胃间质瘤的CT和MRI诊断

目的:探讨胃间质瘤的CT和MRI的表现,以提高诊断正确率。材料和方法:回顾性分析13例经病理学及免疫组化证实的胃间质细胞瘤患者的临床资料和CT、MRI表现。13例均行CT平扫和增强扫描,其中4例行MRI平扫和增强扫描。结果:肿瘤均为单发,腔内型3例,腔外型6例,哑铃型4例,圆形或类圆形9例,分叶形4例,直径3.0~10.4cm,平均7.5cm。CT平扫示肿瘤呈均匀等密度3例,肿块周边呈等密度,中间呈略低密度或低密度9例,呈高、低、等混杂密度1例。增强扫描示3例呈中度明显增强,10例中度不均匀增强,以静脉期明显。MRI平扫示1例肿块信号均匀,3例肿块信号不均匀,增强扫描肿块信号均匀或不均匀增强。病理检查10例恶性,3例良性。结论:胃间质瘤CT、MRI具有一定的特征性表现,对诊断有一定的价值,但不能定性,确诊需要依靠电镜检查和免疫组化。

CT and MRI Diagnosis of Gastric Stromal Tumor

Purpose : To evaluate CT and MRI features of gastric stromal tumor and improve its diagnostic accuracy. Materials and Methods: Clinical data and CT, MRI findings were analyzed retrospectively in 13 cases with pathological and immunohistoche mical comfirmation. Non-contrast and contrast CT scan were done in all cases .Non-enhaned and enhaned MRI were performed in 4 cases. Results: All the tumors were solitary lesion,and intraluminal pattern(n=3),exophytic pattern(n=6),dumbbell pattern(n=4).Round mass was found in 9 cases,while the mass was lobulated in 4 cases. The tumoral size was 3.0~10.4cm,7.5cm in average.On plain CT scans,the tumors showed homogeneous isodensity(n=3),or low-density centrally with isodensity peripherally(n=9),or mixed density(n=1).On enhanced CT scans,moderate or marked enhancement was seen in 3 cases, moderate and inhomogenous enhancement was seen in 10 cases,which was best visualized in venous phase. On MRI one case presented homogeneous signal intensity, 3 cases presented inhomogeneous signal intensity,and homogeneous or inhomogeneous enhancement.10 cases were malignant and 3 cases was benign. Conclusion: Gastric stromal tumor has special CT and MRI features which may play a role in the correct dianosis, but that is not comfirmatory, the final diagnosis is provided only by electron microscopic examination and immunohistoche mical comfirmation.