Comparison of Different Time-Resolved Methods for Imaging the Vessels of the Lower Extremities

In MRI, commercially-available methods make it possible to acquire contrast-enhanced, time-resolved MR angiograms of vessels throughout the body. This has proven especially useful in imaging the vessels of the lower extremities. However, it is felt that improved temporal resolution would permit better differentiation of arteries and veins, and would offer additional diagnostic information, especially in patients affected by asynchronous flow to contralateral limbs; and improved spatial resolution would allow for better delineation of pathology. In recent years, UW-Madison and other institutions have developed 3D time-resolved methods that offer improved temporal and spatial resolution compared to the commercially-available 3D time-resolved methods. Characterizing the attributes of these methods in a systematic study is necessary in order to determine which method will succeed the currently-available commercial methods. The goal of this study is to perform a systematic evaluation to compare the performance of 5 three-dimensional, time-resolved methods for imaging the vessels of the lower extremities. Three of the methods have been developed by UW (VIPR, HYPR VIPR, and IVD HYCR) and two of the methods have been developed by other institutions (a CAPR-like method and a DISCO-like method). In this study, we will image healthy volunteers as well as patients with peripheral vascular disease. Metrics of image quality will be assessed such as signal-to-noise ratio, spatial resolution, temporal resolution, artery-vein separation, temporal fidelity, artifact level, diagnostic accuracy, as well as other factors.