DC 欄位 | 值 | 語言 |
dc.contributor | 鍾孝文 | zh-TW |
dc.contributor | Chung, Hsiao-Wen | en |
dc.contributor | 臺灣大學:電機工程學研究所 | zh-TW |
dc.contributor.author | 彭旭霞 | zh-TW |
dc.contributor.author | Peng, Hsu-Hsia | en |
dc.creator | 彭旭霞 | zh-TW |
dc.creator | Peng, Hsu-Hsia | en |
dc.date | 2009 | en |
dc.date.accessioned | 2010-07-01T02:29:34Z | - |
dc.date.accessioned | 2018-07-06T11:49:12Z | - |
dc.date.available | 2010-07-01T02:29:34Z | - |
dc.date.available | 2018-07-06T11:49:12Z | - |
dc.date.issued | 2009 | - |
dc.identifier.other | U0001-0701200916505900 | en |
dc.identifier.uri | http://ntur.lib.ntu.edu.tw//handle/246246/188011 | - |
dc.description.abstract | 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。 | zh-TW |
dc.description.abstract | 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. | en |
dc.description.tableofcontents | Contents試委員審定書 II文致謝 III文摘要 Vbstract VIist of Figures IXist of Tables XIhapter 1 Introduction 1.1 Thermal Therapy and MR Guided HIFU 1.1.1 Thermal Therapy 1.1.2 MR guided HIFU 1.2 Current Methods of Monitoring Heating Efficiency 2.3 Motivation 4.4 Organization 5hapter 2 Theory 6.1 Measure Temperature by MRI: Proton Resonance Frequency Shift 6.1.1 MR Phase Image and Chemical Shift due to Temperature Change 6.1.2 Measure Temperature Change by Proton Resonance Frequency Shift 11.1.3 Thermal Dose Calculation 13.2 Magnetization Transfer Effect and Magnetization Transfer Ratio 14.2.1 Magnetization Transfer (MT) effect 14.2.2 Magnetization Transfer Ratio (MTR) 17hapter 3 Simultaneous Monitoring of Temperature and Magnetization Transfer 18.1 The Designed Pulse Sequence 18.2 Validation Experiments 20.2.1 Validation of Temperature Measurements 20.2.2 Sweep Frequency 24.3 Heating Experiments Set-up 28hapter 4 Experiments 31.1 Phantom Experiments 31.1.1 Experiment Set-up 32.1.2 Results 34.1.3 Quantitative Analysis 37.2 Ex Vivo Experiments on Porcine Liver 39.2.1 Experiment Set-up 39.2.2 Results 41.2.3 Quantitative Analysis 48.3 Ex Vivo Experiments on Porcine Muscle 50.3.1 Experiment Set-up 50.3.2 Results 51.3.3 Quantitative Analysis 53.4 Two Heating Spots on Phantom 56.5 MTR Values in Phantoms With Different Concentration of Egg White 59.6 Pre-treatment Experiments: To Find Out the Position of Heating Focus 63.7 Over Heating Experiment 69hapter 5 Discussion 75.1 Comparison With Other Methods for Quantifying Tissue Damage 76.2 Comparison of Spot Size Determined by Temperature, MTR and Thermal Dose 77.3 The Characteristics of MT effect in Different Tissues 81.4 Limitations 82.4.1 Slice Number and Temporal Resolution 82.4.2 Temperature Measurement 83.4.3 MTR Measurements 84.5 Future Work 85.6 Conclusions 85eferences……..….……..……..….…..…..…..…..…..…..…...….......……….... 87ist of Figuresig. 1.1. The lattice-like treatment planning 3ig. 2.1. The definition of phase 7ig. 2.2. A schematic diagram of chemical shift effect 9ig. 2.3. The flow chart relates temperature change to proton resonant frequency shift and phase 10ig. 2.4. The illustration of two pools model and magnetization transfer effect 16ig. 3.1. The developed pulse sequence. The dual gradient-echo sequence interleaved with and without off-resonance MT pulses, respectively 19ig. 3.2. The apparatus for verifying the accuracy of temperature change measured by PFR shift method 21ig. 3.3. The phase images of a tub of hot water within 634 sec 22ig. 3.4. The maps of measured temperature decrease 23ig. 3.5. The values of temperature decrease of hot water were measured by MR PRF shift and thermal meter 23ig. 3.6. The magnitude images with different offset frequencies of RF irradiation 25ig. 3.7. The values of signal intensity and CNR as a function of offset frequency at heated-spot and non-heated area of phantom 27ig. 3.8. The schematic heating apparatus 28ig. 3.9. The experimental set-up of targeting tissue and HIFU transducer 29ig. 4.1. The schematic