title: Radioisotopic measurement of glomerular filtration rate in severe chronic renal failure.
abstract: In order to determine the best method for routine measurement of glomerular filtration rate (GFR) in severe renal failure, we compared simultaneously the urinary clearances of [99mTc] diethylenetriaminepentaacetic acid (DTPA) (UD), [125I]iothalamate (UI), 24-hr creatinine clearance (UC) and plasma clearance of [99mTc]DTPA (PD), based on three plasma samples. In 60 studies in 22 patients with serum creatinine values of 2 to 8 mg/dl, UD and UI were almost identical: UD = 0.358 +/- 0.976 UI +/- 0.87 ml/min, r = 0.990. However, PD overestimated UD by a large and variable extent: PD = 11.3 +/- 0.843 UD +/- 5.5 ml/min, r = 0.694, and was inconsistent in sequential measurements in individual patients. UC also overestimated urinary isotope clearance: UC = 4.2 + 0.95 UI +/- 3.9 ml/min, r = 0.865. Sequential measurements of GFR in five patients with severe but stable renal failure (mean GFR 5.9 ml/min) showed an average standard deviation of only 0.83 ml/min. Thus both UD and UI appear to be reliable and precise measures of GFR in severe renal failure.
authors.affiliation: Department of Radiology, Johns Hopkins University, School of Medicine, Baltimore, Maryland.
authors.forename: N D
authors.initials: ND
authors.lastname: LaFrance
authors.forename: H H
authors.initials: HH
authors.lastname: Drew
authors.forename: M
authors.initials: M
authors.lastname: Walser
mesh_terms: D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007457:Iodine Radioisotopes; D007483:Iothalamic Acid; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D009942:Organometallic Compounds; D004369:Pentetic Acid; D011866:Radioisotope Renography; D016284:Technetium Tc 99m Pentetate
chemical_list: D007457:Iodine Radioisotopes; D009942:Organometallic Compounds; D007483:Iothalamic Acid; D004369:Pentetic Acid; D016284:Technetium Tc 99m Pentetate