胰岛素瘤的CT诊断及漏诊原因分析

目的：分析胰岛素瘤的 CT 表现,总结不典型胰岛素瘤的漏诊原因。方法回顾性分析18例经手术病理证实的胰岛素瘤的临床表现及 CT 图像,并对 CT 表现不典型的胰岛素瘤进行漏诊原因分析。结果10例胰岛素瘤行 CT 平扫,9例表现为等密度,1例为稍低密度,边缘见细线样包膜；18例行 CT 增强扫描,10例动脉期呈明显强化,其中6例门脉期呈等密度,4例密度稍高,延迟期10例均呈等密度；4例动脉期呈轻中度强化,其中2例门脉期仍稍高于胰腺,2例呈等密度,延迟期1例仍稍高于胰腺,3例等于胰腺；8例门脉期强化程度基本等同于胰腺,6例稍高或高于胰腺；13例延迟期均等于胰腺,1例延迟期仍高于胰腺。18例中3例极易漏诊,4例漏诊病例平扫及增强均与胰腺密度相近,后经其他影像学方法检出。结论CT 多期增强扫描应作为胰岛素瘤的首选检查方法。

Analysis of CT fingings and the causes of missed diagnosis of insulinoma

Objective To analyze CT findings of insulinoma,and to summarize the causes of missed diagnosis of nontypical insuli-noma.Methods Clinical and CT manifestations of 18 patients with 18 insulinomas were analyzed retrospectively which were proved by surgery and pathology,and the causes of the missed diagnosis of nontypical insulinoma were also summarized.Results 10 patients with 10 insulinoma underwent CT plain scan with isodensity in 9 and slightly lower density in 1 with thread-like capsule.Other 18 patients underwent enhanced CT scan,10 of whom showed obvious enhancement in arterial phase with isodentisy in 6 and slightly higher density in 4 in portal phase,and isodensity in 10 in delayed phase.4 lesions showed mild-to-moderate enhancement in arterial phase with slightly higher density than normal pancreas in 2 and isodentisy in 2 in portal phase,and slightly higher density than nor-mal pancreas in 1 and similar density to pancreas in 3 in delayed phase.In portal phase,the enhanced degree in 8 was similar to the pancreas,and that in 6 was slightly higher or higher than that of pancreas.In delayed phase,13 were similar to the pancreas and other 1 was higher than that.3 of 18 lesions were easily missed,and 4 lesions with missed diagnosis showed isodensity on plain CT and en-hanced CT,and were further detected by other imaging methods.Conclusion Multiphase enhancement CT scanning can be used as the first choice for the insulinoma.