The overall goal of this research is the development of a diagnostic methodology for predicting whether treatment of atherosclerotic stenoses in the renal artery will provide sufficient benefit in controlling hypertension or maintaining renal function to offset the risks of the treatment. Stenoses in the renal artery are comparatively common, yet prior studies have shown that 20 to 40% of patients show little or no benefit from angioplasty or stenting. Since the treatment carries significant risk, the ability to identify patients who will not benefit from treatment (and, conversely, to indicate those patients who will be most likely to have positive outcomes) is an important need in management of renovascular disease. The objective of the research is to develop and evaluate methodologies for noninvasive evaluation of the hemodynamic significance of the stenosis, which prior work indicates is directly related to the outcome of treatment. Two alternative model-based approaches for this evaluation will be developed in the proposed project. A pulsatile flow phantom will be constructed and tested to provide anatomic and flow/pressure data for model development and assessment. ? ? ?