MRI Technical Development and Applications in Kidney Disease

Specific Aims The overall objective is to develop and validate MRI methods for the evaluation and monitoring of renal status and associated cerebrovascular effects of renal dysfunction and treatment. The proposed project include two phases: 1) MRI technical development and validation with reproducibility studies; 2) clinical pilot studies with two patient populations (CKD patients and renal transplant recipients) to explore the potential of MRI in evaluating CKD, post-transplantation renal dysfunction and cerebrovascular pathophysiology associated with or induced by reduced kidney function and renal replacement treatment. The ultimate goal is to use MRI as a non-invasive and non-contrast enhanced tool to facilitate the diagnosis and prognosis of renal dysfunction and associated diseases, and to assess the efficacy of therapeutic interventions, and monitor disease progress across time. Specific Aim 1: Imaging technical development and protocol optimization for renal and cerebral MRI. The overall goal is to develop, customize and optimize new MRI methods to overcome challenges due to physiological motions and facilitate clinical research studies of renal and cerebral diseases, which will include but not are limited to the following aspects. Sub-Aim 1.1: Develop imaging methods to improve MRI quality and efficiency for renal disease studies. Sub-Aim 1.2: Optimize gas-challenge functional MRI protocols to study cerebral and renal vascular endothelial dysfunction. Sub-Aim 1.3: Evaluate the reproducibility of cerebral and renal MRI methods. Specific Aim 2: Perform pilot studies to evaluate the potential of MRI in CKD patients and renal transplant recipients. Sub-Aim 2.1: Evaluate the correspondence of MRI measures with clinical metrics (i.e. eGFR) and routinely assessed cognitive functions from CKD and ESRD patients. This will be accomplished by performing both cross-sectional and longitudinal studies, which will allow us to evaluate the diagnostic and prognostic potential of these non-invasive imaging methods. The investigators hypothesize that the measurements from cerebral and/or renal MRI can effectively reflect cerebral and/or renal (anatomic and physiological) changes induced by CKD or dialysis treatment. Sub-Aim 2.2: Investigate the potential of MRI methods in the evaluation of post-transplant kidneys. This will be accomplished by imaging transplant recipients in three distinct cohorts; those with good allograft function but coming in for routine protocol biopsy, with stable renal function, and with unstable renal function due to post-transplant complications. These patient populations will receive protocol biopsies (i.e. scheduled repeat biopsies) as standard of care; therefore pathologic results will be available for correlation with MRI measures. The investigators hypothesize that MRI methods can be a non-invasive surrogate marker of renal tissue properties and functional changes induced by renal post-transplant dysfunction (e.g. renal rejection) currently only obtained through biopsy.