The effects of object activity distribution on multiplexing multi-pinhole SPECT.
The effects of object activity distribution on multiplexing multi-pinhole SPECT.
复制标题
物体活动分布对多针孔 SPECT 的影响。
DOI：
10.1088/0031-9155/56/8/019
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发表时间：
2011-04-21
影响因子：
3.5
通讯作者：
Beekman FJ
中科院分区：
文献类型：
--
作者：
Mok GS;Tsui BM;Beekman FJ
我们的目的是研究放射性分布的影响，多路复用多针孔（MPH）SPECT。使用了三种数字体模，包括热棒、冷棒和冷球体模。通过（i）调整相同4针孔准直器的MPH图案（方案1）和（ii）增加针孔的数量（方案2）获得不同程度的复用。使用3D分析MPH投影仪基于相同的采集时间生成无噪声和噪声投影。使用OS-EM重建投影，无需分辨率恢复。评估了归一化均方误差（NMSE）、噪声、图像轮廓和信号背景比（SBR）。对于热棒体模，方案2中的复用设计的NMSE噪声权衡略有改善。观察到大量的伪影，并且对于冷体模的复用设计，NMSE噪声权衡略微恶化。对于冷棒体模，分辨率略微降低，以实现更高程度的多路复用（~39-65%）。对于冷球体模，图像轮廓显示非多路复用设计更好地模拟了体模，而与SBR中的非多路复用相比，约20%的多路复用的性能相似。我们的研究结果表明，多路复用可以帮助稀疏对象，但导致显着的图像退化在非稀疏分布。由于许多示踪剂不是高度特异性的，并且通过允许多路复用而获得的检测效率的增益被图像劣化相当抵消，因此对于最佳MPH准直器设计，多路复用需要保持在最小值。
We aim to study the effects of activity distribution for multiplexing multi-pinhole (MPH) SPECT. Three digital phantoms, including a hot rod, a cold rod and a cold sphere phantom, were used. Different degrees of multiplexing were obtained by (i) adjusting the MPH pattern for the same 4-pinhole collimator (scheme 1) and (ii) increasing the number of pinholes (scheme 2). Noise-free and noisy projections were generated using a 3D analytical MPH projector based on the same acquisition time. Projections were reconstructed using OS–EM without resolution recovery. Normalized mean-square-error (NMSE), noise, image profiles and signal-to-background ratios (SBR) were assessed. For the hot rod phantom, the NMSE-noise trade-offs slightly improves for multiplexing designs in scheme 2. Substantial artifacts were observed and the NMSE-noise trade-offs slightly worsened for multiplexing designs for the cold phantoms. Resolutions slightly degraded for higher degrees of multiplexing (~39–65%) for the cold rod phantom. For the cold sphere phantom, image profiles showed non-multiplexing designs better emulated the phantom, while ~20% multiplexing performs similarly as compared to non-multiplexing in SBR. Our results indicate that multiplexing can help for sparse objects but leads to a significant image degradation in non-sparse distributions. Since many tracers are not highly specific, and the gain of detection efficiency by allowing multiplexing is fairly offset by image degradations, multiplexing needs to be kept to a minimum for optimum MPH collimator designs.
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影响因子：
10.6
作者：
Wang, Yuchuan;Tsui, Benjamin M. W.
通讯作者：
Tsui, Benjamin M. W.
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通讯作者：
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