Radiation force and shear motions in inhomogeneous mediaстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:An action of radiation force induced by ultrasonic beam in waterlike media such as biological tissues (where the shear modulus is small as compared to the bulk compressibility) is considered. A new nondissipative mechanism of generation of shear displacement due to a smooth (nonreflecting) medium inhomogeneity is suggested and the corresponding medium displacement is evaluated. It is shown that a linear primary acoustic field in nondissipative isotropic elastic medium cannot excite a nonpotential radiation force and hence a shear motion whereas even smooth inhomogeneity makes this effect possible. An example is considered showing that the generated displacement pulse can be significantly longer than the primary ultrasound pulse. It is noted that unlike the dissipative effect the nondissipative action on a localized inhomogeneity (such as a lesion in a tissue) changes its sign along the beam axis thus stretching or compressing the focus area.