排泄性磁共振尿路成像在泌尿系疾病诊断中的价值

目的:探讨对比增强磁共振尿路成像(排泄性MRU)在诊断泌尿系疾病方面的价值.方法:选择经手术病理和影像学检查证实的泌尿系结石20例、肾盂旁囊肿6例、肾盏憩室1例、膀胱憩室3例和输尿管移行细胞癌4例,均先行磁共振尿路成像(常规MRU),然后增强扫描后延迟至5、10和20 min行排泄性MRU,显示不良者4 h后再扫描一次.将两者源图像分别进行最大强度投影(MIP)重组,并分别独立诊断,对两者结果进行对比分析.结果:排泄性MRU尿路显示清楚 5 min 5例,10 min 25例,4 h 4例.两者定位诊断符合率均为100%.排泄性MRU均能作出准确定性诊断,常规MRU准确定性诊断分别为泌尿系结石17例(17/20)、肾盂旁囊肿2例(2/6)、膀胱憩室3例(3/3)、输尿管移行细胞癌2例(2/4).结论:排泄性MRU能清楚显示尿路形态变化及、排泄功能,有利于尿路疾病的诊断.

Diagnostic Value of Excretory MR Urography in Urinary Tract Diseases

Objective:To study the diagnostic role of contrast-enhanced MRI of urinary tract(excretory MR urography)in urinary tract diseases.Methods:A series of cases with surgically or pathologically and imageologically proven urinary tract diseases,including 20 cases of urinary tract calculi,6 cases of renal para-pelvic cysts,1 case of renal calyx diverticulum,3 cases of urinary bladder diverticulum and 4 cases of ureter transitional cell carcinoma,was enrolled in this study.In all of the cases,conventional MR urography was initially performed and then contrast enhanced excretory MR urography was undergone with time delays of 5,10 and 20 mins respectively.In some cases with unsatisfactory excretory MR urograms,delayed scans were performed 4 hours after injection of the contrast agent.From the source images and with MIP technique,reconstructed MR urograms of the conventional and enhanced scans of all the cases were obtained and the diagnoses of the cases were independently and respectively made on the bases of the relative images.The diagnostic results were comparatively evaluated.Results:Clear demonstration of urinary tract was shown on excretory urographic scans at 5 min delay(n=5),at 10 min delay(n=25)and at 4 hr delay(n=4)respectively.Accuracy rates of lesion localization with the 2 different scanning techniques were both 100%.Accurate specific diagnoses were all made with excretory MR urographic images,while with conventional MR urographic images,17 cases of urinary calculi(17/20),2 case of renal para-pelvic cysts(2/6),3 cases of urinary bladder diverticulum(3/3)and 2 cases of ureter transitional cell carcinoma(2/4)were accurately diagnosed.Conclusion:Excretory MRU was not only capable of clearly demonstrating the morphological changes of lesions,but also providing the excretory functions of the urinary tract,therefore,it was helpful in the diagnosis of urinary tract diseases.