Meeting Banner
Abstract #4380

Analysis of the Effect of an External High Dielectric Sleeve on the Performance of a Head Coil at 128 MHz

Bu S. Park1, Joshua W. Guag1, Leonardo M. Angelone1, Sunder S. Rajan1

1CDRH/DP, FDA, Silver Spring, MD, United States

We present experimental and numerical simulation results showing that high dielectric materials (HDMs) located outside of a RF head coil decrease the electric field (E-field, |E|) with minimum change of the RF magnetic field (B1+) at 3T MRI imaging. Compared to previous research using HDMs located between the RF coil and sample, our method locating the HDM outside the coil allowed an increased sample size and more flexibility of HDM thickness optimization. Numerical simulation results showed more than 30% decrease in the local SAR at the boundary region of the head model. Validating experimental results showed a 21% decrease in the maximum |Etotal| using a HDM made of distilled water.

Abstract PDF Presentation Video

Keywords

absorbed absorption allowing amplifier apparent available axis barium becomes birdcage built calculation calculations caused central challenges circularly close coil coils college column commercially compartment component conductivity conservative consistent construction coronal correspond cylindrical decrease decreased design diameter dielectric direct disposed distilled domain donut edge electric electromagnetic engineering equal expected experiment experimental experimentally external field fields finite flexibility forward future generates geometry guide head house human improvement inner input inside introduced isotropic length local located locating loss made mainly material materials measured measuring model modeled namely near noise normalization normalized numerical obvious ongoing optimization optimized oriented outside parallel park partially partner peak performance placed potential power previous reduced reduction related resolution respectively ring robot rods sample scalar shaped shield shielding silver simple simulation simulations sleeve slices slightly smaller software space spring strong strontium sunder surface temperature thereby third tissue titanate transverse types useful verified violet water watts whereas whole wind winding yang yellow