The broad long-term objective of the research in this revised application is to develop completely noninvasive ultrasound-guided phased-array applicator systems for, a range of therapeutic applications, e.g., hyperthermia, rapid-heating hyperthermia, and tissue ablation. Our preliminary research results indicate that noninvasive measurement of changes in tissue temperature is feasible using standard diagnostic ultrasound pulse-echo data and appropriate digital signal processing (DSP) algorithms. We have experimentally verified that changes in tissue temperatures can be estimated accurately and with high spatial resolution by estimating frequency shifts in the spectrum of the RF pulse-echo data at a specified location. Furthermore, noninvasive acoustic feedback for focusing and target (tumor) tracking through tissue inhomogeneities is also feasible. This, however, requires the development of new phased- array applicator systems capable of transmit-receive operation. Transmit- receive capability will give phased-array applicators the ability to self focus in the presence of tissue inhomogeneity in a similar manner to imaging arrays currently used in practice. Self-focusing of therapeutic arrays, while similar in principle to self-focusing of imaging arrays,, does present some new challenges. We intend to develop self-focusing algorithms for optimal therapeutic arrays. Noninvasive measurement of temperature changes and self-focusing capability of therapeutic applicators coupled with guidance using real-time ultrasound imaging systems will undoubtedly provide an attractive system for diathermy and tissue ablation (surgery). The versatility, low cost, and low morbidity associated with noninvasive ultrasonic procedure will have a positive impact on the health care delivery for a significant number of patient groups, e.g., breast cancer, prostate cancer, and liver cancers.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29CA066602-05
Application #
2882415
Study Section
Special Emphasis Panel (ZRG7-DMG (01))
Program Officer
Stone, Helen B
Project Start
1996-03-15
Project End
2001-02-28
Budget Start
1999-03-01
Budget End
2000-02-29
Support Year
5
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
168559177
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Liu, Dalong; Ebbini, Emad S (2010) Real-time 2-D temperature imaging using ultrasound. IEEE Trans Biomed Eng 57:12-6
Ballard, John R; Casper, Andrew J; Wan, Yayun et al. (2010) Adaptive transthoracic refocusing of dual-mode ultrasound arrays. IEEE Trans Biomed Eng 57:93-102
Liu, Dalong; Ebbini, Emad S (2009) Real-time two-dimensional temperature imaging using ultrasound. Conf Proc IEEE Eng Med Biol Soc 2009:1971-4
Wan, Yayun; Ebbini, Emad S (2008) Imaging with concave large-aperture therapeutic ultrasound arrays using conventional synthetic-aperture beamforming. IEEE Trans Ultrason Ferroelectr Freq Control 55:1705-18