DYNAMIC RENAL IMAGING WITH TECHNETIUM-99M-SESTAMIBI IN HYPERTENSION -POTENTIAL FOR ASSESSMENT OF RENOVASCULAR DISORDERS

The myocardial perfusion agent, Tc-99m-sestamibi (MIBI), offers the po tential to combine renal and myocardial imaging because of high initia l renal extraction and significant renal clearance. Methods: Dynamic r enal imaging was performed during rest MIBI injections in 3 normal sub jects (NS) and 91 patients referred for cardiac assessment. Ten served as normal controls, and 81 were hypertensive. Renal activity of MIBI during the first transit, uptake and excretory phases of the study was quantified. These data were compared with the normal kinetics of (TC) -T-99m-diethylenetriaminepentaacetic acid (DTPA) in concurrent studies . Results: With MIBI, clear definition of the kidneys was possible on all phases in most studies; occasionally, overlap with liver or spleen provided a minor problem. Renal MIBI activity reached levels 70% grea ter than DTPA during first transit and remained higher throughout the study; renal/background activity ratios were also higher on the MIBI s tudy (p < 0.001). During the excretory phase with MIBI, hepatic and sp lenic activity did not decline, and gut activity increased. In NS, 40% of the total activity was excreted in the urine in 1 hr; urinary MIBI clearances approximated creatinine clearance. Asymmetry in initial re nal uptake was seen in 14 of 81 hypertensive patients (17%); renal cys ts and aortic dilatation could also be identified. Conclusion: These d ata suggest that ancillary renography during rest injection of MIBI co uld be a useful addition to the cardiovascular assessment of selected patients.