The proposal outlines the investigation of the magnetic resonance (MR) examination parameters that can be used to rapidly provide high quality angiographic images and quantitative flow data of intra- and extra-cranial blood vessels in conjunction with conventional brain imaging. These imaging techniques will then be tested in a clinical setting to verify more physiologic accuracy using intraarterial angiography and doppler ultrasound as objective measures of accuracy. The experiments will address time-of-flight MR angiography with respect to: 1) Optimization of vessel signal and contrast by pulse sequence design to maximize flow related enhancement (orientation, repetition time (TR), flip angle) and minimize motion induced phase dispersion (voxel size, refoccusing techniques and echo-time (TE) reduction). 2) Improvements in spatial resolution in the presence of data sampling and field of view constraints via new reconstruction techniques and optimized sequences. 3) Artifact reduction and isolation of vascular territories by implementing saturation pulses. 4) Physiological monitoring/flow quantification via phase analysis utilizing Doppler ultrasound as a measure of accuracy in patients. 5) Verification of morphologic accuracy and anatomic fidelity using conventional intraarterial angiography as a standard of comparison for both individual 2D and 3D projections. 6) Clinical trials in circumstances of cerebrovascular disease not readily amenable to presently available diagnostic techniques. While parenchymal MR changes are commonly used in clinical practice, application of flow effects remain limited. Research in this area will provide a better, practical understanding of MR's potential as a routine vascular imaging modality. The ultimate goal is the development of a reliable, cost-effective and non-invasive clinical exam providing accurate vascular images and flow data in conjunction with routine MR with minimal or no increase in patient exam time (and thus expense).
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