Measurement of single-kidney glomerular filtration rate using a contrast-enhanced dynamic gradient-echo sequence and the Rutland-Patlak plot technique
✍ Scribed by Nils Hackstein; Jan Heckrodt; Wigbert S. Rau
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 277 KB
- Volume
- 18
- Category
- Article
- ISSN
- 1053-1807
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✦ Synopsis
Purpose:
To determine the accuracy of single-kidney glomerular filtration rate (gfr) determination using contrast-enhanced dynamic magnetic resonance imaging (mri) and the rutland-patlak plot technique.
Materials and methods:
Twenty-eight adult patients were included. as reference method, the gfr was measured by plasma clearance using a small bolus injection of iopromide. a three-dimensional gradient-echo (gre) sequence with a flip angle of 50 degrees was used for mri; this showed a good linear relationship between gadolinium (gd)-dtpa concentration and signal change when measured up to a gd-dtpa concentration of 10 mmol/liter. a slab containing both kidneys and the abdominal aorta was measured 30 times in approximately 3.5 minutes. during this measurement, 15 ml of gd-dtpa, 0.5 mol/liter diluted to a volume of 60 ml, was injected over 60 seconds. a rutland-patlak plot was calculated from the signal changes in the aorta and the renal parenchyma. single-kidney gfr was calculated for different time windows from the rutland-patlak plot slope.
Results:
The best correlation compared to the reference method was found with the gfr calculated from the slope of the rutland-patlak plot 40-110 seconds postaortic rise. pearson's correlation coefficient was r = 0.86, sd was 14.8 ml/minute. in many of the patients, a decrease of the renal signal was observed in the excretory phase, which was probably caused by very high gd-dtpa concentrations in the collecting tubules.
Conclusion:
Single-kidney gfr can be calculated from dynamic contrast-enhanced mri. we found a promising correlation of global gfr calculated by mri compared to the reference method. in any future study, the amount of gd-dtpa should by reduced to avoid artificial signal drop in the excretory phase induced by the t2* effect.