Patients at high risk for renal artery stenosis: a simple method of renal scintigraphic analysis with Tc-99m DTPA and captopril.
Fifty patients with suspected renal artery stenosis (RAS) were studied with renal scintigraphy before and after administration of captopril. Twenty-three patients had RAS (greater than or equal to 75% RAS or greater than or equal to 50% RAS with poststenotic dilatation) and 27 had normal renal arteries at angiography. Angiotensin-converting enzyme inhibitors were discontinued 24 hours prior to renal scintigraphy; all other medications were continued. Each patient was evaluated with a simplified captopril renal scintigraphic protocol: renal imaging after administration of 12 mCi (444 MBq) of technetium-99m diethylenetriaminepentaacetic acid (DTPA), a 3-hour wait, oral administration of 50 mg of captopril, a 1-hour wait, and another scintigram obtained after administration of 12 mCi (444 MBq) of Tc-99m DTPA. Times of peak renal activity (Tmax) were determined from renal time-activity curves, and glomerular filtration rates (GFRs) were calculated with the Gates technique. A Tmax greater than or equal to 11 minutes after injection or a GFR ratio (larger GFR/smaller GFR) greater than 1.5 enabled detection of RAS with 91% sensitivity, 93% specificity, and 92% accuracy. Renal scintigraphy without captopril had only 43%-68% sensitivity in detecting RAS, depending on the criteria used.
Chen
C C
CC
Department of Diagnostic Imaging, Yale University School of Medicine, New Haven, CT 06510.
Hoffer
P B
PB
Vahjen
G
G
Gottschalk
A
A
Koster
K
K
Zubal
I G
IG
Setaro
J F
JF
Roer
D A
DA
Black
H R
HR
D002216:Captopril / Q000008:administration & dosage* / Q000494:pharmacology; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology; D007668:Kidney / Q000187:drug effects; D008722:Methods; D015609:Organotechnetium Compounds; D004369:Pentetic Acid; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D012078:Renal Artery Obstruction / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016284:Technetium Tc 99m Pentetate
D015609:Organotechnetium Compounds; D004369:Pentetic Acid; D002216:Captopril; D016284:Technetium Tc 99m Pentetate