Research Interests
The main thrusts of my research are the development of new methods that use
ultrasonic waves to interrogate previously unexplored tissue properties, the
development of new signal processing methods to enhance ultrasound image quality,
and the development of novel system hardware to enable new experimental approaches
or open new realms of clinical application.
In one project, termed radiation force imaging, we utilize a series of ultrasonic
pulses to apply local forces within tissue. We then process the echoes received
from these pulses to measure the viscoelastic response of the tissue. This data
forms the basis of a number of new image types that depict the complex mechanical
properties of tissues in vivo. This technique has shown early potential for
imaging the vitreous body of the eye to predict future retinal detachment and
for performing dynamic measurement of blood clot formation.
In another project we utilize a software-modified clinical GE scanner to interrogate
the angular scatter properties of tissue. We electronically move the transmit
and receive apertures in equal and opposite directions to obtain data at a variety
of scattering angles, while maintaining a uniform system response across angles
to enable coherent processing. This technique offers a new source of contrast
in soft tissues and has shown the potential to improve the visualization of
calcification.
In two other projects we are applying techniques from the realm of statistical
signal processing to speed and enhance ultrasound beamformer design and to improve
ultrasound image resolution and contrast through adaptive imaging.
We have two active projects in the area of hardware development. In the first
we are modifying a Philips SONOS 5500 imaging system to enable simultaneous
acquisition of data from all 128 channels of this phased array scanner, over
a period of more than one cardiac cycle. Once complete, we will be the only
research group in the world with this capability. We anticipate that such data
will open a broad array of signal processing approaches. In another project
we are working to develop an integrated beamformer capable of addressing a fully
populated 1024 element array. The high level of integration used in this system
will enable production at an extremely low cost and will open new realms of
clinical application.
For additional information about ultrasound technology at The University of
Virginia, please check the Web site for the Virginia
Medical Ultrasound Technology Group.
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