Captopril-enhanced 99mTc DTPA scintigraphy in the detection of renal-artery stenosis.

The value of captopril-enhanced 99mTc DTPA scintigraphy as a screening test for renovascular disease was prospectively studied in 44 hypertensive patients suspected to have renal-artery stenosis. Renal impairment (plasma creatinine greater than 130 mumol/l) was present in 29 patients. At angiography 13 patients had unilateral stenosis, two bilateral stenosis, and 29 patients had no renovascular disease. Captopril induced a fall in split renal function in the kidney ipsilateral to the stenosis in all patients with unilateral disease (mean 52 +/- 23% to 44 +/- 21% of total renal function; P less than 0.001). A positive captopril scintigram (defined as a fall of 5% or more in split renal function) had a sensitivity of 85% and a specificity of 72% in the detection of unilateral renal-artery stenosis. Captopril-enhanced 99mTc DTPA scintigraphy is a promising non-invasive screening test for the detection of renal-artery stenosis.