title: Glomerular filtration rate measured using the Patlak plot technique and contrast-enhanced dynamic MRI with different amounts of gadolinium-DTPA.
abstract: We determined the optimum gadolinium (Gd)-DTPA dose and time window for calculating the glomerular filtration rate (GFR) using contrast-enhanced (CE) dynamic MRI and the Patlak plot technique. Twelve adult volunteers with healthy kidneys were included in the study. As a reference method the GFR was measured by iopromide plasma clearance. A three-dimensional gradient-echo (GRE) sequence with a flip angle of 50 degrees was used for MRI. Signal was measured using a body surface coil with four elements. Each volunteer was examined on four days using 2 mL, 4 mL, 8 mL, or 16 mL of Gd-DTPA 0.5 mmol/mL dissolved with sodium chloride (NaCl) 0.9% to a total of 60 mL. The injection rate was 1 mL/second. A Patlak plot was calculated from the kidney and aorta signals. The mean reference GFR was 133 mL/min (min-max, 116-153 mL/min). The best correlation of GFR calculated from MRI data compared to the reference method was found in a time window 30-90 seconds after aortic signal rise using 16 mL Gd-DTPA. Pearson's correlation coefficient was r = 0.83, and the standard deviation (SD) from the line of regression was 10.5 mL/minute. We found a significantly lower average GFR(MR) using 16 mL Gd-DTPA compared to 4 mL and 2 mL in the late time window 60-120 seconds post aortic rise. A dose of 16 mL Gd-DTPA was optimal for measuring GFR using dynamic MRI and the Patlak plot technique. The slope should be measured in a time window of 30-90 seconds post aortic rise.
authors.affiliation: Department of Diagnostic Radiology, Justus-Liebig Universität Giessen, Germany. nils.hackstein@radiol.med.uni-giessen.de
authors.forename: Nils
authors.initials: N
authors.lastname: Hackstein
authors.forename: Hendrik
authors.initials: H
authors.lastname: Kooijman
authors.forename: Stefan
authors.initials: S
authors.lastname: Tomaselli
authors.forename: Wigbert S
authors.initials: WS
authors.lastname: Rau
mesh_terms: D000328:Adult; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D005682:Gadolinium / Q000008:administration & dosage*; D005919:Glomerular Filtration Rate / Q000502:physiology*; D006801:Humans; D007267:Injections; D007472:Iohexol / Q000031:analogs & derivatives; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide; D005682:Gadolinium