恶性胃间质瘤的CT诊断

目的探讨多层螺旋CT（MSCT）诊断恶性胃间质瘤的价值。方法回顾性分析经手术及病理证实的21例恶性胃间质瘤的多层螺旋CT表现。结果肿瘤来源于贲门胃底部12例，胃体部6例，胃窦部3例。腔外型4例，腔内型5例，腔内外型12例。肿瘤直径4．1～21cm。肿瘤呈圆形、椭圆形4例，呈分叶状、不规则状17例。平扫CT表现：肿块密度不均匀，肿块内见有大小不等、形态不一的低密度影；增强CT表现：动脉期肿瘤实性部分呈轻中度强化，静脉期持续强化。6例胃腔面侧出现溃疡。3例肿瘤邻近胃黏膜不规则、毛糙，增强CT扫描黏膜不连续，不均匀强化。CT显示肿块边缘不清7例，肿块边缘清晰13例。合并肝脏转移1例，侵犯肝1例，侵犯腹膜2例。本组定位准确率为90．5％（19／21），定性准确率为81．0％（17／21）。结论多层螺旋CT对恶性胃间质瘤的诊断具有重要价值。

CT Diagnosis on Malignant Gastric Stromal Tumor

Objective To investigate the value of multi-slice CT （MSCT） in the diagnosis of malignant gastric stromal tumors. Methods MSCT images of 21 cases of the gastric stromal tumors proved by surgery and pathology were retrospestively analyzed. Results The lesions originated from cardia and fundus of stomach in 12 cases , body of stomach in 6 cases and Stomach antrum in 3 cases, malignant stromal tumors in all the patients could be divided into extro-cavity in 4 cases, intra-cavity in 5 cases and mixed in 12 cases. The diameters of mass were 4.1 to 21cm. The masses were circular or elliptical in 4 cases, and lobulated or irregular in 17 cases, in shape. The lesions showed heterodensity, and irregular size, edges poorly-defined low density in the masses on plain scans. The lesions in solid masses were mild to moderate enhancement in arterial phase and durative enhancement in venous phase. The lesions were ulcer on gastric cavity in 6 cases, other 3 cases whose the tumors adjacent mucosa were irregula, rough, and not continuous, inhomogeneous enhancement on enhanced CT scans. The tumors edges poorly-defined in 7 cases and tumors edges defined in 13 cases. Hepatic metastases in 1 case, hepatic invasion in 1 case and peritoneal invasion in 2 cases were detected. The accuracy rate of MSCT diagnosis for location and pathologic features of malignant stromal tumors were 90.5% （ 19/21 ） and 81.0% （ 17/21 ）. Conclusion MSCT has important value for diagnosis of malignant stromal tumors.