DIAGNOSTIC-CRITERIA IN TC-99M-MAG(3) RENA L-FUNCTION SCINTIGRAPHY WITH CAPTOPRIL

Renal function scintigraphy under ACE inhibition has gained an importa nt role in the diagnosis of renovascular hypertension. Using the radio pharmaceutical Tc-99m-MAG(3), 54 kidneys with angiographically verifie d renal artery status were evaluated with respect to the following sci ntigraphic parameters: intraparenchymal tracer transport, urine draina ge, kidney size, and functional side-to-side ratio. In cases of decomp ensated renal artery stenosis, the typical scan finding using MAG(3) w as shown to be a distinct parenchymal nuclide retention in combination with a delayed appearance of the radiotracer in the pelvic system. In our patients, the visual impression of the renal sequential scans was superior to quantitative evaluation methods. Using these criteria in 43 patients with suspected renovascular hypertension, sensitivity and specificity were 89% and 88%, respectively. Bilateral positive finding s were non-specific; when excluding them from the study, specificity i ncreased to 100%.