Epigenetic MRI: Noninvasive imaging of DNA methylation in the brain

Proceedings of the National Academy of Sciences · 2022 · 10 citations

• Biology
• Neuroscience
• Computational biology

C-labeling of brain DNA. We also discovered strong regional differences in global DNA methylation. Just as functional MRI measurements of regional neuronal activity have had a transformational effect on neuroscience, we expect that the eMRI signal, both as a measure of regional epigenetic activity and as a possible surrogate for regional gene expression, will enable many new investigations of human brain function, behavior, and disease.

Enhancing linguistic research through 2‐mm isotropic <scp>3D</scp> dynamic speech MRI optimized by sparse temporal sampling and low‐rank reconstruction

Magnetic Resonance in Medicine · 2022 · 21 citations

• Computer Science
• Artificial Intelligence
• Computer Science

PURPOSE: To enable a more comprehensive view of articulations during speech through near-isotropic 3D dynamic MRI with high spatiotemporal resolution and large vocal-tract coverage. METHODS: Using partial separability model-based low-rank reconstruction coupled with a sparse acquisition of both spatial and temporal models, we are able to achieve near-isotropic resolution 3D imaging with a high frame rate. The total acquisition time of the speech acquisition is shortened by introducing a sparse temporal sampling that interleaves one temporal navigator with four randomized phase and slice-encoded imaging samples. Memory and computation time are improved through compressing coils based on the region of interest for low-rank constrained reconstruction with an edge-preserving spatial penalty. RESULTS: spatial resolution, 64-mm through-plane coverage, and a 35.6-fps temporal resolution are achieved. Investigations and analysis on specific speech samples support novel insights into nonsymmetric tongue movement, velum raising, and coarticulation events with adequate visualization of rapid articulatory movements. CONCLUSION: Three-dimensional dynamic images of the vocal tract structures during speech with high spatiotemporal resolution and axial coverage is capable of enhancing linguistic research, enabling visualization of soft tissue motions that are not possible with other modalities.

Articulatory and acoustic correlates of pharyngealization and pharyngealization spread in Cairene Arabic: A real-time magnetic resonance imaging study

2021

• Acoustics
• Linguistics
• Medicine

Articulatory and acoustic correlates of pharyngealization andpharyngealization spread in Cairene Arabic

Studies in Arabic linguistics · 2021 · 1 citations

• Computer Science
• Speech recognition
• Linguistics

Abstract Pharyngealized speech sounds in Arabic are articulated with a secondary posterior constriction and a lowered tongue body. This articulatory configuration spreads to adjacent and neighboring segments and has the acoustic consequence of lowering F2 in affected vowels. This study demonstrates that real-time Magnetic Resonance Imaging (rtMRI) can be successfully used to examine the role of (1) vowel length and (2) direction of spread in the extent of the articulatory modifications that occur in the segments to which pharyngealization spreads. Parallel acoustic measurements are also acquired to examine and compare the extent of modifications in formant frequencies. Results from both articulatory and acoustic data demonstrate that the extent of pharyngealization spread significantly varies with respect to these two factors.