Chronic kidney disease (CKD) is a global problem affecting 500 million people worldwide. Glomerular filtration rate (GFR) is the clinical standard assay for the assessment of kidney function, however existing estimation techniques are imperfect. Gold-standard, accurate, collection based GFR techniques are time consuming, complex and rarely used, whereas cheap, effective GFR test like serum creatinine are often inaccurate. As a result, CKD, particularly subclinical CKD (Stage 1 and 2, GFR 60-100 ml/min) is grossly under-diagnosed and vastly understudied. Accurate identification of CKD is particularly important in Black Americans. Despite recent improvements in outcomes, CKD remains 15% more common, and end stage renal disease 3x more common in Black Americans as compared to non-Black Americans. Medical policy, genetics, economics and social factors have all been suggested as casual reasons for the observed inequities in renal outcomes. Unfortunately, until better screening tools of early renal disease are available, the exact determinants of CKD will be difficult to establish. Toward this end, we hypothesize that overcoming technical challenges related to motion sensitivity and physiological MR modeling will enable renal functional magnetic resonance imaging (rfMRI) to generate biomarkers that have superior safety, ease and accuracy as compared to existing GFR techniques The proposed aims will develop, validate and test two novel methods of GFR determination in Black Americans with a propensity for subclinical kidney disease. Aim 1: Develop and Validate Robust Oximetry and DeoxyHb Dynamic Susceptibly Contrast (dDSC) MRI. Aim 2: Develop and Validate Motion Robust, Blood Water, PROPELLER Renal Arterial Spin Labeling MRI. Aim 3: Evaluate Non-Contrast rfMRI in Adult African Americans with Subclinical Renal Disease. This proposal will consist of critical development and evaluation steps that will help characterize and facilitate the rapid and widespread adoption of non-ionizing, non-contrast hydro/hemodynamic biomarkers of renal function for a historically underserved population and all patients with kidney disease.

Glomerular filtration rate (GFR) is the clinical standard assay for the assessment of kidney function, however existing estimation techniques are imperfect. The goal of this work is to therefore develop, validate and evaluate novel, non-ionizing, non-contrast renal functional MRI markers of blood flow, blood oxygen and GFR using advanced modeling, data acquisitions and image reconstruction approaches. We will evaluate our techniques in a large population of African Americans as a first step towards demonstrating efficacy in all patients with kidney disease.