Hypertension in paediatrics: can pre- and post-captopril technetium-99m dimercaptosuccinic acid renal scans exclude renovascular disease?

In children over 1 year of age, renal disease is the commonest cause of hypertension. Arteriography is considered the reference method to establish the diagnosis of renovascular disease; however, it is an invasive technique with a high radiation burden for children. This was a retrospective study of pre- and post-capto-technetium-99m dimercaptosuccinic acid (DMSA) imaging compared with arteriography in 18 children between the ages of 3 and 17 years. Alone, the 99mTc-DMSA scan is a sensitive indicator of renal parenchymal disease, although non-specific in suggesting the pathology. The combination of pre- and post-captopril studies may increase the sensitivity and specificity in the diagnosis of renovascular disease in the presence of hypertension. This work suggests that a screening investigation with a low radiation burden can be carried out at most institutions; if the investigation is positive, there will be a high index of suspicion that renovascular disease is the cause of the hypertension.