https://scholars.lib.ntu.edu.tw/handle/123456789/481507
標題: | Cavitation-enhanced ultrasound thermal therapy by combined low- and high-frequency ultrasound exposure | 作者: | WEN-SHIANG CHEN Shih, T.-C. Win-Li Lin HAO-LI LIU J-S Chen YUNG-YAW CHEN |
關鍵字: | Cavitation-enhanced heating; Low-frequency ultrasound; Ultrasound thermal therapy | 公開日期: | 2006 | 卷: | 32 | 期: | 5 | 起(迄)頁: | 759-767 | 來源出版物: | Ultrasound in Medicine and Biology | 摘要: | This paper demonstrates a novel approach for enhancing ultrasound-induced heating by the introduction of acoustic cavitation using simultaneous sonication with low- and high-frequency ultrasound. A spherical focused transducer (566 or 1155 kHz) was used to generate the thermal lesions, and a low-frequency planar transducer (40 or 28 kHz) was used to enhance the bubble activity. Ex vivo fresh porcine muscles were used as the target of ultrasound ablation. The emitted signals and the signals backscattered from the bubble activity were also recorded during the heating process by a PVDF-type needle hydrophone, and thermocouples were inserted to measure temperatures. Compared with the lesions formed by a single focused transducer, the size of the lesions generated by this approach were as much as 140% larger along the axial direction and 200% larger along the radial direction for combined 566- and 40-kHz sonication. They were 47% and 66% larger along the axial and radial directions, respectively, for combined 1155- and 28-kHz sonication. Cavitation activities enhanced by low-frequency ultrasound were confirmed by the presence of subharmonics in the spectrum and temperature increase as a result of increased tissue absorption. These observations imply that cavitation-enhanced lesions can be generated without reducing the penetration ability; they also show the advantage of producing larger and more uniform thermal lesions by multiple sonications. This technique provides an easy and effective way to achieve cavitation-enhanced heating, and may be useful for generating large and deep-seated thermal lesions. (E-mail: yychen@cc.ee.ntu.edu.tw). © 2006 World Federation for Ultrasound in Medicine & Biology. |
URI: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-33646134593&doi=10.1016%2fj.ultrasmedbio.2006.01.010&partnerID=40&md5=663145e53c1dde140abfdbdc3cc462b7 https://scholars.lib.ntu.edu.tw/handle/123456789/481507 |
ISSN: | 03015629 | DOI: | 10.1016/j.ultrasmedbio.2006.01.010 | SDG/關鍵字: | Backscattering; Cavitation; Heat treatment; Hydrophones; Thermocouples; Transducers; Cavitation-enhanced heating; Low-frequency ultrasound; Ultrasound thermal therapy; Ultrasonic imaging; absorption; acoustics; animal tissue; article; controlled study; heating; high temperature; microbubble; muscle; needle; nonhuman; permeability; priority journal; swine; thermal exposure; thermal injury; transducer; ultrasound; ultrasound therapy; Acoustics; Animals; Feasibility Studies; Hyperthermia, Induced; Sonication; Swine; Temperature; Transducers; Ultrasonic Therapy |
顯示於: | 醫學系 |
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