本文選題：高頻超聲 + 血流成像�。� 參考：《北京協(xié)和醫(yī)學(xué)院》2015年碩士論文

【摘要】：醫(yī)學(xué)超聲成像技術(shù)以其無創(chuàng)、安全、實(shí)時成像等優(yōu)點(diǎn)應(yīng)用廣泛。超聲血流成像是超聲診斷的重要分支,可以準(zhǔn)確直觀地反映組織內(nèi)部的供血狀況,為臨床診斷提供多方位信息；其中灰階血流成像技術(shù)以其高分辨力、無角度依賴等特點(diǎn)具有重要的研究價(jià)值。本文提出了一種新的灰階血流成像方法,旨在實(shí)現(xiàn)高頻條件下血流圖像的獲取,克服傳統(tǒng)技術(shù)的操作復(fù)雜、參數(shù)依賴、高頻不適用等缺點(diǎn),并建立理論支撐體系作為高頻血流成像領(lǐng)域的重要補(bǔ)充。首先根據(jù)血液中的主要散射體即紅細(xì)胞的特征,分析其背向散射特性,綜合超聲衰減因素并建立散射模型,從而確定在高頻條件下淺表部位血流成像的可行性和成像的頻率范圍；然后由理論推導(dǎo)設(shè)計(jì)了算法和實(shí)現(xiàn)方式,根據(jù)組織和血流信息的差異性來獲取血流信息,從而將較弱的血液回聲和較強(qiáng)的組織回聲區(qū)分開來,實(shí)現(xiàn)灰階血流成像。論文基于可編程邏輯器件完成了實(shí)驗(yàn)平臺的設(shè)計(jì),用不同頻率的探頭驗(yàn)證理論模型的正確性；并使用20MHz超聲掃描探頭、使用模擬血液、模擬血管得到血流圖像,成像結(jié)果與實(shí)際相符,且該方法對于0.3mm的血管內(nèi)血流分辨清晰；本文進(jìn)一步研究圖像的亮度值與血液流速的關(guān)系：流速7.4cm/s至44.5cm/s線性度較好,在51.9cm/s時亮度達(dá)到最大值,并論證不同的掃描方式對成像結(jié)果的影響；最后運(yùn)用該方法對人手背部靜脈成像,可以得到血管內(nèi)清晰的超聲血流圖。該方法在高頻超聲成像時無需采用傳統(tǒng)的脈沖編碼方式,僅單脈沖掃描即可獲取微弱的血流信息,同時具有與結(jié)構(gòu)成像相同的高分辨力,為淺表器官的疾病診斷提供了可靠依據(jù),具有較好的實(shí)際應(yīng)用價(jià)值。
[Abstract]:Medical ultrasound imaging technology is widely used because of its advantages of non-invasive, safety and real-time imaging. Ultrasound blood flow imaging is an important branch of ultrasonic diagnosis, which can accurately and intuitively reflect the blood supply status in tissues and provide multi-directional information for clinical diagnosis. The characteristics of angle-free dependence have important research value. In this paper, a new gray-scale blood flow imaging method is proposed, which aims to obtain blood flow images at high frequency, and overcome the disadvantages of complex operation, parameter dependence and inapplicability of high frequency. The theoretical support system is established as an important supplement in the field of high frequency blood flow imaging. Firstly, according to the characteristics of the main scatterer in blood, red blood cell (RBC), the backscattering characteristics are analyzed, and the ultrasonic attenuation factors are synthesised and the scattering model is established. In order to determine the feasibility of superficial blood flow imaging and the frequency range of imaging under the high frequency condition, then the algorithm and implementation method are designed by theoretical derivation, and the blood flow information is obtained according to the difference of tissue and blood flow information. In order to distinguish the weak blood echo from the strong tissue echo, the gray-scale blood flow imaging can be realized. The experiment platform is designed based on programmable logic device, and the theoretical model is verified by different frequency probe, and the blood flow image is obtained by using 20MHz ultrasonic scanning probe and simulated blood vessel. The imaging results are consistent with the actual results, and the resolution of intravascular blood flow in 0.3mm is clear. In this paper, the relationship between image brightness and blood flow velocity is further studied: the linearity between 7.4cm/s velocity and 44.5cm/s velocity is good, and the brightness reaches the maximum value at 51.9cm/s. The effects of different scanning methods on the imaging results were demonstrated. This method can obtain weak blood flow information only by single pulse scanning without using the traditional pulse coding method in high frequency ultrasonic imaging, and it has the same high resolution as structural imaging. It provides a reliable basis for the diagnosis of superficial organ diseases and has good practical application value.
【學(xué)位授予單位】：北京協(xié)和醫(yī)學(xué)院
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：R445.1

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相關(guān)期刊論文 前2條

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本文編號：1919401