[RARE urography in pelvic tumors: diagnostic ranking and comparison with intravenous pyelography]

To examine if RARE urography may replace conventional intravenous urography in patients with suspected urinary obstruction in pelvic tumours.In a prospective trial on 120 patients with pelvic tumours scheduled for operation, biplanar RARE urography was performed and compared to conventional intravenous urography and ultrasound findings.In 30 out of 120 patients an ureteric obstruction was diagnosed by ultrasound. Sensitivity of RARE urography for obstruction was 98% as compared to 60% in conventional intravenous urography. In 12 patients additional retrograde cystoureterography showed a sensitivity of 83%. Specificity of RARE urography and intravenous urography was 100%. In combination with axial MR tomography RARE urography yielded a more precise localisation of the site of obstruction and the underlying cause (98%) as compared to conventional urography (60%) and ultrasound (56%).By use of RARE urography urinary obstruction can be reliably demonstrated or ruled out. Combining RARE urography with tomographic MR imaging allows the precise depiction of the site of the obstruction and may demonstrate the underlying pathology.