[Evaluation criteria for captopril-kidney function scintigraphy using 99mTc-MAG3].

Renal function scintigraphy under ACE inhibition has gained an important role in the diagnosis of renovascular hypertension. Using the radiopharmaceutical 99mTc-MAG3, 54 kidneys with angiographically verified renal artery status were evaluated with respect to the following scintigraphic parameters: intraparenchymal tracer transport, urine drainage, kidney size, and functional side-to-side ratio. In cases of decompensated renal artery stenosis, the typical scan finding using MAG3 was 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 findings were nonspecific; when excluding them from the study, specificity increased to 100%.