近年來非侵入式治療已受到相當的重視，其中高能聚焦式超音波(high intensity focused ultrasound，HIFU)所引發之局部熱燒灼治療是輔助性外科切除患部相當有潛力的新工具。但臨床醫生僅藉由傳統超音波B-mode影像不易判斷出加熱區域及加熱程度而增添醫療過程的危險性。在本研究中我們提出利用一種新式的超音波造影模式- Nakagami超音波參數造影 - 來即時偵測及監控高能聚焦式超音波熱燒灼區域。Nakagami超音波參數造影已被證實具有利用組織中的局部散射子在分佈、排列、濃度上的差異進行組織特徵化的能力，而我們推測當組織被加熱時，散射子的分佈、排列、濃度會隨著受熱而發生改變，而導致Nakagami參數發生變化，因此具有潛力對熱燒灼區域進行即時性偵測。實驗中藉由1.5MHz高能聚焦式超音波換能器對於離體組織進行熱燒灼，並以超音波成像系統擷取RF data，再透過Nakagami成像原理之演算法分析envelope data來形成Nakagami參數影像。本研究中也將Nakagami與其他3種參數MSS、IBS、RMS作比較。實驗結果顯示在無明顯氣泡產生的情況下，B-mode影像不易觀察燒灼區域，但透過Nakagami超音波參數造影，仍可在加熱過程中觀察到熱燒灼區域之位置，並且其燒灼前後參數影像間的對比較傳統B-mode影像來得好。至於在有明顯氣泡產生的情況下，其燒灼前後參數影像中找出的燒灼區域位置和大小與真實燒灼區域相當。另外，Nakagami超音波參數造影是在envelope data上作計算，故運算量相對很低，可以達到即時監控的目的。相較之下，利用其他MSS、IBS、RMS參數則無法正確得知燒灼位置及大小。未來工作將進一步利用Nakagami參數影像和超音波溫度、彈性影像比較甚至結合進行多參數影像來監控高能聚焦式超音波的熱燒灼，並延伸應用於高能聚焦式超音波產生熱燒灼機制的分類。

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