The diagnostic dilemma: a clinician's viewpoint

The prevalence of renovascular hypertension appears to be increasing, particularly in older patients with generalized arteriosclerosis, hypertension and impaired renal function. While clinical clues remain extremely useful in identifying patients at increased risk, older screening tests have been largely abandoned in favor of angiographic methods that provide visual identification of renal artery lesions. Renal scintigraphic techniques, with or without angiotensin-converting enzyme (ACE) inhibition, offer the potential for providing accurate measurements of renal function, and may be particularly useful in identifying critical renal arterial stenosis. In assessing the future role of scintigraphy, careful clinical validation of these correlations will be necessary, as will determinations of their usefulness in patients with renal insufficiency and those with bilateral renal artery stenosis. The role of adrenal scintigraphy in the localization of adrenal tumors is also reviewed. Their cost-effectiveness, limitations in sensitivity and specificity compared to current diagnostic technologies, and potential applications are discussed.