肝门周围游离气体征鉴别消化道穿孔价值的多排螺旋CT研究

目的 评价多排螺旋CT腹部扫描时肝门周围游离气体(periportal free air PPFA)征对于鉴别上下消化道穿孔的价值.方法 回顾性分析62例经外科手术证实的消化道穿孔患者的腹部CT影像片,包括上消化道穿孔35例及下消化道穿孔27例.当肝门周围有游离气体存在时,则定义为肝门游离气体(PPFA)征阳性.观察2组中PPFA征的差别并计算PPFA在诊断上消化道穿孔时的特异性、敏感性、阳性预测值、阴性预测值及准确率.结果 上消化道穿孔的35例患者中有33例患者具有PPFA征(占94%),但下消化道穿孔的27例患者中只有10例患者存在PPFA征(占37%),两者有明显差别(P<0.05).PPFA征对于诊断上消化道穿孔的敏感性、特异性、阳性预测值,阴性预测值以及准确率分别为94%(33/35),63%(17/27),77%(33/43),89%(17/19)和81%(50/62).结论 PPFA征对于鉴别上下消化道穿孔是有用的征象.

Gastrointestinal Perforation: The Value of the Periportal Free Air Sign on Multidetector Spiral Computed Tomography

Objective To evaluate the value of the periportal free air(PPFA) sign at computed tomography(CT) in distinguishing between upper and lower gastrointestinal(GI) tract perforation. Methods CT images of 62 patients with surgically proven GI tract perforation were retrospectively analyzed. 62 cases included upper and lower GI tract perforation in 35 cases and 27 cases,respective-ly. When there was free air in the periportal area,it was defined as positive periportal free air(PPFA) sign. The difference of PPFA sign in upper and lower GI tract perforation, and the sensitivity, specificity, positive predictive value, negative predictive value and ac-curacy of PPFA sign in diagnosing gastrointestinal perforation were analysed respectively. Results The PPFA sign was seen in 33 of 35(94%) patients with upper GI tract perforation,but only in 10 of 27 (37%) patients with lower GI tract perforation,there was sig-nificant difference between them(P<0.05). For diagnosis of super GI perforation with PPFA sign, the sensitivity, specificity, positive predictive value,negative predictive value and accuracy were 94% (33/35), 63%(17/27), 770%(33/43), 89%(17/19) and 81% (50/ 62), respectively. Conclusion The PPFA sign is a useful finding in distinguishing between upper and lower GI tract perforation.