Dynamic contrast-enhanced MRI measurement of renal function in healthy participants

Background: High repeatability, accuracy, and precision for renal function measurements need to be achieved to establish renal dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) as a clinically useful diagnostic tool. Purpose: To investigate the repeatability, accuracy, and precision of DCE-MRI measured renal perfusion and glomerular filtration rate (GFR) using iohexol-GFR as the reference method. Material and Methods: Twenty healthy non-smoking volunteers underwent repeated DCE-MRI and an iohexol-GFR within a period of 10 days. Single-kidney (SK) MRI measurements of perfusion (blood flow, Fb) and filtration (GFR) were derived from parenchymal intensity time curves fitted to a two-compartment filtration model. The repeatability of the SK-MRI measurements was assessed using coefficient of variation (CV). Using iohexol-GFR as reference method, the accuracy of total MR-GFR was determined by mean difference (MD) and precision by limits of agreement (LoA). Results: SK-Fb (MR1, 345 +/- 84; MR2, 371 +/- 103 mL/100 mL/min) and SK-GFR (MR1, 52 +/- 14; MR2, 54 +/- 10 mL/min/ 1.73m(2)) measurements achieved a repeatability (CV) in the range of 15-22%. With reference to iohexol-GFR, MR-GFR was determined with a low mean difference but high LoA (MR1, MD 1.5 mL/min/1.73m(2), LoA [-42, 45]; MR2, MD 6.1 mL/min/1.73m(2), LoA [-26, 38]). Eighty percent and 90% of MR-GFR measurements were determined within +/- 30% of the iohexol-GFR for MR1 and MR2, respectively. Conclusion: Good repeatability of SK-MRI measurements and good agreement between MR-GFR and iohexol-GFR provide a high clinical potential of DCE-MRI for renal function assessment. A moderate precision in MR-derived estimates indicates that the method cannot yet be used in clinical routine.