(provided by candidate): Through this award, a researcher with a background in physics and acoustics will receive additional training and conduct research in diagnostic ultrasound. Structured training in clinical research practice will be provided through a sequence of courses, especially related to training in biostatistics and human disease. Training in current quantitative research methods will be provided through the research portion of this proposal, which examines the accuracy of nonlinear propagation computer models when applied to tissue mimicking media. Recent progress in numerical modeling of nonlinear acoustic fields has created efficient algorithms to simulate pulsed fields from array transducers. However, few results of acoustic field parameters have been reported for measurements conducted in media with tissue-like properties. A newly developed, stable tissue-mimicking liquid (TM) will be used to test the accuracy of these efficient algorithms that include nonlinear propagation effects. The hypothesis of this proposal is that numerical models that incorporate nonlinear propagation effects will provide accurate representation of the acoustic fields of diagnostic ultrasound devices. The results will be useful to improve simulations of ultrasonic fields that are used to develop and optimize ultrasonic imaging applications and in the determination of acoustic output indices. Measurements of the acoustic field amplitude propagating in TM liquid will be compared to results of numerical models to address three specific aims: 1) Comparison of numerical models and measurements in TM liquid with attenuation coefficient of 0.30 dB/cm/MHz to assess accuracy of current derating scheme. 2) Investigation of proposed methods of """"""""linearizing"""""""" acoustic output methodology by conducting measurements at low output levels and extrapolating to high output levels to avoid nonlinear effects. 3) Assessment of accuracy of numerical methods for models related to imaging: TM liquids with greater attenuation coefficient, including 0.5 and 0.7 dB/cm/MHz, obstetrical, and other tissue models.
| Stiles, Timothy A; Madsen, Ernest L; Frank, Gary R (2008) An exposimetry system using tissue-mimicking liquid. Ultrasound Med Biol 34:123-36 |
