Diffusion Tensor and q-Space MRI Specimen Characterization


Diffusion Tensor MRI (DTI or DT-MRI) – a technique described in U.S. Patent 5,539,310 and implemented by all major commercial MRI systems – provides information primarily about how water diffuses in the extracellular compartment of tissues, where water mobility is hindered (i.e., where water diffuses freely but encounters barriers from which it is reflected). However, DTI does not provide a complete characterization of diffusion in the intracellular compartment of some cells, particularly myelinated axons, where water mobility is restricted by impermeable membranes (i.e., where water is trapped but otherwise free to diffuse within the cell).

The subject invention provides a new modeling framework that self-consistently describes 3-D anisotropic diffusion within a hindered extracellular compartment and within a restricted intra-axonal compartment. It results in an improved characterization and measurement tissue and cell microstructure in neuronal tissue, which promises to advance diagnosis of neurological conditions (e.g., Stroke, MS, Alzheimer’s disease), possibly cognitive and behavioral disorders (e.g., schizophrenia), as well as our ability to follow normal development and aging processes.

More specifically, this new in vivo diffusion MRI method, especially suited for the characterization of brain white matter, marries q-space and DTI concepts: Diffusion within axons is modeled as hindered diffusion parallel to the axis of the axon, and restricted diffusion perpendicular to the axis. Diffusion exterior to axons is modeled as hindered diffusion with differing diffusivities parallel and perpendicular to the nerves’ axis. To practice this method, diffusion weighted (DW) MRI data are acquired from specimens at different q-values (with different diffusion gradient magnitudes and directions). Parameters associated with tissue microstructure, such as the intra and extra-axonal principal diffusivities and their corresponding principal directions, and the volume fractions of intra and extra-axonal space are then estimated from these data. Improved angular resolution of fiber tract orientation can be obtained for tractography studies and more microstructural information can be gleaned for both diagnostic and therapeutic purposes than from conventional DTI. This technology has been named CHARMED (Composite Hindered and Restricted Model of Diffusion).

A detailed announcement describing the licensing opportunity for this and related technologies referenced below was published in the Federal Register on Tuesday, April 14, 2009 (74 FR 17199-17201).

Development Stage:
Invention is fully developed.

Related Invention(s):
E-203-1993-0
E-079-2003-1
E-276-2008-0


Inventors:

Peter Basser (NICHD)  ➽ more inventions...

Yaniv Assaf


Intellectual Property:
U.S. Pat: 7,643,863 issued 2010-01-05
US Application No. 10/888,917
PCT Application No. PCT/US2004/22027
US Application No. 60/571,064

Publications:
Assaf Y, et al. PMID 15508168
Assaf Y, Basser PJ. PMID 15979342
Avram L, et al. PMID 18574856
Bar-Shir A, et al. Experimental Parameters and Diffraction Patterns at High q Diffusion MR: Experiments and Theoretical Simulations. Proc Intl Soc Mag Reson Med. 2007;15:1530. PDF

Collaboration Opportunity:

The Eunice Kennedy Shriver National Institute of Child Health and Human Development, Section on Tissue Biophysics and Biomimetics, is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize novel MRI methods to probe tissue structure and organization, particularly for neuroimaging applications. Please contact Alan Hubbs, Ph.D. at 240-276-5532 or hubbsa@mail.nih.gov for more information.


Licensing Contact:
Charlotte McGuinness, Ph.D., J.D.
Email: cm432k@nih.gov
Phone: 240-276-5530

OTT Reference No: E-079-2003-0
Updated: Sep 15, 2015