CT和MRI对主胰管型胰腺导管内乳头状黏液瘤良恶性鉴别的价值

Distinguishing benign from malignant main duct intraductal papillary mucinous tumors of the pancreas by CT and MRI

目的 探讨影像学检查对主胰管型胰腺导管内乳头状瘤（MD-IPMN）诊断及其良恶性鉴别诊断的价值.方法 回顾性分析经手术病理证实的31例MD-IPMN患者的影像学资料.患者术前均行CT、MRCP、MR中的一种或两种以上检查.由两名医师观察病灶的影像学表现,进行影像学评分,鉴别病灶的良恶性.采用Bland-Altman分析评价两名医师结果的一致性.将病变的影像学评分与病理检查结果进行对照.绘制受试者工作特征（ROC）曲线,计算曲线下面积（AUG）,评价影像学检查测得的主胰管直径在MD-IPMN良恶性鉴别中的作用,并确定最佳诊断界值和敏感性、特异性.结果 31例MD-IPMN患者中低级别异型增生13例,中级别异型增生6例,高级别异型增生5例,癌7例;影像学正确诊断MD-IPMN为良性16例,恶性10例,余5例误诊.主胰管直径判断病变良恶性有临床意义,其鉴别良恶性的AUC为83.8％;最佳诊断界值为14.8 mm,敏感性66.7％,特异性100％.有无壁结节也可作为良恶性鉴别的影像学表现,但壁结节大小、病变累及主胰管的部位、胰腺实质萎缩及肝内外胆管扩张对良恶性的鉴别诊断价值不大.结论 影像学检查对MD-IPMN的诊断以及良恶性的鉴别都具有敏感性,对术前诊断和随访具有一定的临床价值。

Objective To evaluate the value of imaging studies in diagnosis and differentiating malignant from benign main duct intraductal papillary mucinous neoplasms （MD-IPMNs）.Methods The imaging studies of a total of 31 patients with MD-IPMNs confirmed by pathology after surgery was retrospectively reviewed.All patients underwent either CT,MR or MRCP.Two radiologists observed the lesions＇ imaging feature,and then the lesions was scored,and the differentiation between malignant and benign was made.The Bland Altman method was used for evaluation of inter-observer agreement.The score of the lesions was compared with the pathological results.Finally,a ROC curve was used to calculate AUC,and to evaluate the role of the maximum diameter of the main pancreatic duct （MPD） obtained by imaging studies in differentiation of malignant and benign IPMNs,and to determine the best cut-off point,and sensitivity,specificity.Results Histological analysis revealed low grade dysplasia in 13 patients,middle grade dysplasia in 6 and high grade dysplasia in 5,and adenocarcinoma in 7.Imaging studies suggested benign lesions in 16,malignant lesions in 10 patients and disdiagnosis in 5.The inter-observer agreement on major imaging features was good.The maximum diameter of the MPD was clinically meaningful for distinguishing malignant from benign lesions,and the AUC was 83.8%,and the best cut-off value was 14.8 mm,the sensitivity and specificity was 66.7% and 100%.The presence of wall nodules could be an imaging feature for distinguishing malignant from benign lesions,but the size of nodules,location of nodules within pancreatic duct,the atrophy of pancreatic parenchyma,and dilated bile duct was not useful for differentiation.Conclusions The imaging studies are sensitive for diagnosis and differentiation between malignant and benign MD-IPMNs,and it is of clinical value for preoperative diagnosis and follow up.