中肾管囊肿的CT与MRI诊断

CT and MRI diagnosis of mesonephric duct cysts

目的:通过回顾分析手术病理证实的中肾管囊肿的CT或MRI表现,提高中肾管囊肿CT与MRI的影像诊断水平。方法:回顾分析25例手术病理证实的中肾管囊肿的CT或MRI表现,5例行CT平扫加增强,21例行MRI平扫加增强,其中1例同时行CT和MRI平扫加增强。结果:本组病例全部为女性,单发23例,多发2例,位于输卵管系膜内19例,其中双侧2例;子宫正后方1例,腹膜后3例,下腹部2例。CT表现为圆形或卵圆形,低密度薄壁囊性肿块,边界清楚,1例腹膜后中肾管囊肿壁见多发钙化并右肾下垂、旋转不良、右侧输尿管异位;MRI表现为长T1长T2薄壁囊性肿块,1例腹膜后中肾管囊肿后壁可见一小囊;增强扫描,4例位于输卵管系膜内中肾管囊肿表现为囊壁部分弧线状强化,其余病例囊壁及囊内未见强化。结论:中肾管囊肿有其典型的发病部位,结合临床,CT或MRI可以提示中肾管囊肿的诊断,显示钙化方面CT优于MRI,显示病灶囊变结构及与周围结构之间关系,MRI检查优于CT。

Objective：To retrospectively analyze the CT or/and MRI findings of mesonephric duct cysts which were surgically and pathologically proved in order to to enhance the understanding and imaging diagnosis of mesonephric duct cysts by using CT and MRI.Methods：Retrospective analysis of the CT or MRI findings in twenty-five cases with mesonephric duct cysts confirmed by surgery and pathology were performed.Among those cases,5 underwent routine precontrast and postcontrast CT scanning,and 21 cases underwent precontrast and postcontrast MRI.Thus,there was 1 case performed with both CT and MRI.Results：All the patients were female.A single lesion was detected in 23 cases while multiple lesions in 2 cases.The lesions were located in the fallopian tube line membrane（19 cases,2 with bilateral lesions）,posterior to the uterus（1 case）,in retroperitoneal space（3 cases）,and in the lower abdomen（2 cases）.Mesonephric duct cysts were manifested as round,oval thin-walled cystic masses with clear margins on CT.The cyst wall with multiple calcifications as well as right renal ptosis,malrotation,and ectopic ureter were found in one particular retroperitoneal case.MRI showed thin-walled cystic masses with long T2 and T1 signal intensity.After administration of the contrast agents,4 cases had curve-shaped wall enhancement.The remaining cases had no enhancement.Conclusion：The diagnosis could be suggested based on CT and MRI findings for the mesonephric duct cysts with typical locations while combining the clinical features.In respect of visualizing the calcifications,CT is better than MRI.However,MRI is the imaging modality of choice to delineate the relationship between the cystic lesion and the surrounding structures.