發(fā)布時(shí)間：2018-10-12 07:57

【摘要】：正電子發(fā)射斷層成像（Positron Emission Tomography，簡稱PET）是一種非侵入式的造影方法，它通過探測活體內(nèi)攝入放射性示蹤劑的分布，無創(chuàng)、定動(dòng)態(tài)地評(píng)估生物體內(nèi)各種器官的代謝水平、生化反應(yīng)、功能活動(dòng)和灌注。作為當(dāng)今核醫(yī)學(xué)診斷和研究的尖端技術(shù)，PET在腫瘤、心血管、神經(jīng)系統(tǒng)等的早期診斷、療效評(píng)估以及基礎(chǔ)研究等領(lǐng)域有著獨(dú)特的應(yīng)用價(jià)值。數(shù)字化的PET數(shù)據(jù)獲得系統(tǒng)能夠有效解決傳統(tǒng)PET系統(tǒng)容易受環(huán)境干擾，校正困難的問題，同時(shí)引入數(shù)字信號(hào)處理技術(shù)帶來的多種優(yōu)勢，是目前PET儀器設(shè)計(jì)的熱點(diǎn)方向。 本文對一種新的全數(shù)字化脈沖獲取能量獲取方法——多電壓閾值采樣法(簡稱MVT)獲取能量的關(guān)鍵因素進(jìn)行了研究，包括噪聲，基線，時(shí)間數(shù)字轉(zhuǎn)換器（簡稱TDC）精度，以及閾值設(shè)置。提出了基于MVT的下降沿噪聲處理方法，準(zhǔn)確的獲取脈沖的能量信息。并模擬仿真了實(shí)際硬件閾值個(gè)數(shù)與時(shí)間數(shù)字轉(zhuǎn)換器的精度對MVT能量獲取的影響。實(shí)現(xiàn)了基于MVT的基線校正算法。為實(shí)現(xiàn)MVT方法的PET采集系統(tǒng)奠定了基礎(chǔ)。 在仿真的基礎(chǔ)上，本文實(shí)現(xiàn)了一個(gè)基于MVT方法的閃爍能量脈沖獲取系統(tǒng)，，該系統(tǒng)具有死時(shí)間短，全數(shù)字化，易于后期校正等優(yōu)勢。并以該系統(tǒng)為基礎(chǔ)，對之前的仿真方法進(jìn)行了驗(yàn)證，取得了初步的結(jié)果，為PET系統(tǒng)的全數(shù)字化能量獲取打下了基礎(chǔ)。 最后，本文以華中科技大學(xué)研制的數(shù)字化小動(dòng)物PET系統(tǒng)為基礎(chǔ)，充分運(yùn)用閃爍脈沖特性和數(shù)字信號(hào)處理技術(shù)，研究并實(shí)現(xiàn)了閃爍脈沖的能量信息獲取單元。在結(jié)合實(shí)際性能因素的考慮下，利用數(shù)字積分方法，獲得了良好的能量性能，達(dá)到了預(yù)期的要求。
[Abstract]:Positron Emission Tomography (Positron Emission Tomography,) is a non-invasive imaging method that dynamically evaluates the metabolic level and biochemical reactions of various organs in living organisms by detecting the distribution of radioactive tracers in vivo. Functional activity and perfusion. As a cutting-edge technology in nuclear medicine diagnosis and research, PET has unique application value in early diagnosis, evaluation of curative effect and basic research in tumor, cardiovascular, nervous system and so on. The digital PET data acquisition system can effectively solve the problem that traditional PET system is vulnerable to environmental interference and difficult to correct. At the same time, the introduction of digital signal processing technology brings a variety of advantages, which is a hot spot in the design of PET instruments. In this paper, a new all-digital pulse acquisition method, multi-voltage threshold sampling (MVT), is studied, which includes the accuracy of noise, baseline and time-digital converter (TDC). And threshold setting. A method of noise processing based on MVT is proposed to obtain the energy information of pulse accurately. The effect of the actual hardware threshold number and the precision of the time digital converter on the MVT energy acquisition is simulated and simulated. The baseline correction algorithm based on MVT is implemented. It lays a foundation for the realization of PET acquisition system of MVT method. On the basis of simulation, a flash energy pulse acquisition system based on MVT method is implemented in this paper. The system has the advantages of short dead time, full digitization and easy post-correction. Based on this system, the previous simulation method is verified, and the preliminary results are obtained, which lays the foundation for the full digital energy acquisition of PET system. Finally, based on the digital small animal PET system developed by Huazhong University of Science and Technology, the energy information acquisition unit of scintillation pulse is studied and realized by making full use of the characteristics of scintillation pulse and digital signal processing technology. Under the consideration of the actual performance factors, the digital integral method is used to obtain good energy performance and meet the expected requirements.
【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2013
【分類號(hào)】：R310

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 劉士濤,許咨宗,曾海寧,李輝;PSPMT基本特性的實(shí)驗(yàn)研究[J];核技術(shù);2000年08期

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