heating process and the time course of MR acquisition for experiment of 60% egg white phantom 33ig. 4.2. The phase images and the calculated pseudo-colored temperature change maps 35ig. 4.3. Comparison of optical picture of cut face of the heated egg white phantom, MTR map, ΔMTR map 2 min after turning off of HIFU heating pulses, and the thermal dose map 37ig. 4.4. The time course of temperature change and MTR 38ig. 4.5. The schematic heating process and the time course of MR acquisition for ex vivo experiment of porcine liver 40ig. 4.7. The phase images and the calculated pseudo-colored temperature change maps 42ig. 4.8. The magnitude images with MT pulses and without MT pulses 44ig. 4.9. The estimated MTR maps of the whole time course 45ig. 4.10 Pseudo-colored maps of temperature change, MTR, filtered ΔMTR and thermal dose (TD) maps 47ig. 4.11. The time course of temperature change and MTR 49ig. 4.12. The schematic heating process and the time course of MR acquisition or ex vivo experiment of porcine muscle 51ig. 4.13. Comparison of optical picture, MTR, ΔMTR and thermal dose maps at the end of whole heating procedure 52ig. 4.14. The time course of temperature change and MTR 55ig. 4.15. The schematic heating process and the time course of MR acquisition or two heating spots of phantom 57ig. 4.16. The results of the heating spot and the previous heated spot 58ig. 4.17. The MTR valuse of phantoms with different egg white concentration 60ig. 4.18. The schematic heating process and the time course of MR acquisition or pre-treatment experiments 65ig. 4.19. The results of pre-heat experiments 67ig. 4.20. The results of over-heating experiments 72ig. 4.21. The time course of over-heating experiment 73ig. 5.1. Compare the heated spot size of porcine liver evaluated by temperature ise and MTR to that determined by thermal dose 79 ist of Tablesable 2.1. Temperature dependence coefficient α of different materials 12able 2.2. The phase change of different temperature elevation and echo time 13able 3.1. MR parameters for validation of temperature measurement. 21able 3.2. The materials included in phantom for experiment of sweep frequency 24able 4.1. The materials included in the 60% egg white phantom 33able 4.2. The MR parameters for experiment of 60% egg white phantom 33able 4.3. The MR parameters for ex vivo experiment of porcine liver 40able 4.4. The MR parameters for ex vivo experiment of porcine muscle 51able 4.5. The MR parameters for two heating spots of phantom 57able 4.6 The values of MTRin the phantoms with different concentration of egg hite 62able 4.7. The MR parameters for pre-treatment experiments …66 | en |
dc.format.extent | 5574989 bytes | - |
dc.format.mimetype | application/pdf | - |
dc.language | en | en |
dc.language.iso | en_US | - |
dc.subject | 溫度 | zh-TW |
dc.subject | 磁轉移 | zh-TW |
dc.subject | 熱治療 | zh-TW |
dc.subject | 高能聚焦超音波 | zh-TW |
dc.subject | 磁共振影像導引技術 | zh-TW |
dc.subject | 組織傷害 | zh-TW |
dc.subject | temperature | en |
dc.subject | magnetization transfer | en |
dc.subject | thermal therapy | en |
dc.subject | high-intensity focused ultrasound | en |
dc.subject | MR guided | en |
dc.subject | tissue damage | en |
dc.title | 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 | zh-TW |
dc.title | Using Magnetic Resonance Imaging to Simultaneously onitor Temperature and Magnetization Transfer for High-Intensity Focused Ultrasound Treatment | en |
dc.type | thesis | en |
dc.identifier.uri.fulltext | http://ntur.lib.ntu.edu.tw/bitstream/246246/188011/1/ntu-98-D93921028-1.pdf | - |
item.fulltext | with fulltext | - |
item.cerifentitytype | Publications | - |
item.languageiso639-1 | en_US | - |
item.openairetype | thesis | - |
item.openairecristype | http://purl.org/coar/resource_type/c_46ec | - |
item.grantfulltext | open | - |
顯示於: | 電機工程學系
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