儿童胰腺实性假乳头状瘤的MRI表现

Appearance of children solid pseudopapillary neoplasm of the pancreas on MRI

目的分析儿童胰腺实性假乳头状瘤(SPN)的MRI资料并探讨其MRI特征。方法回顾性分析11例经手术病理证实为儿童胰腺SPN的MRI平扫及增强影像资料,其中男3例,女8例,平均年龄(10.6±2.74)岁。观察肿瘤平扫和增强MRI的信号特征及强化方式;在扩散加权成像(DWI)上观察肿瘤是否扩散受限,并测量病变的ADC值;通过MR胆胰管成像(MRCP)观察肝胆管、胰管是否受压梗阻。结果11例均为单发病灶,5例位于胰头部,2例位于胰腺头颈交界处,4例位于胰尾部。MRI平扫,病灶呈T1WI等低信号,T2WI高信号;增强T1WI上无强化或轻度强化。病灶内可见出血,T1WI上呈斑片状高信号,增强扫描后无强化。DWI上,病灶呈不均匀高信号,平均ADC值为(1.16±0.34)×10^(-3)mm^(2)/s。4例合并胰腺炎,MRCP显示胰管扩张,肝门部肝管或胆管扩张。结论儿童胰腺SPN在MRI上具有边界清晰、DWI扩散受限、增强后无强化或轻度强化的影像特征,结合临床资料可明确诊断。

Objective To analyze the MRI data of solid pseudopapillary neoplasm(SPN)of the pancreas in children and explore its MRI features.Methods MRI plain scan and enhanced scan data of 11 children with solid SPN confirmed by surgery and pathology were retrospectively analyzed.There were 3 males and 8 females,with an average age of 10.6±2.74 years.The signal characteristics and enhancement patterns of tumor after plain scan and enhanced scan were observed.DWI was used to observe whether the diffusion of water molecules was restricted in the tumors,and ADC values of the lesions were measured.Magnetic resonance cholangiopancreatography(MRCP)was used to observe whether the hepatobiliary duct and pancreatic duct were obstructed.Results All of the 11 cases had single lesion,5 tumors were located at the head of the pancreas,2 tumors were located at the junction of the head and neck of the pancreas,and 4 tumors were located at the tail of the pancreas.On MR plain scan,the lesion showed iso-or hypo-intensity on T1WI and hypersignal on T2WI.No enhancement or mild enhancement on T1WI.Tumors presented hemorrhage,showing patchy hypersignal on T1WI,but no enhancement on enhanced MRI.The lesions showed heterogeneous hyper-intensity on DWI,and the average ADC value of lesions was 1.16±0.34×10-3 mm2/s.Four tumors were combined with pancreatitis.MRCP showed dilatation of the pancreatic duct and dilatation of the hepatic duct or bile duct in the hilar.Conclusion Children SPN of the pancreas is characterized by clear boundaries on MRI,easy bleeding,restricted diffusion on DWI,and no enhancement or mild enhancement on enhanced scan.Combining with clinical data,definite diagnosis of SPN can be made.