Abstract #0287

Parallel Transmit Excitation at 1.5 T Based on the Minimization of a Driving Function for Device Heating

Natalia Gudino¹,², Merdim Sonmez², Anthony Z. Faranesh², Robert J. Lederman², Robert S. Balaban², Michael Schacht Hansen², Mark A. Griswold¹,³

¹Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States; ²Division of Intramural Research, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States; ³Department of Radiology, Case Western Reserve University, Cleveland, OH, United States

A transmit planar coil array driven by near-coil current-source amplifier was implemented in iMRI setup to reduce the RF E-field coupling and consequent heating in a wire/guidewire. An optimum set of phases was obtained through minimization of a driving function (W) for device heating and tested in a MRI phantom and animal experiments. Up to 92 % temperature reduction was measured at the tip of the device when transmitting with the array in an optimum phase configuration instead of using the conventional body coil transmitter. B1 constrained minimization of W at predefined ROIs was proposed and tested on the benchtop.