GENERATION OF MAGNETIC RESONANCE IMAGES OF INTRACRANIAL AND EXTRACRANIAL CAROTID ARTERIAL LUMENS, TOGETHER WITH RELATED VOLUME BLOOD FLOW INFORMATION FOR EACH LUMEN, HAS POTENTIAL FOR PROVIDING A NONINVASIVE AND MORE DEFINITIVE TECHNIQUE FOR DIAGNOSIS OF

GENERATION OF MAGNETIC RESONANCE IMAGES OF INTRACRANIAL AND EXTRACRANIAL CAROTID ARTERIAL LUMENS, TOGETHER WITH RELATED VOLUME BLOOD FLOW INFORMATION FOR EACH LUMEN, HAS POTENTIAL FOR PROVIDING A NONINVASIVE AND MORE DEFINITIVE TECHNIQUE FOR DIAGNOSIS OF INCIPIENT STROKE DUE TO ARTERIAL DISEASE THAN EITHER ULTRASOUND OR ANGIOGRAPHY. TO DEMONSTRATE THIS POTENTIAL, WE PROPOSE TO APPLY A SENSITIVE LINE/FAST PASSAGE SCANNING METHOD, WHICH IS SPECIFICALLY SUITED TO IMAGING AND QUANTIFYING BLOOD IN MOTION RATHER THAN TISSUE AT REST. A CYLINDRICAL RESONANT VOXEL COAXIAL WITH THE LUMEN IS DEFINED BY 2 ROTATING GRADIENT FIELDS AND A FAST PASSAGE ABSORPTION NOTCH. THE PULSATILE, REAL-TIME NMR SIGNAL IS PROPORTIONAL TO BLOOD VOLUME FLOW RATE PER VOXEL AREA AND IS ALREADY IN THE FREQUENCY DOMAIN. THE DATA ARE COMPUTER PROCESSED TO PROVIDE A VIDEO PRESENTATION OF LUMEN SHAPE, A 2-D COLOR-CODED VELOCITY PROFILE, THE PULSE WAVE FORM, AND AVERAGE AND PEAK SYSTOLIC VOLUME FLOW RATES. IN PHASE I, WE PROPOSE TO DEMONSTRATE THE FEASIBILITY OF CAROTID ARTERIAL MEASUREMENTS BY OUR METHOD USING A .15T PERMANENT MAGNET AT THE MEDICAL COLLEGE OF WISCONSIN. GUIDED BY THESE RESULTS, PHASE II WILL BE R&D LEADING TO A UNIT USING A 0.3T PERMANENT MAGNET.