Acoustical Nonlinearity and its Images in Biomedicine
نویسندگان
چکیده
Some acoustical nonlinear effects in biological media at medical ultrasonic frequencies and intensities were studied experimentally. The imaging method of acoustical nonlinearity parameter, as a basic parameter in nonlinear acoustics, was developed and investigated. Results indicate tidt the difference between normal and diseased tissues in nonlinearity parameter tomography is more sensitive than that in linear parameter tomography. ~erefore, the nonlinearity parameter tomography may become a novel imaging method for tissue characterization.
منابع مشابه
Research Progress on Application of Nonlinear Acoustics in Medical Imaging
In recent years many works have indicated that a series of interesting nonlinear acoustical effects have been observed in the range of biomedical intensities and frequencies. This new phenomenon in medical ultrasound has attracted immediate interest of many researchers. Two topics on this aspect will be presented in this paper. (1) The acoustical nonlinearity parameter imaging in reflection mod...
متن کاملDesign, Construction and Evaluation of an Anthropomorphic Head Phantom for Assessment of Image Distortion in Stereotactic Radiosurgery Planning Systems
Introduction: In recent years, the use of magnetic resonance (MR) images in radiation treatment planning has drawn considerable attention. However, although the extent of a tumor can be determined in great detail on MR images, the geometric accuracy of these images is limited by distortions stemming from the inhomogeneity of the static background magnetic field, the nonlineari...
متن کاملStress corrosion crack depth investigation using the time reversed elastic nonlinearity diagnostic.
Evidence of the ability to probe depth information of stress corrosion cracking (SCC) are presented using the time reversed elastic nonlinearity diagnostic (TREND). Depth estimation of SCC is important to determine when a stainless steel canister has been breached. TREND is a method to focus elastic energy to a point in space in order to probe that point for damage and its' depth penetration is...
متن کاملOn the nature of two-tone aural nonlinearity.
The present manuscript begins with a review of the literature on two-tone nonlinearity and proceeds to the description of an ad hoc model of auditory nonlinearity which can account for several of the features of the psychophysical data on various two-tone nonlinearities, in particular, (f2-f1), (2f1-f2), and two-tone suppression. The two basic components of the model are (1) a nonlinearity whic...
متن کاملAuditory filter nonlinearity in mild/moderate hearing impairment.
Sensorineural hearing loss has frequently been shown to result in a loss of frequency selectivity. Less is known about its effects on the level dependence of selectivity that is so prominent a feature of normal hearing. The aim of the present study is to characterize such changes in nonlinearity as manifested in the auditory filter shapes of listeners with mild/moderate hearing impairment. Notc...
متن کامل