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首頁> 外文學(xué)位 >A stationary digital breast tomosynthesis system: Design simulation, characterization and image reconstruction.
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A stationary digital breast tomosynthesis system: Design simulation, characterization and image reconstruction.

機(jī)譯：固定式數(shù)字乳房斷層合成系統(tǒng)：設(shè)計仿真，表征和圖像重建。

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摘要

Conventional screen-film and/or digital mammography, despite being the most popular breast imaging modalities, suffer from certain limitations, most important of which is tissue overlap and false diagnoses arising thereof. A new three-dimensional alternative for breast cancer screening and diagnosis is tomosynthesis in which a limited number of low-dose two-dimensional projection images of a patient are used to reconstruct the three-dimensional tissue information. The tomosynthesis systems currently under development all incorporate an x-ray source that moves over a certain angle to acquire images. This tube motion is a major limitation because it degrades image quality, increases the scan time and causes prolonged patient discomfort. The availability of independently controllable carbon nanotube cathodes enabled us to explore the possibility of setting up a stationary multi-beam imaging system. In this dissertation we have proposed a stationary digital breast tomosynthesis scanner using spatially distributed carbon nanotube based field emission x-ray sources. We have presented details about the design, set-up, characterization and image reconstruction of the completely stationary digital breast tomosynthesis system. This system has the potential to reduce the total scan time and improve the image quality in breast imaging.;Extensive design simulation results have been used to decide on the final system set-up. The fully assembled actual experimental system is capable of acquiring all the images in as little as eight seconds and yield superior image quality as well. The system has been completely characterized in terms of focal spot size, system resolution and geometric calibration. Certain important results have been obtained during the process that we hope will set the standard for the characterization of the future systems. A novel iterative reconstruction algorithm has been tried on the projection images obtained from the tomosynthesis system. Our algorithm has demonstrated image quality that is on par with the other tomosynthesis systems under development.
機(jī)譯：盡管是最流行的乳房成像方式，但是常規(guī)的屏幕膠片和/或數(shù)字乳腺X線攝影術(shù)仍具有一定的局限性，其中最重要的是組織重疊和由此引起的錯誤診斷。斷層合成是乳腺癌篩查和診斷的一種新的三維替代方法，其中有限數(shù)量的患者低劑量二維投影圖像用于重建三維組織信息。當(dāng)前正在開發(fā)的斷層合成系統(tǒng)都結(jié)合了X射線源，該X射線源以一定角度移動以獲取圖像。這種管運(yùn)動是一個主要限制，因為它會降低圖像質(zhì)量，增加掃描時間并導(dǎo)致患者長期不適?？瑟?dú)立控制的碳納米管陰極的可用性使我們能夠探索建立固定的多束成像系統(tǒng)的可能性。本文提出了一種基于空間分布的碳納米管場發(fā)射x射線源的固定式數(shù)字乳腺斷層掃描儀。我們已經(jīng)介紹了有關(guān)完全固定式數(shù)字乳房斷層合成系統(tǒng)的設(shè)計，設(shè)置，表征和圖像重建的詳細(xì)信息。該系統(tǒng)有可能減少總掃描時間并改善乳腺成像的圖像質(zhì)量。；廣泛的設(shè)計仿真結(jié)果已用于決定最終的系統(tǒng)設(shè)置。完全組裝的實(shí)際實(shí)驗系統(tǒng)能夠在短短八秒內(nèi)獲取所有圖像，并且還可以產(chǎn)生出色的圖像質(zhì)量。該系統(tǒng)已在焦斑大小，系統(tǒng)分辨率和幾何校準(zhǔn)方面得到了全面表征。在此過程中已經(jīng)獲得了某些重要的結(jié)果，我們希望將為未來系統(tǒng)的特性設(shè)定標(biāo)準(zhǔn)。已經(jīng)對從斷層合成系統(tǒng)獲得的投影圖像嘗試了一種新穎的迭代重建算法。我們的算法已經(jīng)證明了與正在開發(fā)的其他斷層合成系統(tǒng)相當(dāng)?shù)膱D像質(zhì)量。

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  • 作者

    Rajaram, Ramya.;

  • 作者單位

    The University of North Carolina at Chapel Hill.;

  • 授予單位 The University of North Carolina at Chapel Hill.;
  • 學(xué)科 Engineering Materials Science.
  • 學(xué)位 Ph.D.
  • 年度 2009
  • 頁碼 148 p.
  • 總頁數(shù) 148
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類 工程材料學(xué);
  • 關(guān)鍵詞

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