射精管-精囊区梗阻所致无精子症的MRI诊断

MR diagnosis of obstructive azoospermia caused by ejaculatory duct-seminal vesicle lesions

目的:探讨射精管-精囊区梗阻所致无精子症的MRI表现,提高对该区域病变的认识。方法:回顾性分析本院2010年1月-2018年12月在我院诊断为射精管-精囊区梗阻所致无精子症的54例患者的临床及影像资料,其中先天性病变30例、继发性病变24例。所有患者行盆腔MR平扫及增强扫描。结果:射精管-精囊区各种来源的囊肿MR信号基本相仿:在T1WI上呈低～等信号,T2WI上呈高信号,囊内可有出血,增强扫描囊内容物无明显强化。鉴别主要依靠定位、形态及相关表现。先天性病变:①精囊发育不全或不发育(12例),表现为双侧精囊缺如,双侧精囊体积缩小,单侧精囊体积缩小而对侧精囊缺如;②前列腺苗勒管囊肿(6例),表现为位于前列腺后正中部、双侧精囊之间的精阜区、矢状面或冠状面图像上呈倒置的水滴状的的囊性病灶,边缘光整;③Zinner综合征(5例),为一侧肾脏缺如合并同侧精囊囊肿;④常染色体显性遗传性多囊肾(ADPKD)合并双侧精囊囊肿(7例),表现为双侧多囊肾(1例合并多囊肝)伴有双侧精囊囊肿。继发性病变:①精囊炎(14例),可合并或不合并精囊囊肿,表现为单侧或双侧精囊扩张、形态大小不一,扩张的精囊囊壁增厚;②射精管囊肿(10例),为前列腺部后部的精阜区偏一侧且长轴方向与射精管走行一致的、边缘光整、边界清晰的囊性病灶。结论:射精管-精囊区病变所致的梗阻性无精子症的病种多样、复杂,通过其特征性的MRI表现和合适的检查方法,有助于正确诊断该区域的病变。

Objective: To investigate the MR findings of obstructive azoospermia caused by ejaculatory duct-seminal vesicle lesion,and improve the understanding. Methods: The clinical and MRI data of 54 patients confirmed with obstructive azoospermia in our hospital from January 2010 to December 2018 were retrospectively analyzed.All patients underwent abdomino-pelvic MR examination including no-enhanced and enhanced MRI. Results: Obstructive azoospermia caused by ejaculatory duct-seminal vesicle lesions included congenital diseases (30 cases) and secondary diseases (24 cases).The cystic lesions in this region were similar on MRI,generally low-equal signals on T 1WI,high signals on T 2WI,and the contents of lesions were not enhanced.The diagnosis mainly depended on location,morphology and related clinical performance.Congenital lesions include:①seminal vesicle agenesis (n=12) presented as bilateral seminal vesicle absence,bilateral seminal vesicle volume reduction,unilateral seminal vesicle volume reduction and contralateral seminal vesicle absence.②Mullerian duct cyst of the prostate (n=6) presented as a smooth cystic mass with an inverted droplet-like margin between the posterior center of the prostate and bilateral seminal vesicles on sagittal or coronal plane.③Zinner syndrome (n=5) presented as a unilateral absence of kidney with ipsilateral seminal vesicle cyst.④Autosomal dominant hereditary polycystic kidney (ADPKD) with bilateral seminal vesicle cysts (n=7) presented as bilateral polycystic kidney (1 case with polycystic liver) and bilateral seminal vesicle cysts.Secondary lesions included:①seminal vesicle inflammation with or without seminal vesicle cysts (n=14) manifested as unilateral or bilateral seminal vesicle dilatation in different shapes and sizes,with thicken wall;②Ejaculatory duct cyst (n=10) manifested as a cyst with smooth margin and clear margin,located in the seminal region of the posterior part of the prostate and its long axis was consis- tent with ipsilateral ejaculatory duct. Conclusion: Obstructive azoospermias caused by lesions located the ejaculatory duct-seminal vesicle region are various and complex,and MR manifestations and appropriate examination can help us make correct and complete diagnosis.