BME Seminar: Dan Benjamini
Monday, September 19th, 2022
12:00 p.m.
Dan Benjamini
Stadtman Investigator
Chief, Multiscale Imaging and Integrative Biophysics Unit
Laboratory Of Behavioral Neuroscience
National Institute on Aging, Intramural Research Program
"Imaging Microscopic Neuropathological Processes Using Model-Free Analysis of Diffusion and Relaxation MRI"
Keating 103
Zoom Link | Passcode: BearDown
Hosts: Dr. Beth Hutchinson and Dr. Shang Song
(Permission required for enrolled students to attend via Zoom)
Persons with a disability may request a reasonable accommodation by contacting the Disability Resource Center at 621-3268 (V/TTY).
ABSTRACT:
A fundamental obstacle for using magnetic resonance imaging (MRI) to detect microscopic tissue alterations such as gliosis and diffuse axonal injury is the averaging that occurs across the image volume elements, i.e., voxels, or in other words – MRI’s limited spatial resolution. Although relaxation and diffusion contrast mechanisms carry information that can be 100-1000 times below the nominal MRI resolution, voxel-averaged images "flatten" any intra-voxel heterogeneity leading to loss in sensitivity and specificity. In a mammalian brain, an individual voxel can contain multiple chemical and physical microenvironments with neurons, axons, glia, myelin, and cerebrospinal fluid. Many neuropathological processes of interest are microscopic in nature and affect only certain cellular components. These tend to occupy a small volume fraction of any given voxel, which makes them undetectable using voxel-averaged MRI methods.
Benjamini will discuss acquisitions that maximize the amount of information in an image by using a combination of magnetic field profiles to probe relaxation and diffusion mechanisms simultaneously; an approach to resolve sub-voxel information by modeling the signal as multiexponential; and finally, strategies to refine the ensuing abundance of high-dimensional information, and sort and recover biologically relevant details into actionable biomarker images.
BIO:
After finishing his undergraduate and master’s degrees in biomedical engineering at Israel’s Tel Aviv University, Dan Benjamini moved to the U.S. in 2012, where through a National Institutes of Health (NIH) special program he was able to complete his doctoral studies in the lab of Peter Basser in 2015. He was a postdoctoral visiting Fellow with Peter Basser from 2015 to 2018, and then a staff scientist at the Neuroradiology–Neuropathology Integration Core of the Center for Neuroscience and Regenerative Medicine from 2018 to 2021. In 2021, Dr. Benjamini obtained the Stadtman Investigator Award at NIH. He is currently serving as a tenure-track principal investigator and the chief of the Multiscale Imaging and Integrative Biophysics (MiiB) Unit at the National Institute on Aging (NIA).