Objective:To evaluate the accuracy of MR Urograph y (MRU)in demonstrating the location and cause of urinary tract obstruction and to contrast it with IVU,retrograde urography,CT,US, surgical operation and patholo gy.

• 目的 :通过磁共振尿路造影 (MRU)与静脉尿路造影 (IVU )、逆行尿路造影、电子计算机断层扫描 (CT)、灰阶超声 (US)及手术、病理学检查对照研究 ,评估 MRU对尿路梗阻部位、原因的临床应用价值。