From the Departments of Radiology (S.K.J., J.M.L., I.J., J.K.H.), Surgery (J.Y.J.), and Pathology (K.B.L.), Seoul National University Hospital, 101 Daehangno, Jongno-gu, Seoul 03080, Korea; Department of Radiology (J.M.L., J.K.H.) and Division of Gastroenterology, Department of Internal Medicine, (J.K.R.), Seoul National University College of Medicine, Seoul, Korea; Department of Radiology, Chung-Ang University Hospital, Seoul, Korea (E.S.L., H.J.P.); and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea (J.K.H.).
Radiology. 2017 Jul;284(1):77-87. doi: 10.1148/radiol.2016160586. Epub 2017 Jan 13.
Purpose To determine useful magnetic resonance (MR) imaging features to differentiate nonhypervascular pancreatic neuroendocrine tumors (PNETs) from pancreatic ductal adenocarcinomas (PDACs). Materials and Methods The institutional review board approved this retrospective study and waived the informed consent requirement. Seventy-four patients with surgically confirmed PNETs and 82 patients with PDACs who underwent gadobutrol-enhanced MR imaging were included. Two radiologists independently evaluated the morphologic characteristics and temporal enhancement patterns of each tumor. Quantitative analysis, including measurement of tumor size, maximal upstream parenchymal thickness (MUPT), contrast-to-noise ratio, and apparent diffusion coefficient values, was performed. Uni- and multivariate logistic regression analyses were performed to identify relevant features to differentiate between PNETs and PDACs. Results On the basis of arterial enhancement, 38 PNETs (51%, 38 of 74) were hypervascular and 36 PNETs (49%, 36 of 74) were nonhypervascular. At MR imaging, nonhypervascular PNETs showed significantly higher frequencies of a well-defined margin, portal hyper- or isoenhancement, and MUPT of 10 mm or greater but lower frequencies of ductal dilatation, vascular invasion, and peripancreatic infiltration when compared with PDACs (P < .05 for all). At multivariate analysis, a well-defined margin and portal hyper- or isoenhancement were independent significant differentiators of PNETs from PDACs (odds ratio, 20.3 and 16.1, respectively). When applying the criteria of a well-defined margin and portal hyper- or isoenhancement, 64% of sensitivity and 99% of specificity were observed for the differential diagnosis of PNETs from PDACs. Conclusion A well-defined margin and hyper- or isoenhancement in the portal venous phase are useful MR imaging features that are more common in nonhypervascular PNETs and may help discriminate nonhypervascular PNETs from PDACs. RSNA, 2017 Online supplemental material is available for this article.
目的 旨在确定有助于鉴别胰腺神经内分泌肿瘤（PNET）与胰腺导管腺癌（PDAC）的磁共振成像（MRI）特征。
材料与方法 本回顾性研究经机构审查委员会批准，并豁免了知情同意书的要求。共纳入 74 例经手术证实的 PNET 患者和 82 例 PDAC 患者，均行钆布醇增强 MRI 检查。两名放射科医师独立评估了每个肿瘤的形态特征和时间增强模式。进行了定量分析，包括测量肿瘤大小、最大上游实质厚度（MUPT）、对比噪声比和表观扩散系数值。采用单变量和多变量逻辑回归分析来确定有助于鉴别 PNET 和 PDAC 的相关特征。
结果 根据动脉期增强表现，38 例 PNET（51%，38/74）为富血供，36 例 PNET（49%，36/74）为乏血供。MR 成像上，乏血供 PNET 具有更清晰的边界、门静脉高或等增强及 MUPT 为 10mm 或更大的频率更高，而具有胰管扩张、血管侵犯和胰周浸润的频率更低（所有 P 值均<.05）。多变量分析显示，边界清晰和门静脉高或等增强是 PNET 与 PDAC 鉴别的独立显著因素（比值比分别为 20.3 和 16.1）。应用边界清晰和门静脉高或等增强的标准，对 PNET 与 PDAC 的鉴别诊断，其灵敏度为 64%，特异度为 99%。
结论 边界清晰和门静脉期高或等增强是有用的 MRI 特征，在乏血供 PNET 中更为常见，有助于鉴别乏血供 PNET 与 PDAC。
美国放射学会，2017 年
在线补充材料可供本文参考。
