儿童小肠淋巴管扩张症三例CT及MRI影像特点分析

摘要

目的 探讨儿童小肠淋巴管扩张症(IL)的CT及MRI影像特点,提高影像学诊断水平.方法 回顾性分析浙江大学医学院附属儿童医院2016年1月—2017年6月经胃镜及病理检查证实并有完整影像资料的3例IL患儿的临床及影像资料,并复习相关文献.本组患儿1行腹部CT平扫+增强扫描,患儿2行腹部CT平扫+增强扫描及腹部MRI平扫检查,患儿3行腹部MRI平扫+增强扫描.结果 患儿1腹部CT平扫+增强扫描示上段空肠局部肠壁弥漫性增厚,增强后明显强化;肠系膜上动脉及其分支被条片状水样低密度影包裹,无强化.患儿2腹部CT平扫+增强扫描示肝脏体积明显增大,肝静脉增粗扩张;部分小肠局部肠壁增厚,增强后明显强化;肠系膜上动脉及其分支被条片状水样低密度影包裹,无强化.腹部MRI平扫示十二指肠、部分空肠肠壁增厚.重T2加权像(T2WI)的最大信号强度投影(MIP)重组图像显示腹膜后区及肠系膜区淋巴管广泛扩张,呈网状改变,近端胸导管扭曲扩张.患儿3腹部MRI平扫+增强扫描示后腹膜区、肠系膜上动脉及其分支周围呈团块状长T1、T2信号影,边界尚清,将肠系膜上动脉包埋,血管未见明显受压、变扁.重T2WI的MIP重组图像显示双侧腰干及其外周肠系膜区淋巴管广泛扩张,呈网状改变.结论 IL在重T2WI的MIP重组图像上表现为后腹膜区淋巴管广泛扩张,有一定特征性;结合腹部CT或MRI增强扫描,明确显示肠系膜上动脉及其分支被条片状无强化的水样低密度影包裹、局部肠壁增厚;可用于无创诊断IL.%Objective To investigate the CT and MRI manifestations of intestinal lymphangiectasis(IL) in children,improving the diagnostic accuracy of this disease by these two imaging techniques.Methods In this retrospective study,we enrolled 3 participants who received treatment in the Children's Hospital,Zhejiang University School of Medicine from January 2016 to June 2017.They were diagnosed with IL based on the results of gastroscopy,pathological examination and imaging examination.No.1 case underwent unenhanced CT scan and contrast-enhanced CT scan of the abdomen,No.2 case underwent unenhanced CT scan and contrast-enhanced CT scan of the abdomen as well as unenhanced MRI scan of the abdomen,and No.3 case underwent unenhanced MRI scan and contrast-enhanced MRI scan of the abdomen.We analyzed their clinical and imagining data and reviewed the related literature.Results No.1 case:part of the upper jejunal wall was diffusely thickened and obviously enhanced after enhancement.The superior mesenteric artery and its branches were covered with flaky and striped water-like low-density shadows,which were not enhanced after enhancement.No.2 case:unenhanced CT scan and contrast-enhanced CT scan showed that the volume of the liver increased significantly,and the hepatic veins dilated;part of the small intestinal wall was diffusely thickened and obviously enhanced after enhancement.The superior mesenteric artery and its branches were covered with flaky and striped water-like low-density shadows without enhancement.Abdominal unenhanced MRI scan showed that the duodenum and part of the jejunal wall were thickened,MIP reconstructed images of heavy T2WI showed that the lymphatics in retroperitoneal and mesenteric regions expanded extensively with reticular changes,and the proximal thoracic duct was twisted and dilated.No.3 case:the retroperitoneal region and the area around the superior mesenteric artery and its branches appeared as lump-shaped shadows of long T1 and T2 with clear boundary,the superior mesenteric artery was completely covered without significant pressed and flattened appearance.Moreover,the MIP reconstructed images of the heavy T2WI showed that the lymphatics in the bilateral waist areas and mesenteric region expanded extensively with reticular changes.Conclusion The extensive reticular lymphatic expansion in the retroperitoneal and mesenteric regions on the MIP reconstructed image of the heavy T2WI is the characteristic of IL.CT scan or contrast-enhanced MRI scan of the abdomen can be used for non-invasive diagnosis of IL,since either of them can clearly show superior mesenteric artery and its branches covered by flaky and striped water-like low-density shadows without enhancement and partly thickened small intestinal wall.