DEVELOPMENT OF SURFACE COILS FOR MAGNETIC RESONANCE IMAGING

THE SPECIFIC AIM OF THIS PROPOSAL IS TO DEVELOP A FAMILY OF SURFACE COILS FOR MAGNETIC RESONANCE IMAGING (MRI). WHEN SURFACE COILS ARE UTILIZED, MRI IMAGES SHOW IMPROVED SPATIAL RESOLUTION AND SIGNAL-TO-NOISE RATIOS. HIGH-RESOLUTION IMAGING OF THE CENTRAL NERVOUS SYSTEM, EXTREMITIES, AND PERHAPS THE CORONARY ARTERIES WILL BE POSSIBLE WITH IMPROVED SURFACE COIL DESIGN. THIS WOULD LEADTO IMPROVED DIAGNOSIS OF CANCERS, TRAUMA, AND OTHER DISEASES. TO DETECT THE SMALL RADIO-FREQUENCY SIGNALS USED TO FORM THEMRI IMAGE, SURFACE COIL DESIGNS WILL: (1) MAXIMIZE THE ORGAN-FILLING FACTOR, (2) MAXIMIZE RECEIVER HOMOGENEITY, (3)MAXIMIZE QUALITY FACTOR Q, AND (4) MINIMIZE PATIENT DIELECTRIC COUPLING. TO REALIZE THESE FACTORS, PARALLEL AND SERIES-PARALLEL CIRCUIT DESIGNS WILL MAXIMIZE Q BY MINIMIZING INTERNAL AND EXTERNAL LOSSES THROUGH DISTRIBUTED CAPACITANCES. MATERIAL RESEARCH WILL BE CARRIED OUT TO IDENTIFT LOW-RESISTIVITY, LOW-DISSIPATION FACTOR COMPONENTS AND COIL MATERIALS. COIL GEOMETRIES WILL BE COMPUTER MODELED TO MAXIMIZE THE FILLING FACTOR AND REDUCE EXTERNAL COUPLING. JUDICIOUS CHOICE OF CIRCUIT/COIL DESIGNS AND MATERIALS WILL MAXMIMIZE Q, WHILE MATCHING COIL IMPEDANCE TOMRI UNIT REQUIREMENTS FOR HIGH SIGNAL-TO-NOISE IMAGING. BENCH TESTING AND MRI IMAGER EVALUATION WILL ASSESS THE COIL-LOADED Q, SIGNAL-TO-NOISE RATIO, AND IMPEDANCE MATCHING TO PRODUCE HIGH-QUALITY MRI IMAGES.