131I-hippuran renography for control of patients with ureterolithiasis.

The value of the 131I-Hippuran renography for control of patients with ureteroliathiasis was investigated in a consecutive series of 58 patients with radiologically verified unilateral ureteroliathiasis. Intravenous pyelography (IVP) and renography (RNG) were performed on admittance and 4-5 weeks later, the interval between the IVP and the RNG being 0-4 days. From 80 comparisons of the results of IVP and RNG (prevalence of abnormal IVP 73%), the predictive value of an abnormal RNG in the control situation was found to be 88% with a 95% confidence interval of 75-93%. The predictive value of a normal RNG was 88% (62-98%). If renography was combined with an X-ray of the abdomen at the control examination, the predictive value of an abnormal RNG was unchanged and the predictive value of a normal RNG increased to 100% (77-100%). On the basis of these high predictive values, a new examination protocol for control of patients with unilateral ureterolithiasis is put forward.