發(fā)布時(shí)間：2018-04-10 05:03

  本文選題：超聲　切入點(diǎn)：測溫成像　出處：《深圳大學(xué)》2017年碩士論文

【摘要】：傳統(tǒng)上,腫瘤的治療有放療、化療以及手術(shù)切除等方法。這些方法不僅療效不足,還對病人產(chǎn)生較大傷害。介入消融手術(shù)是一種新型的腫瘤治療方法,對病人的損傷更小、更安全、治療效率更高且能適應(yīng)更多癥狀,有非常好的應(yīng)用前景。為了更好的監(jiān)測介入消融手術(shù)的治療過程,無創(chuàng)的測溫成像技術(shù)十分關(guān)鍵。超聲無創(chuàng)測溫成像技術(shù)已經(jīng)有很多的研究,基于聲速變化的回波時(shí)移測溫法是一種有效的方法,但是它難以克服熱透鏡、熱膨脹以及病人運(yùn)動、呼吸帶來的干擾,因而在臨床上難以應(yīng)用。所以,本文提出一種可以克服這些問題的新方法。在介入消融手術(shù)中,治療區(qū)域的升溫會形成一個(gè)局部聲速區(qū)域,使得下方的成像會變模糊,根據(jù)這些現(xiàn)象,本論文提出一種應(yīng)用于介入消融治療手術(shù)監(jiān)控的,基于測量局部聲速空間分布的超聲無創(chuàng)測溫成像方法。本文通過前期基于靶點(diǎn)的超聲測溫實(shí)驗(yàn),驗(yàn)證了從一幀超聲通道數(shù)據(jù)中測量治療區(qū)聲速分布的可行性,從而克服既往超聲測溫算法中“熱膨脹”、“熱透鏡”以及病人運(yùn)動干擾的影響。為了更加接近臨床的情況,后續(xù)的進(jìn)一步研究中,用器官的成像輪廓代替靶點(diǎn)作為感興趣區(qū)域。實(shí)驗(yàn)中,將自制的不同聲速(1400-1800m/s)仿體與豬肝置于水槽中(水聲速約為1492m/s)以采集超聲通道數(shù)據(jù)。其中仿體模擬手術(shù)中的治療區(qū)域升溫,從而模擬臨床介入手術(shù)中的熱療情形。論文算法實(shí)現(xiàn)的步驟是:在Matlab平臺下,將超聲通道數(shù)據(jù)用合成孔徑方法重建出基線圖像后,自動搜索成像區(qū)域中的豬肝輪廓(如血管壁)作為感興趣區(qū)域,并且以聲速、橫坐標(biāo)、縱坐標(biāo)、半徑四個(gè)參數(shù)構(gòu)造出初始的局部聲速區(qū)域。然后,按照目前成像區(qū)域中的聲速分布,對感興趣區(qū)域進(jìn)行波束合成圖像重建,并量化評估其對焦質(zhì)量。迭代算法不斷調(diào)整迭代參數(shù)以優(yōu)化對焦質(zhì)量,這樣,構(gòu)造出來的局部聲速區(qū)域也會自適應(yīng)地逐漸逼近其真實(shí)情況,最終迭代出真實(shí)的聲速分布,并根據(jù)聲速與溫度之間的相關(guān)性進(jìn)行測溫成像。實(shí)驗(yàn)使用中國臺灣S-sharp公司的Prodig超聲科研平臺,采集128個(gè)收發(fā)通道的數(shù)據(jù),超聲探頭中心頻率為6MHz,采用頻率25MHz。算法成功地評估出局部聲速值及其分布,按本論文的誤差定義,局部聲速區(qū)域的位置評估誤差在1.52mm內(nèi),熱療程度的評估誤差在10%內(nèi)。所以,該方法很有潛力應(yīng)用于介入消融手術(shù)的無創(chuàng)測溫成像監(jiān)控中。
[Abstract]:Traditionally, cancer treatment includes radiotherapy, chemotherapy and surgical resection.These methods are not only ineffective, but also injurious to patients.Interventional ablation is a new method of tumor treatment, which has a better application prospect with less injury, more safety, higher therapeutic efficiency and more symptoms.In order to better monitor the procedure of interventional ablation, non-invasive thermography is very important.There have been many studies on ultrasonic noninvasive thermography. Echo time-shift thermometry based on the change of sound velocity is an effective method, but it is difficult to overcome the interference of thermal lens, thermal expansion and patient's movement and breathing.Therefore, it is difficult to apply in clinic.Therefore, this paper proposes a new method to overcome these problems.During the interventional ablation, the temperature of the treatment area will form a local sound velocity area, which will make the imaging of the lower part blurred. According to these phenomena, this paper proposes a new method for monitoring the operation of interventional ablation.Ultrasonic non-invasive temperature imaging method based on measuring the spatial distribution of local sound velocity.In this paper, the feasibility of measuring the distribution of sound velocity in the treatment area from a frame of ultrasonic channel data is verified by the previous target based ultrasonic temperature measurement experiment, which overcomes the "thermal expansion" in the previous ultrasonic temperature measurement algorithm.Thermal lenses and the effects of patient motion interference.In order to get closer to the clinical situation, the imaging contour of the organ is used to replace the target as the region of interest in the further research.In the experiment, the self-made imitation of different sound velocities (1400-1800 m / s) and the porcine liver were placed in the water tank (about 1492 m / s) to collect the ultrasonic channel data.The temperature of the treatment area in simulated surgery is simulated, thus the hyperthermia in interventional surgery is simulated.The steps of the algorithm are as follows: after the ultrasonic channel data is reconstructed by synthetic aperture method on the Matlab platform, the pig liver contour (such as vascular wall) in the imaging region is automatically searched as the region of interest, and the sound velocity is used.The initial local velocity region is constructed by four parameters, namely, the transverse coordinate, the vertical coordinate and the radius.Then, the beam-synthesizing image of the region of interest is reconstructed according to the sound velocity distribution in the current imaging region, and its focus quality is evaluated quantitatively.The iterative algorithm constantly adjusts the iterative parameters to optimize the focusing mass, so that the constructed local sound velocity region will gradually approach its real situation adaptively, and finally iterate out the true sound velocity distribution.According to the correlation between sound velocity and temperature, temperature imaging was carried out.The data of 128 transceiver channels were collected by using the Prodig ultrasonic research platform of Taiwan S-sharp Company. The center frequency of ultrasonic probe was 6 MHz and the frequency of ultrasonic probe was 25 MHz.The local sound velocity and its distribution are evaluated successfully. According to the definition of error in this paper, the error of local sound velocity region is in 1.52mm, and the error of hyperthermia is less than 10%.Therefore, this method has the potential to be used in non-invasive thermography monitoring of interventional ablation surgery.
【學(xué)位授予單位】：深圳大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：R730.5;TB559

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