Toric focusing for radiation force applications using a toric lens coupled to a spherically focused transducer
| Autor: | Matthew O'Donnell, Thu-Mai Nguyen, Bastien Arnal |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Physics
Absorption (acoustics) Acoustics and Ultrasonics medicine.diagnostic_test Phantoms Imaging Electromagnetic spectrum business.industry Transducers Work (physics) Imaging phantom Toric lens Optics Transducer medicine Elasticity Imaging Techniques Computer Simulation Elastography Electrical and Electronic Engineering business Instrumentation Mechanical index Lenses |
| Zdroj: | IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. 61:2032-2041 |
| ISSN: | 1525-8955 0885-3010 |
| Popis: | Dynamic elastography using radiation force requires that an ultrasound field be focused during hundreds of microseconds at a pressure of several megapascals. Here, we address the importance of the focal geometry. Although there is usually no control of the elevational focal width in generating a tissue mechanical response, we propose a tunable approach to adapt the focus geometry that can significantly improve radiation force efficiency. Several thin, in-house-made polydimethylsiloxane lenses were designed to modify the focal spot of a spherical transducer. They exhibited low absorption and the focal spot widths were extended up to 8-fold in the elevation direction. Radiation force experiments demonstrated an 8-fold increase in tissue displacements using the same pressure level in a tissue-mimicking phantom with a similar shear wave spectrum, meaning it does not affect elastography resolution. Our results demonstrate that larger tissue responses can be obtained for a given pressure level, or that similar response can be reached at a much lower mechanical index (MI). We envision that this work will impact 3-D elastography using 2-D phased arrays, where such shaping can be achieved electronically with the potential for adaptive optimization. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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