无功能胰岛细胞瘤的CT和MRI诊断

CT and MRI Diagnosis of Nonfunctioning Islet Cell Tumor

目的:探讨无功能胰岛细胞瘤的CT和MRI诊断。方法:回顾性分析30例经病理证实的无功能胰岛细胞瘤的影像资料,良性24例,恶性6例;经CT扫描27例,MRI9例,其中6例同时行CT及MRI检查。结果:本组肿瘤直径2～20cm,平均8cm,≥8cm者16例(占53.3%)。16例(占53.3%)肿瘤呈囊性或囊实性,12例(40%)肿瘤内有较小变性坏死区,2例呈实性。12例(40%)肿瘤内有出血区,9例(30%)CT扫描见钙化影。24例CT和9例MRI增强扫描显示肿瘤内的实性部分明显强化。9例MRI的T1WI呈较低信号,T2WI呈明显高信号。结论:肿瘤体积较大、边缘规整伴变性坏死,增强扫描肿瘤实性部分明显强化以及出血、钙化是无功能胰岛细胞瘤较有特征的影像学表现。

Objective：To study the diagnostic value of CT and MRI on nonfunctioning islet cell tumor. Methods：Imaging findings in 30 patients with histopathologically proved nonfunctioning islet cell tumor were analyzed retrospectively. There were 24 benign cases and 6 malignant cases. Of the 30 cases,CT scanning was performed in 27, MRI in 9. Results： The mean size of these tumors was 8cm （from 2-20cm） ,and tumors of 16 cases （53.3%） were larger than 8cm in diameter. 16 cases （53.3%） showed cystic or heterogeneous masses with solid and cystic component,and 12 cases （40%） s.howed small necrosis. 12 cases （40%） contained hemorrhage within tumor,calcification was detected in 9 （30%） by CT. Solid part in tumor showed marked enhancement in 24 CT and 9 MRI by dynamic enhancement. Tumors showed low signal intensity on T1 W, and markedly high signal intensity on T2 W of MRI. Conclusion ： Larger size and regular-circumscription of tumor with necrosis or cystic degeneration, marked enhancement in solid part of tumor, hemorrhage and calcification are characteristic imaging features.