用於電漿光熱治療之熱應變光聲溫度造影技術

在以金奈米粒子為輔之電漿光熱治療中，基於光聲造影之溫度估測技術與現有的技術相較之下有著高對比度、非侵入式、二維造影、以及不易受到低回波組織影響等優勢。本論文開發一套光聲溫度造影技術-基於熱應變之光聲溫度造影技術，相較於現有的基於訊號強度之光聲溫度造影技術而言，該光聲溫度造影技術能夠克服現有技術受限於脈衝雷射能量不穩定的缺點以及用於電漿光熱治療的金奈米粒子熱穩定性不足之限制。首先利用電腦模擬模仿局部加溫情況下的光聲訊號以及光吸收物分佈狀況等因素對上述兩種光聲溫度估測的可行性以及影響，而後根據在溫度變化下的A-line光聲訊號實驗之訊號強度及其熱應變跟實際溫度的關係作為訊號強度與熱應變資訊換算成溫度時的依據，並討論適合用於互相關分析的參數，最後利用光聲陣列造影實驗架構配合連續波雷射系統在金奈米桿仿體上進行電漿光熱治療實驗以驗證上述兩種光聲溫度造影的可行性並分析其差異，藉此說明基於熱應變之光聲溫度造影技術在10℃溫度變化範圍內可達到0.17℃的溫度解析度，相較於另一者是更為穩定、精確、適合發展於臨床電漿光熱治療的溫度造影技術。

關鍵字

光聲；光熱治療；金奈米桿；熱應變；溫度影像

並列摘要

Photoacoustic (PA) temperature estimation for gold nanoparticles based plasmonic photothermal therapy (PPTT) has advantages, such as high intrinsic contrast, non-invasive, two-dimension imaging, and insusceptible for hypoechoic tissue that are unavailable in current temperature measurement technologies. In this thesis, we developed a thermal strain based PA temperature imaging technique based on cross-correlation algorithm. Unlike the existing amplitude based PA temperature estimation, the thermal strain based PA temperature estimation is unaffected by problems such as fluctuation of pulse laser energy and lack of photothermal stability of gold nanoparticles for PPTT. First, we proved the feasibility of thermal strain based PA temperature imaging using computer simulations, and then we confirmed the effects of varying distributions of optical absorbers. Next we built temperature calibration tables of amplitude and thermal strain based PA estimation using data obtained in PA A-line experiments. According to the above-mentioned data, we optimized the parameters of cross-correlation analysis. In phantom experiments of plasmonic photothermal therapy, we verified the feasibility and performance of amplitude and thermal strain based PA temperature imaging on a photoacoustic array imaging system. The experimental result of thermal strain based PA temperature imaging indicated a temperature resolution of 0.17℃ for 10℃ temperature-changes. To sum up, the thermal strain based PA temperature estimation is a more stable and accurate temperature monitoring technique for plasmonic photothermal therapy than the amplitude based PA temperature estimation.

並列關鍵字

photoacoustic ； photothermal therapy ； AuNRs ； thermal strain ； temperature imaging

參考文獻

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國際替代計量

用於電漿光熱治療之熱應變光聲溫度造影技術

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