title: A simple method for measuring severely reduced glomerular filtration rate.
abstract: OBJECTIVE
  The purpose of this study was to develop a simpler method to measure severely reduced glomerular filtration rate (GFR) for patients with a GFR below 30 mL/min.
  
  
  METHODS
  The GFR was measured in 24 patients using both the 51Cr EDTA slope-intercept method (the conventional method) and 99mTc-DTPA with our proposed simpler GFRn method.
  
  
  RESULTS
  The correlation coefficient was 0.92 between the 2 methods, with a slope of 0.97 and an intercept of 2 mL/min.
  
  
  CONCLUSIONS
  Our simplified method for measuring GFR is accurate for most patients with severely reduced GFR. Errors are acceptably small in patients with severely reduced GFR when edema or dehydration are present. If extrarenal (liver) clearance is significant, however, a urine sampling method is required for an accurate GFR measurement.
authors.affiliation: Department of Nuclear Medicine, Medical University of Southern Africa, Medunsa. ajwhite@medunsa.ac.za
authors.forename: A J
authors.initials: AJ
authors.lastname: White
authors.forename: M
authors.initials: M
authors.lastname: Rachalewska
authors.forename: R R
authors.initials: RR
authors.lastname: Venkannagari
mesh_terms: D000465:Algorithms; D001830:Body Surface Area; D002614:Chelating Agents; D002860:Chromium Radioisotopes / Q000652:urine; D003681:Dehydration / Q000503:physiopathology; D004487:Edema / Q000503:physiopathology; D004492:Edetic Acid; D005110:Extracellular Space / Q000378:metabolism; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000378:metabolism / Q000503:physiopathology; D016014:Linear Models; D008099:Liver / Q000378:metabolism; D011866:Radioisotope Renography; D019275:Radiopharmaceuticals / Q000652:urine; D016284:Technetium Tc 99m Pentetate / Q000652:urine
chemical_list: D002614:Chelating Agents; D002860:Chromium Radioisotopes; D019275:Radiopharmaceuticals; D004492:Edetic Acid; D016284:Technetium Tc 99m Pentetate