[Captopril-enhanced renography using 99mTc-DTPA in renovascular hypertensive patients].
Dynamic renal scintigraphy with 99mTc-DTPA before (baseline renography: BS-RG) and 1 hour after administration of 25 mg to 50 mg of captopril (captopril-enhanced renography: CP-RG) was performed in a selected series of 18 patients suspected of having renovascular hypertension. Final diagnosis was made by angiography and further clinical follow-up. Eight patients were considered as renovascular hypertension (RVH), 6 with bilateral renal artery stenosis (BRAS) and 2 with unilateral renal artery stenosis (URAS). The remaining 10 patients were non-renovascular (non-RVH). Two criteria were prospectively employed for evaluating positive response induced by captopril. Glomerular filtration rate (GFR) on BS-RG (GFRbase) and on CP-RG (GFRcap) was estimated by early (120-180 seconds) DTPA uptake by the kidney, and then captopril response rate (CRR) was calculated in the following: CRR = (GFRcap-GFRbase)/GFRbase X 100 (%). CP-RG was considered positive when it was less than 20%. Renogram shape was also independently evaluated. CP-RG was also considered positive when either a delay of time to peak activity of more than 5 min or conversion of renogram shape to an obstructive or non-functioning pattern was observed. The sensitivity and specificity of CRR and change in renogram were 50% and 80%, 63% and 100%, respectively. In BRAS, positive response was observed in the unilateral kidney alone which maintained relatively a good renal function. CP-RG could not differentiate RVH with URAS from that with BRAS. Four patients were followed after the surgical or angioplastic treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Nuclear Medicine, Hokkaido University School of Medicine.
K
K
Itoh
H
H
Kakizaki
C
C
Kato
E
E
Tsukamoto
K
K
Nakada
K
K
Nagao
M
M
Togashi
M
M
Furudate
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002216:Captopril; D002648:Child; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006801:Humans; D006978:Hypertension, Renovascular / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D004369:Pentetic Acid; D011446:Prospective Studies; D011866:Radioisotope Renography / Q000379:methods; D016284:Technetium Tc 99m Pentetate
D015609:Organotechnetium Compounds; D004369:Pentetic Acid; D002216:Captopril; D016284:Technetium Tc 99m Pentetate