Concentric dual-loop RF coil for magnetic resonance imaging ∗

SE DESARROLLO UNA ANTENA SUPERFICIAL PARA SER USADA EN IMAGENOLOGIA UN SISTEMA RM COMERCIAL. PREVIO A LA CONSTRUCCION DEL PROTOTIPO, SIMULAMOS EL CAMPO MAGNETICO GENERADO POR LA ANTENA. LA SIMULACION DEL CAMPO ESTUVO BASADA EN LA LEY DE BIOT-SAVART PARA LOS CASOS DE LA ANTENAS DE UNA SOLA ESPIRA DE FORMA CUADRADA Y CIRCULAR. DE ESTOS RESULTADOS SE PUEDE APRECIAR UNA MEJORA EN LA HOMOGENEIDAD DEL CAMPO. SE COMPARARON LOS COCIENTES DE SENAL A RUIDO (S/R) EXPERIMENTALES DE UNA ANTENA SUPERFICIAL DE UNA SOLA ESPIRA Y LA ANTENA CONCENTRICA DE DOS ESPIRAS CON GEOMETRIAS DISTINTAS. LAS GRAFICAS MOSTRARON UNA MEJORA EN LA SENSITIVIDAD Y UNIFORMIDAD PARA LA ANTENA DE FIGURAS CONCENTRICAS. SE OBTUVIERON IMAGENES DE FANTOMA Y CEREBRALES CON UN SISTEMA CLINICO DE RESONANCIA MAGNETICA DE 1.5 TESLAS, MOSTRANDO UNA BUENA CALIDAD DE IMAGEN. ESTE TIPO DE ANTENAS PUEDEN SER USADAS EN SISTEMAS CLINICOS Y CON SECUENCIAS CONVENCIONALES. Abstract A SURFACE COIL FOR MRI CONSISTED OF TWO CONCENTRIC LOOPS WAS DEVELOPED TO PRODUCE BRAIN IMAGES WITH A COMMERCIAL MR IMAGER. PRIOR TO BUILD THE COIL PROTOTYPE, THE MAGNETIC FIELD (B1) GENERATED BY THE COIL WAS NUMERICALLY SIMULATED. THIS FIELD SIMULATION IS BASED ON THE BIOT-SAVART LAW FOR THE CIRCULAR- AND SQUARE-SHAPED LOOP COILS. FROM THESE THEORETICAL RESULTS, WE CAN APPRECIATE AN IMPROVEMENT ON THE B1 HOMOGENEITY. COMPARISON OF EXPERIMENTAL SNR FOR A SINGLE-LOOP AND DUAL CONCENTRIC FIGURE COILS SHOW THAT THE LATTER HAS BETTER SENSITIVITY AND UNIFORMITY. PHANTOM AND BRAIN IMAGES WERE OBTAINED ON A 1.5 TESLA CLINICAL IMAGER, AND SHOWED A GOOD IMAGE QUALITY. THESE BRAIN IMAGES WHEN COMPARED AGAINST IMAGES OBTAINED WITH A CIRCULAR-SHAPED COIL EXHIBIT A BETTER CAPABILITY OF PENETRATION. THIS RECEIVER COIL CAN GENERATE HIGH QUALITY BRAIN IMAGES. THIS COIL DESIGN CAN BE USED IN CLINICAL IMAGERS AND IS COMPATIBLE WITH CONVENTIONAL IMAGING SEQUENCES AND PROTOCOLS.