The determination of the nature of diffuse liver diseases is important in determining patient management. At present, only invasive and limited noninvasive methods are available for reliable diagnosis. The purpose of this proposal is to demonstrate the feasibility of identification and differentiation of normal and diffusely diseased livers in vivo using noninvasive ultrasonic pulse echo methods. Specifically, this is achieved by measuring the nonlinear frequency dependent attenuation parameters of these tissues. Our preliminary studies show that it is possible to differentiate between normal and certain diffuse liver conditions based on the nonlinear attenuation parameters, which we have shown to be related to the basic absorption and scatterning properties of these tissues. The measurements will first be performed on a large number of in vitro liver samples. A reference archive of liver attenuation parameters and their respective pathologies will be collected. Thereafter, these tissue parameters will be measured in vivo using a computer based system. This instrument will be tested using tissue mimicking phantoms whose nonlinear attenuation parameters can be varied in a controlled way. This is necessary in order to experimentally determine the smallest measurable changes in these parameters. The in vivo attenuation values of the livers will be compared to the previously archived values obtained from the in vitro studies. A tentative identification of the disease will then be made. The nature of the disease will be independently verified. Thus, quantitative ultrasonic techniques developed here would be clinically useful for improved diagnosis.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA038515-03
Application #
3176579
Study Section
Diagnostic Radiology Study Section (RNM)
Project Start
1985-08-01
Project End
1989-07-31
Budget Start
1987-08-01
Budget End
1989-07-31
Support Year
3
Fiscal Year
1987
Total Cost
Indirect Cost
Name
University of Texas Health Science Center Houston
Department
Type
Schools of Medicine
DUNS #
City
Houston
State
TX
Country
United States
Zip Code
77225
Kallel, F; Ophir, J; Magee, K et al. (1998) Elastographic imaging of low-contrast elastic modulus distributions in tissue. Ultrasound Med Biol 24:409-25
Garra, B S; Cespedes, E I; Ophir, J et al. (1997) Elastography of breast lesions: initial clinical results. Radiology 202:79-86
Alam, S K; Ophir, J (1997) On the use of envelope and RF signal decorrelation as tissue strain estimators. Ultrasound Med Biol 23:1427-33
Konofagou, E E; Ophir, J; Kallel, F et al. (1997) Elastographic dynamic range expansion using variable applied strains. Ultrason Imaging 19:145-66
Kallel, F; Ophir, J (1997) A least-squares strain estimator for elastography. Ultrason Imaging 19:195-208
Kallel, F; Varghese, T; Ophir, J et al. (1997) The nonstationary strain filter in elastography: Part II. Lateral and elevational decorrelation. Ultrasound Med Biol 23:1357-69
Alam, S K; Ophir, J (1997) Reduction of signal decorrelation from mechanical compression of tissues by temporal stretching: applications to elastography. Ultrasound Med Biol 23:95-105
Varghese, T; Ophir, J (1997) The nonstationary strain filter in elastography: Part I. Frequency dependent attenuation. Ultrasound Med Biol 23:1343-56
Konofagou, E; Dutta, P; Ophir, J et al. (1996) Reduction of stress nonuniformities by apodization of compressor displacement in elastography. Ultrasound Med Biol 22:1229-36
Varghese, T; Ophir, J (1996) Estimating tissue strain from signal decorrelation using the correlation coefficient. Ultrasound Med Biol 22:1249-54

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