Individual kidney blood flow measured with contrast-enhanced first-pass perfusion MR imaging

The study design was HIPAA-compliant and approved by the Institutional Review Board, with all participants providing signed informed consent prior to the study. The purpose of this study was to prospectively evaluate the feasibility of determining renal blood flow (RBF) by using a technique based on intravenous administration of gadolinium chelate and evaluation of first-pass gadolinium chelate perfusion by using highly accelerated three-dimensional (3D) gradient-echo magnetic resonance (MR) imaging of the kidney in freely breathing subjects. Flow is determined with Kety-Schmidt formalism by modeling the uptake of gadolinium chelate in the kidney prior to its leaving through the venous system. Validation of the gadolinium chelate perfusion technique is based on comparison of values determined for participants with phase-contrast gradient-echo imaging. The model fit to the measured data is excellent over the first 7-8 seconds of gadolinium chelate uptake and diverges after its appearance in the renal vein. The perfusion data analysis technique showed less than 10% interobserver variation. The average difference between phase-contrast and gadolinium chelate perfusion measurements was 0.08 mL/sec (95% confidence interval: -3.73, 3.58) for left and right kidneys. This study demonstrates feasibility of the gadolinium chelate perfusion method for RBF measurement and discusses potential applications. (c) RSNA, 2008.