An ultra-fast RF switch for 23Na SWIFT imaging at 10.5T

Motivation: The development and demonstration of zero echo time imaging (SWIFT) of Sodium (23Na) at 10.5T using a human-approved birdcage coil for imaging of sodium concentrations in the human brain, knee, and/or wrist. Goal(s): To achieve SWIFT imaging quality comparable to UTE for imaging of fast relaxing 23Na signal. Approach: Development of an ultra-fast PIN diode driver, switchable attenuator, and T/R switch with extremely high transmit-to-receive isolation to ensure isolation of the un-blanked RFPA noise. Results: Demonstrated herein are bench measurements of fast switching and high isolation of the hardware as well as MR images demonstrating the capability of the hardware. Impact: Enabling imaging of nuclei with fast relaxation times with custom-built fast-switching PIN drivers and RF frontend which features sub-microsecond switching speeds and isolations of up to 100 dB between transmit and receive.