首页> 美国卫生研究院文献>Medical Physics >Noise sampling and the number of projections in cone-beam CT with a flat-panel detector
【2h】

Noise sampling and the number of projections in cone-beam CT with a flat-panel detector

机译:平板探测器在锥形束CT中的噪声采样和投影数量

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

>Purpose: To investigate the effect of the number of projection views on image noise in cone-beam CT (CBCT) with a flat-panel detector.>Methods: This fairly fundamental consideration in CBCT system design and operation was addressed experimentally (using a phantom presenting a uniform medium as well as statistically motivated “clutter”) and theoretically (using a cascaded systems model describing CBCT noise) to elucidate the contributing factors of quantum noise (σQ), electronic noise (σE), and view aliasing (σview). Analysis included investigation of the noise, noise-power spectrum, and modulation transfer function as a function of the number of projections (Nproj), dose (Dtot), and voxel size (bvox).>Results: The results reveal a nonmonotonic relationship between image noise and Nproj at fixed total dose: for the CBCT system considered, noise decreased with increasing Nproj due to reduction of view sampling effects in the regime Nproj <∼200, above which noise increased with Nproj due to increased electronic noise. View sampling effects were shown to depend on the heterogeneity of the object in a direct analytical relationship to power-law anatomical clutter of the form κ/f β—and a general model of individual noise components (σQ, σE, and σview) demonstrated agreement with measurements over a broad range in Nproj, Dtot, and bvox.>Conclusions: The work elucidates fairly basic elements of CBCT noise in a manner that demonstrates the role of distinct noise components (viz., quantum, electronic, and view sampling noise). For configurations fairly typical of CBCT with a flat-panel detector (FPD), the analysis reveals a “sweet spot” (i.e., minimum noise) in the range Nproj ∼ 250–350, nearly an order of magnitude lower in Nproj than typical of multidetector CT, owing to the relatively high electronic noise in FPDs. The analysis explicitly relates view aliasing and quantum noise in a manner that includes aspects of the object (“clutter”) and imaging chain (including nonidealities of detector blur and electronic noise) to provide a more rigorous basis for commonly held intuition and heurism in CBCT system design and operation.
机译:>目的:在平板探测器的锥形束CT(CBCT)中研究投影视图数量对图像噪声的影响。>方法:在CBCT系统的设计和操作中,通过实验(使用表示均匀介质的幻像以及具有统计动机的“杂波”)和理论上(使用描述CBCT噪声的级联系统模型)进行了研究,以阐明量子噪声(σQ)的影响因素,电子噪声(σE)和视图混叠(σview)。分析包括对噪声,噪声功率谱和调制传递函数的研究,这些函数是投影数(Nproj),剂量(Dtot)和体素大小(bvox)的函数。>结果:结果揭示了固定总剂量下图像噪声与Nproj之间的非单调关系:对于所考虑的CBCT系统,由于Nproj <〜200范围内视图采样效果的降低,噪声随Nproj的增加而降低,高于Nproj时,噪声随Nproj的增加而增加电子噪音。结果表明,视图采样效果取决于对象的异质性,与κ/ f β形式的幂律解剖杂波以及单个噪声分量的一般模型(σ< em> Q σ E σ视图)显示了与在 N < / em> proj, D tot和 b vox。>结论:这项工作阐明了CBCT噪声的基本元素,从而证明了不同噪声成分(即量子,电子和视图采样噪声)的作用。对于带有平板检测器(FPD)的CBCT相当典型的配置,分析显示出 N proj 范围内的“最佳点”(即最小噪声)。 em> 〜250-350,由于FPD中相对较高的电子噪声, N proj 的值比多探测器CT的典型值低近一个数量级。该分析以一种包括对象(“杂波”)和成像链(包括检测器模糊和电子噪声的非理想性)方面的方式显式地关联了视图混叠和量子噪声,从而为CBCT中通常持有的直觉和启发式提供了更严格的基础系统设计与运行。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号