本文選題：高強度聚焦超聲 + B超圖像��； 參考：《湖南師范大學(xué)》2008年碩士論文

【摘要】： 高強度聚焦超聲(HIFU)作為一種新的癌癥治療手段越來越受到人們的重視。因為它是基于高溫?zé)嵝?yīng)對組織損傷的原理,所以對治療過程中組織損傷的評價和組織溫度的測量都十分重要。傳統(tǒng)損傷評價的方法是醫(yī)生憑借長期的經(jīng)驗積累判定組織是否凝固壞死,這種方法的缺點是很容易引起誤判;而傳統(tǒng)的有損測溫的方法會給病人帶來痛苦且容易引起腫瘤轉(zhuǎn)移,因此其應(yīng)用受到很大限制。 本文詳細(xì)研究了超聲治療過程中的組織損傷評價和無損測溫問題,對生物組織在高強度聚焦超聲加熱時組織的B超圖像隨溫度變化的關(guān)系進(jìn)行了研究分析,所做的主要工作有: 1在邊緣檢測和邊緣增強方面做了大量研究,提出了一種有效的B超圖像邊緣檢測方法,使用該方法可以自動確定HIFU輻照焦點區(qū)域邊緣。 2通過大量實驗數(shù)據(jù)分析了B超圖像的灰度特征與組織溫度的關(guān)系。研究發(fā)現(xiàn),當(dāng)組織初始溫度為37～40℃且溫升在30℃以內(nèi)時,焦域內(nèi)的灰度平均值與溫度變化值基本呈線性關(guān)系,且多次實驗結(jié)果的收斂性較好;當(dāng)溫升大于30℃時,多次實驗結(jié)果的收斂性降低。 3分析了B超圖像的灰度特征和分形特征值與組織損傷程度的關(guān)系。結(jié)果表明:利用B超圖像焦域位置的灰度平均值和分形截距判斷組織是否發(fā)生蛋白質(zhì)凝固的準(zhǔn)確度分別可達(dá)89%和93%以上。 4利用頻域分析方法,通過對B超圖像焦域位置進(jìn)行離散余弦變化,將結(jié)果的低頻矢量輸入神經(jīng)網(wǎng)絡(luò),利用神經(jīng)網(wǎng)絡(luò)的模式分類功能對實驗樣本的損傷程度進(jìn)行自動識別,結(jié)果表明該方法能準(zhǔn)確判定組織蛋白質(zhì)是否凝固。 本文做了大量實驗研究,通過對這些數(shù)據(jù)樣本分析建立了組織損傷評價的規(guī)則和B超無損測溫的方法。雖然要實現(xiàn)精確測溫還比較困難,但這些方法均能較準(zhǔn)確地反映出組織的損傷程度和溫升趨勢。本文所做工作對HIFU治療有重要意義,其結(jié)果具有一定的參考價值。
[Abstract]:High intensity focused ultrasound (HIFU) has been paid more and more attention as a new method of cancer treatment. Because it is based on the principle of tissue damage caused by hyperthermia, it is very important to evaluate the tissue injury and measure the tissue temperature in the course of treatment. The traditional method of damage assessment is based on the doctor's long-term experience to determine whether the tissue coagulated and necrotic. The disadvantage of this method is that it can easily lead to misjudgment, while the traditional method of damaging temperature measurement can bring pain to the patient and cause tumor metastasis. Therefore, its application is greatly restricted. In this paper, the tissue damage evaluation and nondestructive temperature measurement during ultrasound treatment are studied in detail. The relationship between the B ultrasonic images of biological tissue and temperature during high intensity focused ultrasound heating is analyzed. The main works are as follows: (1) We have done a lot of research on edge detection and edge enhancement, and put forward an effective edge detection method for B-ultrasound image. Using this method, the edge of HIFU irradiating focal area can be automatically determined. 2 the relationship between gray characteristics and tissue temperature of B-ultrasound image is analyzed by a large number of experimental data. It is found that when the initial temperature of the tissue is 37 ~ 40 鈩，

本文編號：2114396