多层螺旋CT诊断恶性胃肠道间质瘤

目的：探讨多层螺旋CT（MSCT）诊断恶性胃肠道间质瘤（GIST）。方法：回顾性分析经手术及病理症实的27例恶性GIST的多层螺旋CT表现。全部病例均作平扫及增强双期扫描，并作多平面重建后处理。结果：肿瘤来源于胃11例，小肠9例，结肠5例，肠系膜2例；肿瘤横径4．2～22cm。边缘清晰12例，边缘不清15例。肿瘤形态多不规则，19例可见分叶。平扫病灶密度不均匀，增强扫描动脉期呈中度至明显强化，静脉期呈持续性强化。病灶内部可见多数大小不等的坏死区，9例呈囊实质性改变。合并肝脏转移4例，肺部转移1例，淋巴转移2例。本组定位准确率为85．2％（23／27），定性准确率77．8％（21／27）。结论：多层螺旋CT增强双期扫描、轴面结合多平面重建图像对恶性GIST的诊断有重要价值。

Value of Multi-slice CT in Diagnosis of Malignant Gastrointestinal Stromal Tumors

Objective：To investigate the value of multi-slice CT （MSCT） in the diagnosis of malignant gastrointestinal stromal tumors （GIST）. Methods：MSCT images of 27 cases of malignant GIST proved by surgery and pathology were retrospectively analyzed. Both plain and enhanced CT scans were performed and multiplanar reconstructions were made in all cases. Results： The lesions originated .from the stomach （n = 11 ）, small intestine （n= 9）, colon （n = 5）, and mesentery （n 2）. The transverse diameters of mass were 4.2 - 22cm, the edges were well-defined （ n = 12）, or poorly-defined （ n = 15 ）. The masses were mainly irregular in shape,lobulated in 19 cases. The lesions showed mainly heterodensity on plain scans, moderate to marked enhancement in arterial phase and durative enhancement in venous phase. Cystic necroses were observed in all the lesions, 9 cases were cystic and solid mixed masses. Hepatic metastases （n= 4）, pulmonary metastasis （n= 1）, lymphatic metastases （n= 2） were detected. The accuracy rate of MSCT diagnosis for location and pathologic features of GISTs were 85.2% （23/27） and 77. 8% （21/27）. Conclusion： Two-phase MSCT examination and axial images combined with multiplanar reconstruction images have important value for diagnosis of GIST.