TC-99M-MAG3 RENAL-FUNCTION SCINTIGRAPHY AND CAPTOPRIL IN THE DIAGNOSIS OF RENOVASCULAR HYPERTENSION

In this study, the diagnostic value of renal function scintigraphy performed both without and with ACE inhibition has been evaluated using the new radio-pharmaceutical Tc-99m-MAG3. In cases of decompensated renal artery stenoses, the typical scan finding with this tubular excreted agent was shown to be a distinct parenchymal nuclide retention in combination with a delayed appearance of the radiotracer in the pelvic system. Using this criterion in 43 patients with suspected renovascular hypertension, sensitivity and specificity were 89 and 88 %, respectively. Bilateral positive findings were non-specific; excluding them from the study, specificity increased to 100 %. In renal insufficiency, captopril scans seem to be of reduced diagnostic value. Summarising our experiences, renal function scintigraphy using Tc-99m-MAG3 without and with captopril was proved to be a reliable non-invasive method to detect or exclude haemodynamically relevant renal artery stenosis.