Semi-quantitative approach to estimating GFR by magnetic resonance imaging.
OBJECTIVE
The purpose of this study was to compare a semi-quantitative approach to estimating glomerular filtration rate (GFR) by magnetic resonance imaging with radionuclide calculation of GFR, and to investigate whether spin echo or gradient echo is more suitable for estimating GFR.


METHODS
Fourteen kidneys of seven patients (GFR ranging from 26 to 57 ml/min) were studied. Spin echo and gradient echo sequences interleaving each other at every excitation were used. After intravenous injection of gadopentetate dimeglumine, serial scans were performed. The signal intensities measured in the regions of interest were converted to time-transverse relaxation rate changes for both spin echo (DeltaR2) and gradient echo (DeltaR2*). The areas under the time-DeltaR2 and time-DeltaR2* curves were calculated as a semi-quantitative index of GFR for both spin echo and gradient echo images, and the results were compared by GFR measured by radionuclide imaging.


RESULTS
The semi-quantitative index of the GFR calculated from spin echo images showed a significant correlation with the GFR measured by radionuclide imaging (r=0.85, P<0.001). On the other hand, the semi-quantitative index of the GFR calculated from gradient echo images showed no such correlation (r=0.46, P=0.10).


CONCLUSIONS
Spin echo sequences may be more suitable than gradient echo sequences for the evaluation of GFR.
Uematsu
H
H
Department of Radiology, Fukui Medical University, 23 Shimoaizuki, Matsuoka-cho, Yoshida-gun, 910-1193, Fukui, Japan. uematsu@fmsrsa.fukui-med.ac.jp
Matsuda
T
T
Tsuchida
T
T
Inoue
H
H
Hayashi
K
K
Yonekura
Y
Y
Itoh
H
H
D000328:Adult; D000368:Aged; D005260:Female; D019786:Gadolinium DTPA; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging / Q000502:physiology; D007677:Kidney Function Tests / Q000379:methods* / Q000706:statistics & numerical data; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate
D019275:Radiopharmaceuticals; D019786:Gadolinium DTPA; D016284:Technetium Tc 99m Pentetate