Assistant Professor, Psychiatry and Medical Physics
Associate Professor, Biostatistics and Medical Informatics
“Atypical development of white matter microstructure of the corpus callosum in males with autism: a longitudinal investigation.” (Travers, et al. March 2015, Molecular Autism).
Fractional anisotropy measures plotted as a function of age and group. ASD, autism spectrum disorder; TDC, typically developing controls. Time 1 scatter has been adjusted for the head coil changes, and the overlaid growth models for each group represent the generalized additive mixed model spline curves (with dashed 95% confidence intervals), controlling for head coil changes, total motion index, signal-to-noise ratio, and random effects.
“Hyperspherical harmonic (HyperSPHARM) representation of surface anatomy: a holistic treatment of multiple disconnected anatomical structures.” (Hosseinbor, et al. March 2015, Medical Image Analysis).
We present a novel surface parameterization technique using 4D hyperspherical harmonics in representing multiple disjoint objects as a single analytic function, terming it HyperSPHARM. The underlying idea behind HyperSPHARM is to stereographically project an entire collection of disjoint 3D objects onto the 4D hypersphere and subsequently simultaneously parameterize them with the 4D hyperspherical harmonics. In an imaging dataset of healthy adult human brains, we apply HyperSPHARM to the hippocampi and amygdalae.
“MPnRAGE: A technique to simultaneously acquire hundreds of differently contrasted MPRAGE images with applications to quantitative T(1) mapping.” (Kecskemeti, et al. April 2015, Magnetic Resonance in Medicine).
Example images from MPnRAGE displaying a variety of T1w contrasts. Frame 1: The earliest inversion time possible. Frame 45: Image with nulled white matter. Frame 73: Image with nulled gray matter. Frame 118: Image with nulled cerebral spinal fluid. Frame 240: The longest possible inversion time. Composite: image formed by summation of all the data.
The Brain Imaging Core is central to the integration of behavioral and biological research at the Waisman Center IDDRC. Mental retardation and developmental disabilities, whether resulting from environmental factors or genetic factors, involve a pathological alteration of brain structure and/or function. Examination of such alterations is critical to our understanding of the causal pathways from environmental or genetic processes to behavioral outcome and for the development of preventive or ameliorative interventions.