目的　评价CT扫描在原发性肠系膜占位性病变定位诊断中的价值。方法　 3 5例经CT检查并手术病理证实的原发性肠系膜占位性病变 ,分析其CT定位征象。结果　CT定位正确率 62 .9% ;阳性预测值 78.6%。有助于定位的征象包括 :(1)病灶与肠管关系密切 ,病灶周围有肠管绕行且绕行的肠管位置较恒定 ,而管腔内一般无充盈缺损征 ,本组 2 5例 ;(2 )腹膜后主要脏器受前方病灶压迫而变形、轴位旋转 ,本组 15例 ;(3 )病灶与腹膜后脏器之间及与腹壁之间存在脂肪间隙 ,本组 11例 ;(4 )病灶后缘压迫腹部大血管根部或病灶后缘有大血管包绕现象 ,本组 9例。病灶较大CT定位正确率较低。结论　CT扫描对原发性肠系膜占位性病变的定位诊断有重要价值。结合多种检查结果及临床表现有助于提高诊断正确率 Objective To evaluate the value of CT scan in the diagnosis of primary mesentery-space-occupying lesions. Methods Twenty-five cases of primary mesentery-space-occupying lesions confirmed by CT examination and surgical pathology were analyzed. Their CT features were analyzed. Results The accuracy of CT localization was 62.9% and the positive predictive value was 78.6%. Symptoms that may help to locate include: (1) the lesion is closely related to the intestine; the bowel around the lesion is more circumscribed and the location of the bowel is more constant; however, there is usually no filling defect in the lumen, which is 25 in this group ) After retroperitoneal major organs by the front of the oppression of the deformation and axial rotation, the group of 15 cases; (3) between the lesion and retroperitoneal organs and the abdominal wall between the fat gap, the group of 11 patients; (4) Margins of the lesion oppression of the great vessels of the abdomen or the posterior margin of the great vessels around the phenomenon, the group of 9 cases. Lesions larger CT positioning accuracy is lower. Conclusion CT scan has important value in the localization diagnosis of primary mesentery space-occupying lesions. Combined with a variety of test results and clinical manifestations contribute to improve the diagnostic accuracy