Image–Guided Ex vivo Liver Ablation by Unfocused Ultrasound using Passive Cavitation Detection

Vasant A. Salgaonkar; Chandra Priya Karunakaran; John A. Besse; Grace Heinlein; Saurabh Datta; Christy K. Holland; T. Douglas Mast

doi:10.1117/12.701029

10 March 2007 Image-guided ex vivo liver ablation by unfocused ultrasound using passive cavitation detection

Vasant A. Salgaonkar, Chandra Priya Karunakaran, John A. Besse, Grace Heinlein, Saurabh Datta, Christy K. Holland, T. Douglas Mast

Author Affiliations +

Proceedings Volume 6440, Thermal Treatment of Tissue: Energy Delivery and Assessment IV; 64400Q (2007) https://doi.org/10.1117/12.701029
Event: SPIE BiOS, 2007, San Jose, California, United States

Abstract

Ablation therapy is used as an alternative to surgical resection of hepatic tumors. In ablation, tumors are destroyed through heating by RF current, high intensity focused ultrasound (HIFU), or other energy sources. Ablation can be performed with a linear array transducer delivering unfocused intense ultrasound (<10 W/cm²). This allows simultaneous treatment and imaging, a feature uncommon in RF ablation. Unfocused ultrasound can also enable faster bulk tissue ablation than HIFU. In the experiments reported here, a 32-element linear array transducer with a 49 mm aperture delivers 3.1 MHz continuous wave unfocused ultrasound at amplitudes 0.7-1.4 MPa during the therapy cycle. It also operates in pulse-echo mode to capture B-scan images. Ex-vivo fresh bovine liver tissue placed in degassed saline is exposed to continuous wave ultrasound interleaved with brief pulsed ultrasound imaging cycles. Tissue exposures range between 5 to 20 minutes. The following measurements are made at intervals of 1 to 3 seconds: tissue temperature with a needle thermocouple, acoustic emissions with a 1 MHz passive unfocused detector, and tissue echogenicity from image brightness. Passively detected acoustic emissions are used to quantify cavitation activity in the ablation experiments presented here. As severity and extent of tissue ablation are related to temperature, this paper will statistically model temperature as a function of tissue echogenicity and cavitation. The latter two quantities can potentially be monitored noninvasively and used as a surrogate for temperature, enabling improved image guidance and control of ultrasound ablation.

Citation Download Citation

Vasant A. Salgaonkar, Chandra Priya Karunakaran, John A. Besse, Grace Heinlein, Saurabh Datta, Christy K. Holland, and T. Douglas Mast "Image-guided ex vivo liver ablation by unfocused ultrasound using passive cavitation detection", Proc. SPIE 6440, Thermal Treatment of Tissue: Energy Delivery and Assessment IV, 64400Q (10 March 2007); https://doi.org/10.1117/12.701029

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available