Radionuclide studies of the lower urinary tract.

The results of prospective experimental and clinical studies into the use of radionuclides in the evaluation of urinary flow rates and residual urine volume estimations are presented. The results indicate that the radionuclide estimation of flow rates is accurate, but complex and time-consuming compared with other available methods. The calculation of residual urine is simple and accurate where residual volumes are not extremely large. The opportunity for such lower tract studies after renography should not be missed where clinically appropriate, and the combined upper and lower tract studies provide a useful quantitative urological profile.