https://scholars.lib.ntu.edu.tw/handle/123456789/150273
標題: | 利用磁共振影像同步監測高能聚焦超音波治療時的溫度及磁轉移效應 Using Magnetic Resonance Imaging to Simultaneously onitor Temperature and Magnetization Transfer for High-Intensity Focused Ultrasound Treatment |
作者: | 彭旭霞 Peng, Hsu-Hsia |
關鍵字: | 溫度;磁轉移;熱治療;高能聚焦超音波;磁共振影像導引技術;組織傷害;temperature;magnetization transfer;thermal therapy;high-intensity focused ultrasound;MR guided;tissue damage | 公開日期: | 2009 | 摘要: | 利用磁共振影像去導引高能聚焦超音波的治療,不僅能夠增加治療時定位的準確性,更能在治療之後評估治療區域的範圍。我們的研究主要是希望能夠在超音波做治療時,同時量測溫度的變化以及磁轉移效應的改變。我們設計一個雙迴訊梯度脈衝序列,可以連續且插敘式地開關一個偏離共振頻率的脈衝,藉此得到與溫度相關的相位影像以及與組織燒灼程度有關的資訊。我們將設計的脈衝序列應用於含蛋白的假體、離體豬肉及豬肝的燒灼實驗。由所得到的結果顯示:從磁轉移比率所看到的燒灼區域大小與熱劑量所看到的區域大小很一致;即使物理性的溫度升高現象在加熱之後就逐漸消失,組織受加熱後所產生的生物性磁轉移效應改變仍會存留著。除此之外,熱劑量所看到的燒灼區域是很明確的,而磁轉移比率則可以顯示某個區域中不同程度的組織傷害。因此,當治療計畫中需要一個點接著一個點地連續治療某一個區域時,生物性磁轉移效應這項影像資訊,應該可以對於後續要治療的位置提供參考的影像。生物性磁轉移效應我們所提出的方法應該能夠改善高能聚焦超音波的治療效益,對於目標區域周圍的正常或重要的組織也能減少不必要的傷害。 Abstracthe utilization of MRI for guiding high-intensity focused ultrasound (HIFU) beams not only increases the localization accuracy during HIFU procedures but also allows evaluation of HIFU-induced lesions after treatment. Our study investigated the feasibility of estimating temperature changes and magnetization transfer (MT) contrast simultaneously during HIFU heating procedures, using a dual gradient-echo technique interleaved with ON and OFF off-resonant MT pulses. Egg white phantom studies and ex vivo experiments on the porcine liver and muscle tissues demonstrated that this method exhibited high consistence with thermal dose in respect of determining lesion size. Even though physical heat elevation disperses quickly after heating procedure, the biological change in MT ratio (MTR) due to tissue damage does not diminish. Moreover, thermal dose map derived from physical temperature elevation could sharply define the lesion size, whereas MTR map showed a distribution of biological effect of cell damage. The distribution of MTR, which was invisible in thermal dose map, might be helpful for efficiently arranging the locations and sonication conditions of subsequent heating spots, particularly in a spot-by-spot treatment planning. In conclusion, the proposed method could potentially improve HIFU heating efficiency and reduce unwanted heating damage to tissues nearby the targeting area.ey words: temperature, magnetization transfer, thermal therapy, high-intensity focused ultrasound, MR guided, tissue damage. |
URI: | http://ntur.lib.ntu.edu.tw//handle/246246/188011 |
顯示於: | 電機工程學系 |
檔案 | 描述 | 大小 | 格式 | |
---|---|---|---|---|
ntu-98-D93921028-1.pdf | 23.32 kB | Adobe PDF | 檢視/開啟 |
在 IR 系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。