In the present funding period of this project, we have accomplished the following tasks. 1. We have demonstrated that it is possible to produce images (elastograms) of good objective quality from phantoms and tissue sin vivo and in vitro using a slightly modified commercial ultrasound scanner. 2. It has been demonstrated that reliable elastic modulus contrast exists in normal tissue component and in tumors; 3. The scientific foundations of the mechanical, mathematical, statistical, acoustical and signal processing issues involved in the production of quality elastograms have been elucidated and upper performance bounds have been calculated. Numerous new tools have been developed to improve the tradeoffs among the relevant parameters. In this renewal application, our hypothesis is that significant improvements to elastograms may be obtained by using our knowledge about basic elastic tissue properties and about the elastographic image formation process. In order to test this hypothesis, we propose the specific aims shown below.
Aims 1 through 3 are designed to further improve on the objective quality of the elastograms and to derive additional relevant information from them;
aims 4 and 5 strive to increase our understanding of basic tissue mechanical properties, and to investigate the practical issues involved in imaging them.
Aim 1. Investigate the theoretical and practical aspects of elastographic texture in software, phantom models and tissues. Relate elastographic texture (modulus and strain) to actual stiffness texture.
Aim 2. Investigate acquisition and signal processing strategies for improving objective elastographic image parameters.
Aim 3. Investigate the theoretical and practical issues involved in the imaging of axial and lateral tissue strains, tissue Poisson's ratios, and in applying corrections of elastograms for motions in orthogonal directions.
Aim 4. Continue to investigate the basic elastic behavior of tissues (Baylor subcontract).
Aim 5. Develop an Incoherent Spectral Strain Estimation technique and its applications to elastography in noisy environments.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Program Projects (P01)
Project #
5P01CA064597-07
Application #
6347366
Study Section
Subcommittee G - Education (NCI)
Project Start
2000-08-28
Project End
2001-05-31
Budget Start
Budget End
Support Year
7
Fiscal Year
2000
Total Cost
$279,759
Indirect Cost
City
Houston
State
TX
Country
United States
Zip Code
77225
Thittai, Arun K; Yamal, Jose-Miguel; Ophir, Jonathan (2013) Small breast lesion classification performance using the normalized axial-shear strain area feature. Ultrasound Med Biol 39:543-8
Thittai, Arun K; Yamal, Jose-Miguel; Mobbs, Louise M et al. (2011) Axial-shear strain elastography for breast lesion classification: further results from in vivo data. Ultrasound Med Biol 37:189-97
Thittai, Arun K; Galaz, Belfor; Ophir, Jonathan (2011) Visualization of HIFU-induced lesion boundaries by axial-shear strain elastography: a feasibility study. Ultrasound Med Biol 37:426-33
Thittai, Arun K; Galaz, Belfor; Ophir, Jonathan (2010) Axial-shear strain distributions in an elliptical inclusion model: experimental validation and in vivo examples with implications to breast tumor classification. Ultrasound Med Biol 36:814-20
Patil, Abhay V; Krouskop, Thomas A; Ophir, Jonathan et al. (2008) On the differences between two-dimensional and three-dimensional simulations for assessing elastographic image quality: a simulation study. Ultrasound Med Biol 34:1129-38
Garra, Brian Stephen (2007) Imaging and estimation of tissue elasticity by ultrasound. Ultrasound Q 23:255-68
Doyley, Marvin M; Srinivasan, Seshadri; Dimidenko, Eugene et al. (2006) Enhancing the performance of model-based elastography by incorporating additional a priori information in the modulus image reconstruction process. Phys Med Biol 51:95-112
Hoyt, Kenneth; Forsberg, Flemming; Ophir, Jonathan (2006) Comparison of shift estimation strategies in spectral elastography. Ultrasonics 44:99-108
Hoyt, Kenneth; Forsberg, Flemming; Ophir, Jonathan (2006) Analysis of a hybrid spectral strain estimation technique in elastography. Phys Med Biol 51:197-209
Chandrasekhar, R; Ophir, J; Krouskop, T et al. (2006) Elastographic image quality vs. tissue motion in vivo. Ultrasound Med Biol 32:847-55

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