Extending real-time MRI of the oral cavity using simultaneous multislice and compressed sensing.

Purpose: To demonstrate a real-time MRI (rtMRI) sequence that can image multiple slices simultaneously and apply them to image the dynamics of the oral cavity. Specifically, we demonstrate the imaging of tongue movement, speech, and swallowing.

Methods: We developed a radial rtMRI sequence with multiband excitation. Two sampling schemes were explored: a golden-angle trajectory and a golden-angle trajectory adapted for simultaneous multislice acceleration. Additionally, we developed a compressed sensing reconstruction pipeline. Phantom and in vivo rtMRI data were acquired on a 3 T system using a standard head/neck coil.

Results: We show that the proposed technique can acquire rtMRI videos at a range of temporal resolutions (up to 25 ms). Example applications of tongue movement, speech, and swallowing are shown. Additionally, we show that the sequence is robust to changes in slice distance and coil compression level.

Conclusion: Combining rtMRI with multiband excitation and compressed sensing reconstruction enables imaging of the oral cavity at high (up to 25 ms) temporal resolution.