Measurement of single kidney function using dynamic contrast-enhanced MRI: Comparison of two models in human subjects

Purpose To compare two methods for assessing the single kidney glomerular filtration rate (SK‐GFR) in humans using dynamic contrast‐enhanced (DCE)‐MRI. Materials and Methods Images were acquired from 39 separate MR studies of patients with atherosclerotic renovascular disease (ARVD). Data from the kidneys and descending aorta were analyzed using both a Rutland‐Patlak plot and a compartmental model. MR estimates of the SK‐GFR were compared with standard radioisotope measures in a total of 75 kidneys. Results Estimates of renal function using both techniques correlated well with radioisotope‐assessed SK‐GFR (Spearman's ρ = 0.81, Rutland‐Patlak; ρ = 0.71, compartmental model). The Rutland‐Patlak approach provided a near one‐to‐one correspondence, while the compartmental method tended to overestimate SK‐GFR. However, the compartmental model fits to the experimental data were significantly better than those obtained using the Rutland‐Patlak approach. Conclusion DCE‐MRI of the kidneys provides data that correlate well with reference measures of SK‐GFR. However, further work, including image registration, is needed to isolate measurement of glomerular filtration to the level of the renal cortex. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.