胃间质瘤CT表现

Study on CT findings of gastric stromal tumors

目的探讨胃间质瘤（GST）的CT特征。方法回顾性分析经手术病理和免疫组织化学证实，且均行螺旋CT平扫及三期增强扫描的GST46例，总结本病的CT征象。并采用四格表卡方检验对43例单发不同直径GST的形态、生长方式、坏死及强化方式结果进行统计学分析。结果46例中，单发43例，多发3例。43例单发GST中，发生于胃体24例、胃底16例、胃窦3例。GST具有沿胃壁的垂直方向生长，肿瘤瘤体大但附着点较局限的生长特点。瘤体直径≤5cm者14例，形态规则10例，强化后密度均匀10例，有中心坏死者4例，呈腔内生长7例、腔外生长5例、腔内外同时生长2例；瘤体直径〉5cm者29例，形态不规则24例，强化后密度不均匀27例，有中心坏死者24例，呈腔内生长5例、腔外生长9例、腔内外同时生长15例。不同直径GST的形态、生长方式、坏死及强化方式差异均有统计学意义（P〈0．05）。43例单发GST中，实质密度不均匀强化31例、均匀强化12例。门静脉期及延迟期的强化高于动脉期，门静脉期的强化明显而持续。5例表现为不均匀间隔状强化，4例表现为动脉期即呈明显强化，动脉期CT值可达60HU。结论螺旋CT能准确显示GST的部位、形态、大小，并对临床早期诊断和治疗具有重要参考价值。

Objective To investigate CT findings in gastric stromal tumors（GST）. Methods Both plain and enhanced spiral CT findings in 46 cases with gastric stromal tumor were retrospectively analyzed. In all patients, diagnosis was confirmed with immunohistochemical markers. CT features were retrospectively studied and summarized. Statistical analysis of the shape, growth pattern, necrosis and enhancement patterns was performed with x^2 test in 43 cases with single gastric stromal tumor. Results Of the 46 GST patients, 43 patients had single GST and multiple GST was detected in 3 cases. In the 43 cases with single GST, tumors were found in the gastric body in 24 cases, gastric fundus in 16 cases, and in the gastric antrum in 3 cases. GST mostly grow along the vertical plane of gastric wall, with a large size but local attachment. The tumor size was less than 5cm in diameter in 14 cases. Of them, ten cases had a regular shape, 10 cases showed homogeneous enhancement, and 4 cases exhibited central necrosis, 7 tumors showed intra-luminal growth and 5 tumors showed extra-luminal growth, while the other 2 cases involved both intra and extra lumina. Twenty-nine eases had tumors larger than 5era in diameter. Of them, 24 cases had irregular shape, 27 cases showed inhomogeneous enhancement, 24 cases had central necrosis,5 tumors showed intra-luminal growth and 9 tumors showed extra-luminal growth, while 15 cases involved both intra and extra lamina. The tumor size of GST closely was related to the shape, growth pattern, necrosis and the inhomogeneous enhancement patterns of the GST （ P 〈 0. 05 ）. The enhancement of the tumor was more intense in venous phase and delayed phase. Five cases showed septal enhancement, 4 tumors exhibited marked enhancement in arterial phase with up to 60 HU. Conclusions CT can precisely display the location, shape and size of gastric stromal tumors. It is very helpful to provide useful information for early diagnosis and evaluation.