week.