Identification and mitigation of interference sources present in SSB-based wireless MRI receiver arrays

Single sideband amplitude modulation (SSB) is an appealing platform for highly parallel wireless MRI detector arrays because the spacing between channels is ideally limited only by the MRI signal bandwidth. However this assumes that no other sources of interference are present outside that bandwidth. This work investigates the practical interference between multiple SSB-encoded MRI signals.

Noise from coil preamplifiers and carrier bleed-through are identified as sources of interference. Two different SSB systems were designed for 1.5 T with different noise filtering properties. We show how the differences between the filtered noise profiles impact the received MR signal's dynamic range (DRsig ) and image signal-to-noise ratio through simulation, bench measurements, and phantom imaging experiments.

When operating individually in the MR scanner, both SSB systems were shown to minimally impact the original DRsig and signal-to-noise ratio. Conversely, when all eight channels were operating simultaneously, an average signal-to-noise ratio loss was observed to be 12% in the one system, while a second system with more complex filtering was able to achieve a 3% loss in signal-to-noise ratio.

Successful wireless transmission of multiple SSB-encoded MRI signals is possible as long as channel interference is properly managed through design and simulation.