title: Identification and mitigation of interference sources present in SSB-based wireless MRI receiver arrays.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Successful wireless transmission of multiple SSB-encoded MRI signals is possible as long as channel interference is properly managed through design and simulation.
authors: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA.
authors: Matthew J
authors: MJ
authors: Riffe
authors: Michael D
authors: MD
authors: Twieg
authors: Natalia
authors: N
authors: Gudino
authors: Colin J
authors: CJ
authors: Blumenthal
authors: Jeremiah A
authors: JA
authors: Heilman
authors: Mark A
authors: MA
authors: Griswold
mesh_terms: D000669:Amplifiers, Electronic; D016477:Artifacts; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008280:Magnetics / Q000295:instrumentation*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D059629:Signal-To-Noise Ratio; D014159:Transducers; D059015:Wireless Technology / Q000295:instrumentation*
keywords: frequency multiplexing; magnetic resonance imaging; single sideband amplitude modulation; wireless link