多层螺旋CT诊断胃肠道间质瘤的价值

Diagnostic value of multi-slice CT in gastrointestinal stromal tumors

目的：探讨胃肠道间质瘤的多层螺旋CT（MSCT）影像学特点。方法收集7例经手术病理免疫组织化学证实的胃肠道间质瘤的临床资料进行回顾性分析。结果肿瘤直径4．8~21．3 cm，平均直径约9．5 cm。发生于胃4例，小肠3例；CT平扫肿瘤呈软组织密度，密度均匀3例，瘤内低密度坏死4例，瘤内钙化1例，边缘清楚7例，病变腔内侧面溃疡，气体进入瘤内1例；增强扫描时肿瘤实质区明显强化，CT增值在27~58 Hu，且静脉期高于动脉期。术后病理低恶性风险1例，中度恶性风险2例，高度恶性风险4例。免疫组织化学7例均显示CD117阳性。结论 MSCT能显示胃肠道间质瘤的病理学特征与周围组织的关系，对其定位和诊断有较高的价值，但对肿瘤的危险程度的预测有一定限度；肿瘤的大小和核分裂计数的多少是胃肠间质瘤危险程度的重要指标。

Objective To explore multi-slice CT （MSCT） imaging features of gastrointestinal stromal tumors （GIST）. Methods MSCT findings of 7 cases were retrospectively analyzed, diagnosed with GIST surgically and patho-logically and by immunohistochemistry. Results Among the 7 cases, 4 cases were located in stomach, 3 cases in small intestine. The diameter of the tumor ranged from 4.8 cm to 21.3 cm, The average diameter was about 9.5 cm. By non-contrast enhanced CT scan,the density of masses was equal to that of soft-tissue. The lesions were homogenous in 3 cases,hypo-dense necrosis was found in 4 cases, calcification was revealed in 1 case, well demarcated lesions were demonstrated in all cases. Tumor with deep intra-mural ulcers reselting gas entering into the mass was detected in 1 case. In the imagings by contrast enhanced scan,remarkable enhancement was seen in the parenchyma of the tumor with the CT value increasing from 27~58 Hu,while no enhancement was revealed in the necrosis and cystic area of the tumor. And venous phase enhancement was obviously higher than arterial phase in the tumor. As for the dangerous level of GIST, postoperative pathology showed 1 case was in the low dangerous risk, 2 cases was in the middle danger-ous risk and 4 cases were in the high dangerous risk,CD117 antibody was positive in all 7 cases. Conclusion MSCT can show some pathology features of GIST and the relationship of the tumor and surrounding tissue. MSCT is capable of precisely localizing the sites of GIST and is also very helpful in establishing the diagnosis of GIST. The size of tu-mors and the amount of karyokinesis plays an important role in judging the dangerous level of GIST.