1 Department of Diagnostic Imaging, The Ottawa Hospital, Ottawa, ON, Canada.
2 Department of Medicine, University of Ottawa, Ottawa, ON, Canada.
AJR Am J Roentgenol. 2018 Jun;210(6):1259-1265. doi: 10.2214/AJR.17.18642. Epub 2018 Apr 9.
The objective of our study was to evaluate the diagnostic performance of CT in the identification of anastomotic leaks.
This was a study of patients who underwent bowel surgery and a subsequent postoperative CT examination performed specifically for investigating for an anastomotic leak. The study group included patients with surgically confirmed anastomotic leaks (n = 59), and the control group included patients without anastomotic leaks (n = 48) confirmed by either repeat surgery or uneventful clinical follow-up for at least 6 months. Two radiologists and two radiology residents independently reviewed each CT examination for specific CT findings from a set of predetermined imaging predictors. The sensitivity and specificity for each imaging predictor were calculated for each reader, and the interobserver agreement was calculated using the Cohen kappa coefficient. Diagnostic performance was assessed using ROC curve analysis.
The most sensitive imaging predictor was intraabdominal free fluid (95.3%). Leakage of intraluminal contrast agent was also a highly specific imaging predictor (96.6%). Substantial interobserver agreement was shown for intraabdominal free gas (κ = 0.76) and leakage of intraluminal contrast agent (κ = 0.76). Overall diagnostic performance in correctly identifying surgically confirmed leaks, as assessed by the area under the ROC curve, ranged from 0.76 to 0.86. Diagnostic performance was higher for all readers when intraluminal contrast agent was used and reached the anastomosis, with the exception of one reader, whose diagnostic performance remained unchanged.
Diagnostic performance of CT was highest when an intraluminal contrast agent was used. Meticulous and careful use of an intraluminal contrast agent is therefore important in this patient population.
本研究旨在评估 CT 在识别吻合口漏中的诊断性能。
这是一项针对接受肠手术且随后专门进行术后 CT 检查以调查吻合口漏的患者的研究。研究组包括经手术证实的吻合口漏患者（n = 59），对照组包括经再次手术或至少 6 个月无并发症临床随访证实无吻合口漏的患者（n = 48）。两位放射科医生和两位放射科住院医师独立对每位患者的 CT 检查进行评估，以确定一组预设成像预测因子的特定 CT 表现。计算每位读者的每个成像预测因子的敏感性和特异性，并使用 Cohen kappa 系数计算观察者间一致性。使用 ROC 曲线分析评估诊断性能。
最敏感的成像预测因子是腹腔游离液（95.3%）。腔内造影剂泄漏也是高度特异的成像预测因子（96.6%）。腹腔游离气体（κ = 0.76）和腔内造影剂泄漏的观察者间一致性较大（κ = 0.76）。ROC 曲线下面积评估的正确识别手术证实的漏诊的总体诊断性能范围为 0.76 至 0.86。当使用腔内造影剂并到达吻合口时，所有读者的诊断性能均较高，除一位读者的诊断性能保持不变。
当使用腔内造影剂时，CT 的诊断性能最高。因此，在该患者人群中，仔细、谨慎地使用腔内造影剂非常重要。
