Imaging of Thermally Ablated Tissue Using Ultrasonic Elastography

• Published in: Key engineering materials 2004-01, Vol.270-273, p.2042-2047
• Main Authors: Ahn, Young Bok, Jeong, Mok Kun, Choi, Min Joo, Kwon, Sung Jae
• Format: Article
• Language: English
• ISSN: 1013-9826; 1662-9795; 1662-9795
• DOI: 10.4028/www.scientific.net/KEM.270-273.2042

High intensity focused ultrasound (HIFU) is a promising noninvasive technique that thermally ablates tumors lying deep in the tissue, but the extent of thermal necrosis is difficult to quantify with current B-mode imaging techniques. Utilizing the fact that necrotic tissue is stiffer than normal tissue, we propose a new ultrasound elastographic imaging method to assess the progress of HIFU treatment. The method applies a mechanical compression to tissue being examined by pushing with a transducer, acquires its B-mode images freehand, and computes the phase difference between pre- and postcompression complex baseband echoes as an indicator of tissue stiffness. Being able to detect small displacements, the proposed method is implemented in real time in a commercial diagnostic ultrasonic scanner. It is capable of producing strain images at a rate of up to 24 frames/s. The experimental results show that the method is a viable technique to monitor the change in stiffness of tissue under treatment with HIFU.