In recent years, we have developed new intravascular MRI (IVMRI) probes in the form of guidewires and catheters for use in animal models. We have also developed IVMRI techniques that enable acquisition of high resolution cross-sectional images of the vessel wall, as well as tracking techniques for real-time visualization of the catheters. We believe that using these techniques, valuable information can be obtained for the diagnosis and treatment of atherosclerosis of other vessel diseases in humans. In this proposal, we will test the hypotheses that our IVMRI technique () is a low-risk method and (b) can be used for the visualization of interventional techniques, namely balloon angioplasty and stent placement procedures. Specifically, we will (1) refine and adapt our existing IVMRI probes in the form of catheters and guidewires that will be suitable for use in human patients, and (2) evaluate the safety of these devices in accord with FDA-established guidelines by calculating/measuring the additional heating caused by the presence of the intravascular MRI devices and assessing any potential for tissue damage. We will also (3) evaluate whether currently available perfusion MR imaging and non-invasive MR angiography (MR) techniques can be combined with IVMRI techniques to perform intravascular MR fluoroscopy (IVMRF)-guided interventional procedures, namely, balloon angioplasty and stent placement in animal models. In the final phase of the project, we plan to have enough data to apply for IRB approval for investigational use of these techniques in human patients.