胃肠道间质瘤的CT表现与诊断价值

Assessment of CT diagnosis of gastrointestinal stromal tumors

目的:回顾性分析胃肠道间质瘤(GIST)的CT表现特点,探讨CT对该肿瘤的诊断价值。方法:收集经手术和病理证实的胃肠道间质瘤30例,术前均行CT平扫及增强扫描检查。结果:肿瘤发生于胃部16例,小肠9例,结肠2例,肠系膜2例,食管1例。平扫:软组织肿块向胃肠腔内、外或同时向腔内外突出;肿块密度均匀;肿块周边呈等密度,中心呈略低密度或低密度,或呈高、等、低混杂密度。增强:轻度均匀强化,不均匀明显强化,或呈中心坏死囊变周边明显强化。30例GIST中,良性7例,肿块直径小于5 cm,边界清楚,多轻度均匀强化;恶性23例,肿块直径多大于5 cm,边界多不清,部分边缘见分叶状,22例肿块有坏死,其中4例见钙化,3例呈高、等、低混杂密度,8例出现转移灶。结论:CT检查对于GIST敏感性高,对肿瘤良、恶性的判断也很有价值,但对体积较大的GIST确定肿瘤组织来源较困难,需结合钡餐造影及内镜检查以提高定位的准确性。

Objective： To investigate the features of gastrointestinal stromal tumor（GIST） and assess the CT diagnosis of the tumor. Methods： Data of 30 cases of GIST examined with CT and contrast enhanced CT confirmed by surgery and pathology were studied retrospectively. Results： Of the location of the GIST, 16 cases in stomach, 9 cases in small intestine,2 cases in colon, 2 cases in mesentery, 1 case in esophagus. Features of plain CT of the GIST were ： the tumor masses bulged to the lumen of stomach or intestine or to the outside of the wall or both; the density of the tumor masses were homogeneous; isodensity presented on the outside parts, low or lower density presented in central parts ; density of patial masses were heterogeneous, presented hyperdensity, hypodensity and isodensity. Features of contrast enhanced CT of the GIST were： mild homogeneous enhancement, uneven marked enhancement, or marked enhancement on the surrounding of central cystic necrosis. Seven of the 30 cases of GIST were benign, the diameter of these masses was less than 5 cm, the borders were well circumscribed. Twenty-three of the 30 cases of GIST were malignant, the diameter of these masses was larger than 5 cm, the borders were obscure, partial masses had lobulations. 22 cases occurred necrosis, among them 4 cases with calcification, 3 cases were were heterogeneous, presented hyperdensity, hypodensity and isodensity; 8 cases occurred metastasis. Conclusion： CT examination for GIST has high sensitivity, has value for the determination of properties of benign and malignant. It＇s hard to find the histological origin of larger GIST with CT alone, combined with gastrointentinal barium contrast and endoscopy may improve positioning diagnosis.