James F. Greenleaf, Ph.D., and his colleagues study methods of measuring tissue properties using noninvasive, simple, high-speed ultrasound scanners. Vibro-acoustography and shear wave methods are used to assess the mechanical properties of tissue and its stiffness and viscosity. The methods produce images (ultrasonic biopsies) of tissues and organs.
A software upgrade would equip ultrasound scanners around the world with the technology to provide simple, noninvasive biopsies at the patient's bedside. Dr. Greenleaf and collaborators have recently licensed the intellectual property that will make this possible to a major manufacturer.
Dr. Greenleaf and colleagues have tested vibro-acoustic methods in several organ systems. This testing includes:
- Studying variations in stiffness of muscles in patients with stroke
- Determining that skin stiffness varies with skin disease progression and regression
- Noting variations in viscoelastic properties of kidneys with different disease states
- Measuring variations in stiffness of the heart wall during the heart cycle
- Measuring fundamental material properties of arteries by stimulating modes of vibration using radiation force of ultrasound
- Measuring tissue material properties using ultrasound-detected displacements within externally vibrated tissue
Significance to patient care
Because stiffness of tissue is highly associated with disease, Dr. Greenleaf and colleagues have developed and licensed modifications of ultrasound imaging instruments to make fast, inexpensive and noninvasive measurements of the elastic properties of tissues and organs, providing biomarkers for assessing many maladies in most of the world population.
- Distinguished Service Award (2007), Rayleigh Award (2004), Achievement Award (2003), Outstanding Paper Award (1992) and Distinguished Lecturer Award (1990-1991), IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society