Principle, Applications and Limitations of Ultrasound Elastography
Mechanical properties of biological tissue are of histological relevance because of a correlation between palpable lesions (e.g. nodes) and malignant tumors. The majority of cancerous lesions can be palpated as hard inclusions, at least after they have reached a certain size. However, there are also benign changes in tissue, which tend to be harder compared to surrounding tissue. As manual palpation is limited to the skills of the examiner and contributes only subjective and qualitative information, an imaging modality could be helpful, which provides the examiner with objective and quantitative information about mechanical properties of the examined tissue. Medical ultrasound imaging systems allow a visualization of internal mechanical tissue displacements caused by external surface forces or by induced internal forces. The spatial distribution of internal strain can be derived from tissue displacements to get so called “elastograms” , which lead to a visualization of both, the location and size of stiff tissue areas.
KeywordsAxial Strain Strain Image Time Delay Estimate Hard Inclusion Virtual Reality Application
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