碩士 / 長庚大學 / 醫學影像暨放射科學系 / 106 / High-intensity focused ultrasound (HIFU) is a non-invasive application, so that it is suitable for thermal therapy. However, it is hard to localize the heating point of HIFU. Using medical images to localize heating point is a necessary process before treatment. The changes in backscattered energy (CBE) in ultrasound is an easy way to get the temperature distribution of tissue. But the low contrast of CBE images makes it hard to localize the exact heating point.
In this study, we built up frequency-domain CBE image and interference image to improve the obstacle of traditional CBE image. In phantom experiment, the radiofrequency data and temperature information are collected. And run different algorithms to get the contrast and temperature-performance. Compare these data to find out the advantages and disadvantage of these algorithms.
In image contrast, interference image shows significantly higher than traditional CBE image. Under lower power of HIFU, frequency-domain CBE image is also higher than traditional one. And CBE images are highly relative to temperature, especially the traditional CBE image.
In summary, each algorithm is suitable for different situations. According to the requirements and conditions, suitable algorithm can be selected to obtain the better image.
| Identifer | oai:union.ndltd.org:TW/106CGU05770001 |
| Date | January 2018 |
| Creators | Cheng Wei Huang, 黃振維 |
| Contributors | P. H. Tsui, 崔博翔 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 110 |
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