Real-time visualization of high-intensity focused ultrasound treatment using ultrasound imaging.
High-intensity focused ultrasound (HIFU) and conventional B-mode ultrasound (US) imaging were synchronized to develop a system for real-time visualization of HIFU treatment. The system was tested in vivo in pig liver. The HIFU application resulted in the appearance of a hyperechoic spot at the focus that faded gradually after cessation of HIFU exposure. The duration of HIFU exposure needed for a hyperechoic spot to appear, was inversely related to the HIFU intensity. The threshold intensity required to produce a hyperechoic spot in liver in < 1 s was 970 W/cm(2), in situ. At this HIFU dose, no immediate cellular damage was observed, providing a potential for pretreatment targeting. The real-time visualization method was used in hemostasis of actively bleeding internal pelvic vessels, allowing targeting and monitoring of successful treatment. Real-time US imaging may provide a useful tool for image-guided HIFU therapy.
Vaezy
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S
Department of Bioengineering, University of Washington, Seattle, WA 98195, USA. adasi@u.washington.edu
Shi
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Martin
R W
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Chi
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Nelson
P I
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Bailey
M R
MR
Crum
L A
LA
D000818:Animals; D004867:Equipment Design; D008099:Liver / Q000000981:diagnostic imaging; D013552:Swine; D014464:Ultrasonic Therapy; D014463:Ultrasonography / Q000379:methods*