Abstract #1809

Three-Slice MR Pre-Treatment Temperature Mapping and Spherical Model Estimation for Accurate Localization of the Heating Focus Before High-Intensity Focused Ultrasound Treatment

Hsu-Hsia Peng¹, Teng-Yi Huang², Hsiao-Wen Chung³, Po-Cheng Chen⁴, Yu-Hui Ding⁴, Shiun-Ying Ju², Yao-Hao Yang², Wen-Yih Isaac Tseng^5,6, Wen-Shiang Chen^4,7

¹Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan; ²Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan; ³Department of Electrical Engineering, National Taiwan University, Taipei, Taiwan; ⁴Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital, Taipei, Taiwan; ⁵Center for Optoelectronic Biomedicine, Medical College of National Taiwan University, Taipei, Taiwan; ⁶Department of Medical Imaging, National Taiwan University Hospital, Taipei, Taiwan; ⁷Division of Medical Engineering Research, National Health Research Institutes, Miaoli, Taiwan

During HIFU treatment, the focus of ultrasound (US) is arranged to the targeting region determined in advance. In practical treatments, however, the focus might be deviated due to the complex path (tissue-bone interface or tissue-air interface) of US beams. For safety considerations, accurate localization of heating focus is important before performing HIFU treatment. In this study, a spherical model is proposed to estimate the real position of US focus. A low power pre-treatment experiment was performed on ex vivo porcine muscle. The estimated focus position was verified via magnetization transfer ratio images after a high power HIFU transmission.