Contrast Enhanced Magnetic Resonance Angiography (MRA) is a developing technology that permits the non-invasive evaluation of arterial and venous structures without the need for x-ray based catheter angiography. While dramatic progress has been made in the last few years, there are still substantial limitations in the accuracy of MRA in judging stenoses and detecting small accessory vessels. The purpose of this study is to recruit patients with suspected or documented atherosclerotic disease for evaluation with state-of-the-art MRA using new surface coils, new pulse sequence designs, novel contrast administration strategies, and advanced image processing algorithms. This work represents a collaboration between NIH, USUHS and General Electric Medical Systems and is supported by a Cooperative Research Agreement (CRADA). The goal of this pilot study is to improve MRA to the point that it can reliably replace diagnostic x-ray catheter angiography in the evaluation of patients with atherosclerotic disease.