Stenosis and renographic characteristics in renovascular disease

This study was designed to determine the degree of renal artery stenosis (RAS) which produces changes in renographic parameters.

The angiographic severity of luminal narrowing in RAS was compared to 131I-hippuran renographic characteristics in 72 patients who have been selected for renal angiography because of suspected renovascular hypertension.

Significant differences in Tmax, T1/2 and counts under the curve to Tmax were apparent at 30% of arterial luminal narrowing when stenotic and nonstenotic kidneys were compared. In patients with unilateral RAS, the difference in counts under the Tmax curve between pairs of kidneys was also significantly different at 30% of stenosis. Patients with bilateral stenosis, on the other hand, could not be differentiated well from patients with essential hypertension because the Tmax value on either side or the difference of Tmax between the two kidneys and the values of the other parameters were similar, except for the difference in counts to Tmax. Based on these findings it seems that bilateral RAS does not "mimic" unilateral stenosis in renographic terms, but rather, resembles a normal situation.

Significant renographic changes can occur at 30% of arterial luminal narrowing in renal artery disease.