Tunable Resonant Actuation for Magnetic Resonance Elastography of Active Tissues

Abstract

This project will develop a multi-actuator oscillator and its tuning method to realize enhanced magnetic resonance elastography (MRE) of the intervertebral disc (IVD). The IVD is an important target for medical imaging because of its relevance in disc degeneration, a significant pathology in both military and civilian populations. As of now, MRE technology is limited to softer tissues, such as the liver and brain; the proposed project will develop new technology to solve this problem. MRE is a medical diagnostic tool used to measure the stiffness of human tissue in vivo indirectly. This technique involves the generation of shear waves in the tissue and the magnetic resonance imaging (MRI) of these resulting shear waves to compute parameters defining the resistance of the tissue to deformation. A recent focus has been acquiring stiffness maps of the IVD where the stiffness of the nucleus pulposus can be used as a biomarker for disc degeneration. The IVD is a flexible pad located in between each vertebra and acts as a shock absorber for the spine. The disc is composed of a tough outer ring known as the annulus fibrosus and the nucleus pulposus, a soft gel like material located in the middle of the disc. When the disc experiences high pressure, small tears may occur as well as thinning along the annulus fibrosus. These structural changes lead to the nucleus pulposus drying out, causing a loss of flexibility and thus degeneration. In order to better diagnose these pathological changes in the IVD, an MR-compatible actuation mechanism that allows for the proper determination of the disc’s stiffness is required. The developed technology will break the technical barrier, i.e., a lack of advanced actuation technology usable in a magnetic resonance imaging scanner, which currently prevents high resolution elastography of small tissues such as the IVD. The project will develop tunable high frequency actuators for use in the MRI, along with a tuning method for adjusting actuation parameters to individual patients. The success of the proposed research will provide new tools for early diagnosis of degenerative disc disease and effective treatment strategies for spine surgery. The project outcomes may have a long-term impact on the quality of life of millions of Americans by improving mobility and independence.

Document Details

Document Type
DoD Grant Award
Publication Date
Mar 10, 2021
Source ID
W81XWH2010043

Entities

People

  • Jun Ueda

Organizations

  • Georgia Tech Research Corporation
  • United States Army

Tags

Readers

  • Neurotrauma and Rehabilitation Medicine.
  • Robotics and Automation.
  • Structural Dynamics.