Glomerular filtration rate estimated from the uptake phase of 99mTc-DTPA renography in chronic renal failure.
BACKGROUND
The purpose of the study was to compare the estimation of glomerular filtration rate (GFR) from 99mTc-DTPA renography with that estimated from the renal clearance of 51Cr-EDTA, creatinine and urea.


METHODS
Fifty patients with reduced renal function (serum creatinine between 150 and 600 micromol/l) were enrolled in the study. GFR was estimated from the uptake phase of 99mTc-DTPA renography (GFR(DTPA)). The renal clearance of 51Cr-EDTA (GFR(EDTA)) was used as the reference method. Creatinine clearance (C(Cr)), urea clearance (C(Ur)) and the mean of urea and creatinine clearance (C(Cr+Ur)/2) were also calculated from urine collected during a period of 24 h. Limits of agreement were used for method comparison.


RESULTS
The limit of agreement between GFR(DTPA) and GFR(EDTA) was 2 +/- 17 ml/min. The mean difference did not deviate significantly from zero. The other clearance techniques had larger limits of agreement and a mean difference significantly different from zero. Furthermore, C(Ur) and C(Cr+Ur)/2 had systematic deviations of the differences, indicating that C(Ur) and C(Cr+Ur)/2 are poor estimates of GFR.


CONCLUSIONS
The limit of agreement between GFR(DTPA) and GFR(EDTA) are acceptable and, therefore, GFR estimated from 99mTc-DTPA renography is acceptable for clinical use in patients with reduced renal function. Furthermore, the method is simple and less time consuming compared with renal clearance techniques.
Petersen
L J
LJ
Department of Nephrology, Hvidovre Hospital, Denmark.
Petersen
J R
JR
Talleruphuus
U
U
Møller
M L
ML
Ladefoged
S D
SD
Mehlsen
J
J
Jensen
H A
HA
D000328:Adult; D000368:Aged; D003404:Creatinine / Q000378:metabolism; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D016284:Technetium Tc 99m Pentetate / Q000493:pharmacokinetics*; D014508:Urea / Q000378:metabolism
D019275:Radiopharmaceuticals; D014508:Urea; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate