胃肠道间质瘤的CT和MRI分析

目的探讨胃肠道间质瘤（GIST）的CT和MRI表现。方法回顾性分析经病理证实的23例GIST的CT和MRI表现，其中18例行CT检查，5例行MRI检查。结果23例肿瘤中单发21例（发生于胃8例，小肠10例，结肠3例），胃肠道及其系膜多发2例。表现为类圆形或分叶状肿块，长径3cm至22cm，CT表现为平扫肿块密度欠均匀，多数有坏死、囊变，增强扫描实性部分强化，静脉期强化较动脉期更明显。MRI表现为平扫病灶T1WI低或稍低信号，信号不甚均匀，T2WI混杂信号，以高或稍高信号为主，并见长T1、短T2信号的包膜。增强扫描病灶实性部分不均匀强化，静脉期较动脉期显著，坏死、囊变区未见强化。2例包膜强化，3例包膜不强化。所有病例均未见肠梗阻。结论GIST的CT和MRI表现具有一定的特征性，具有较高的诊断价值。

Analysis of CT and MRI manifestations of gastrointestinal stromal tumor

Objective To evaluate the CT and MRI manifestations of gastrointestinal stromal tumor(GIST).Methods The CT and MRI manifestations of twenty-three cases with GIST,proved by pathology,were retrospectively analyzed,of which 18 cases and 5 cases underwent CT and MRI respectively Results Twenty-one of 23 cases had solitary masses(8 in stomach,10 in small intestine and 3 in colon).Multiple were 2 cases which were found in gastrointestinal tract and its mesentery.With CT,the tumors manifested non-homogeneous texture and round or phylloid shapes from 3 to 22 cm and cystic or necrotic changes could be seen.After contrast medium were injected,the parenchyma of tumors was intensified and enhancement was more obvious in the arterial phase than in the veinous one.With MRI,the tumors manifested low or slightly low signal and farraginous signal that were mainly high or slightly high on T1WI and T2WI respectively.Their envelopes appeared low signals on T1WI and T2WI.After contrast medium were injected,the parenchyma of tumors were intensified and enhancement was more obvious in the arterial phase than in the veinous one.The areas of cystic and necrotic changes were not intensified.The envelopes were intensified or not intensified.Ileus did not occur in all patients.Conclusion CT and MRI manifestations of GIST have some characteristics which is of great diagnostic value.