Compensation of Respiratory Induced Artifacts in the Lumbar Spinal Cord Using a 1D Pre-Acquisition Navigator

Motivation: Respiration induces artifacts and signal loss in axial multi-echo gradient echo imaging of the lumbar spinal cord. Goal(s): To investigate respiration-induced field shifts in the lumbar cord and to mitigate respiration induced artifacts using a 1D phase navigator. Approach: A 1D phase navigator, added prior to the multi-echo gradient echo readout, was used to measure and provide compensation for respiration-induced and shot-dependent phase shifts. Results: The proposed navigator was effective in measuring field shifts and providing a substantial reduction in artifacts in the lumbar spinal cord. Navigator post-processing was simplified compared to that required for a 1D navigator post-readout. Impact: This work demonstrates, via phantom and in-vivo experiments, self-consistent measurements of respiration-induced field shifts and proposes an approach for their compensation that could be integrated into future spinal cord studies using multi-echo gradient echo acquisitions.