This project has two overall objectives: (1) evaluation and refinement of rapid cine phase contrast (Spiral-PC) magnetic resonance imaging (MRI) for accurate, noninvasive measurement of renal blood flow (RBF) in humans; and (2) evaluation of the role of PC-MRI in the diagnosis of renal ischemia due to renal artery stenosis (RAS) that causes renovascular hypertension (RVH), and azotemia due to chronic ischemic nephropathy. Spiral-PC uses spiral K-space trajectories which allow it to be very rapid and have high spatial and temporal resolution. It may be optimal, therefore, for in vivo measurement of RBF since acquisition in a single breathhold interval is necessary. Refinement and optimization of Spiral-PC, and of the measurement of volume flow with analysis software, will be performed initially in phantoms in which flow in renal arteries and veins will be simulated. In vivo validation studies of the accuracy of Spiral- PC for measurement of RBF will be performed in normal subjects who will also have RBF determined by a technique of PAN clearance. Hypertensive and/or azotemic patients with RAS documented arteriographically will have Spiral-PC measurement of RBF, both pre- and post-amino acid infusion (known to raise RBF in normals by 20-30%), MRI-determined renal volumes, and solute clearance studies prior to and following angioplasty or revascularization. The applicants proposed to correlate clitucal response of patients in terms of blood pressure decrease, and increase in GFR with pre-intervention parameters determined by magnetic resonance for each kidney (RBF, RBF/unit renal volume, percent increase in RBF following amino acid infusion), and evaluate the predictive ability of these parameters for patient response to intervention. Yearly follow-up exams in treated patients will include Spiral-PC studies and arteriograms, which will be correlated to determine the potential utility of Spiral PC in detecting restenosis of renal arteries.
| Sommer, Graham; Bouley, Donna; Frisoli, Joan et al. (2007) Determination of 3-dimensional zonal renal volumes using contrast-enhanced computed tomography. J Comput Assist Tomogr 31:209-13 |
| Park, Jong B; Santos, Juan M; Hargreaves, Brian A et al. (2005) Rapid measurement of renal artery blood flow with ungated spiral phase-contrast MRI. J Magn Reson Imaging 21:590-5 |
| Levin, Yakir S; Chow, Lawrence C; Pelc, Norbert J et al. (2005) Estimation of renal extraction fraction based on postcontrast venous and arterial differential T1 values: an error analysis. Magn Reson Med 54:309-16 |
| Chow, Lawrence C; Bammer, Roland; Moseley, Michael E et al. (2003) Single breath-hold diffusion-weighted imaging of the abdomen. J Magn Reson Imaging 18:377-82 |
| Coulam, Curtis H; Bouley, Donna M; Sommer, F Graham (2002) Measurement of renal volumes with contrast-enhanced MRI. J Magn Reson Imaging 15:174-9 |
| Coulam, Curtis H; Lee, Jin H; Wedding, Kristin L et al. (2002) Noninvasive measurement of extraction fraction and single-kidney glomerular filtration rate with MR imaging in swine with surgically created renal arterial stenoses. Radiology 223:76-82 |
| Ramaswamy, Deepa; Corrigan, Geraldine; Polhemus, Catherine et al. (2002) Maintenance and recovery stages of postischemic acute renal failure in humans. Am J Physiol Renal Physiol 282:F271-80 |
| Corrigan, G; Ramaswamy, D; Kwon, O et al. (1999) PAH extraction and estimation of plasma flow in human postischemic acute renal failure. Am J Physiol 277:F312-8 |
| Sommer, G; Corrigan, G; Fredrickson, J et al. (1998) Renal blood flow: measurement in vivo with rapid spiral MR imaging. Radiology 208:729-34 |
| Alley, M T; Pauly, J M; Sommer, F G et al. (1997) Angiographic imaging with 2D RF pulses. Magn Reson Med 37:260-7 |
