胰岛素瘤的CT诊断

目的分析胰岛素瘤的CT表现,提高术前诊断能力。方法回顾性分析2005年至2012年期间在我院经手术病理证实的11例胰岛素瘤患者的CT图像及临床表现,CT扫描包括平扫、增强扫描动脉期及静脉期。结果本组患者主要临床表现为反复发作性饥饿、头晕、心慌、昏迷,其中4例发作期间生化检查显示血糖降低而胰岛素仍升高。11例患者病灶分布如下:胰头3例,胰颈2例,胰体2例,胰尾4例,病灶大小0.9-2.0cm不等,边界清晰。1例病灶含钙化,CT平扫及增强扫描均呈高密度;另外10例病灶平扫呈等或稍低密度,增强扫描呈等或高密度,仅动脉期病灶与正常胰腺实质CT值的配对样本t检查有统计学差异(P<0.05)。11例中1个病灶因平扫及增强扫描均呈等密度而术前漏诊,其余10术前均正确诊断。结论胰岛素瘤的CT表现有一定特征性,在CT增强扫描动脉期大多能显示并可靠诊断,但极少数等或稍高强化病灶容易漏诊,术前诊断应谨慎。

CT Diagnosis of Insulinoma

Purpose To analyse computed tomographic（CT） images of insulinoma, and to improve its preoperative CT diagnosis. Methods Clinical manifestations and CT images of 11 patients with insulinoma which were proved by surgery pathology from 2005 to 2012 were retrospectively analysed. All patients had plain and enhanced CT scan including aterial and venous phases. Results All cases had recurrent hunger, dizziness, palpitation and coma. The biochemical examination of 4 cases who were during the onset showed that blood sugar decreased and insulin elevated meanwhile. 11 lesions were located as follows： 3 in the pancreatic head, 2 in the pancreatic neck, 2 in the pancreatic body, 4 in the pancreatic tail. All lesions of 11 cases were well-circumscribed with the size from 0.9cm to 2.0cm. One lesion containing calcifications showed high-density on plain and enhanced CT scan. The other 10 lesions showed iso- or slightly lower-density on plain scan, and showed isoor higher density on enhanced scan. Only in arterial phase, paired t-examination of the lesions with normal pancreatic CT values were significantly different （P 〈 0.05）. One lesion was misdiagnosed before surgery because of its iso-density on plain and enhanced scan, but all other 10 cases were diagnosed correctly. Conclusion Insulinoma has certain characteristic CT findings, on the arterial phase of enhanced CT scan it can be diagnosed reliably, but very few lesions with iso-or slightly higher-enhancement may be misdiagnosed, preoperative diagnosis should be cautious.