Renovascular hypertension may be suggested by finding a renal artery bruit. This is best heard over the long muscles of the back at the level of Ll or in the epigastrium. In many patients, however, there are no clinical clues. Isotope renography may reveal decreased uptake, and delayed excretion, of the isotope on the side of the lesion. Although this technique is less expensive than intravenous urography, it is also less widely available. On urography, a delayed nephrogram may be seen on the stenotic side in early films, with increased density and delayed excretion in later films (Fig. 10.11).
