Accelerated 3D MRI of vocal tract shaping using compressed sensing and parallel imaging

3D MRI of the upper airway has provided valuable insights into vocal tract shaping and data for the modeling of speech production. Small movements of articulators can lead to large changes in the produced sound, therefore improving the resolution of these datasets, within the constraints of a sustained sound (6-12 seconds), is an important area for investigation. This paper provides the first application of compressed sensing (CS) with parallel imaging to high-resolution 3D upper airway MRI. We use spatial finite difference as the sparsifying transform, and investigate the use of high-resolution phase information as a constraint during CS reconstruction. In a retrospective subsampling experiment with no sound production, 5x undersampling produced acceptable image quality when using phase-constrained CS reconstruction. The prospective use of this accelerated acquisition enabled 3D vocal-tract MRI during sustained production of English /s/,/int/,/i/,/r/ with 1.33times1.33times1.33-mm³ spatial resolution and 10-seconds of scan time.