DIURETIC RENAL SCAN - IS IT ALWAYS RELIABLE

The differentiation between significant mechanical obstruction and non obstructive dilation of the kidneys and ureters is fundamental to pati ent management. The diuretic renal scan is a useful test in this situa tion because it usually is reliable and reproducible and is noninvasiv e and objective, providing information about the function of each kidn ey. However, this study has given variable results in a small number o f patients. We report our experience with five such patients and recom mend an algorithm for evaluating patients with equivocal scan results. This report emphasizes the importance of continued follow-up and the need for periodic reevaluation of patients with unexplained urinary sy mptoms or persistent flank pain, even when the initial diuretic renal scan is normal.