Inclusion of quasi-vertex views in a brain-dedicated multi-pinhole SPECT system for improved imaging performance.
Inclusion of quasi-vertex views in a brain-dedicated multi-pinhole SPECT system for improved imaging performance.
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DOI：
10.1088/1361-6560/abc22e
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发表时间：
2021-01-27
影响因子：
3.5
通讯作者：
中科院分区：
文献类型：
--
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对于采用针孔孔径的脑专用多检测器系统，使用面向患者头部顶部的检测器（即，准顶点视图）可以提供从靠近大脑处进行额外观察的优点，以改善检测器覆盖范围。在本文中，我们报告的模拟和重建研究的结果，调查的影响，准顶点视图的成像性能的AdaptiSPECT-C，大脑专用的固定SPECT系统正在开发中。在该设计中，来自大脑下方区域的初级光子和散射光子都可能影响准顶点视图采集的SPECT投影，从而降低AdaptiSPECT-C成像性能。在这项工作中，我们确定了比例，起源和性质（即，主要、散射和多重散射）的计数，这些计数是从头部和全身的结构发出的，有助于从不同的AdaptiSPECT-C探测器环以及从真正的顶视图探测器进行投影。我们模拟了用于评估图像质量不同方面的幻影（即，均匀的放射性浓度球，和Derenzo），以及具有模拟临床123 I放射性分布的不同计数水平的拟人幻影（即，DaTscan和灌注）。我们确定，患者体内的衰减和散射大大降低了感兴趣体积外发射的光子到达探测器并在15%的峰值能量窗口内被记录的概率。此外，我们证明了在系统采集中包含此类计数的残差不会降低目视判读或定量分析。准顶点探测器的加入增加了体积灵敏度、角度采样和空间分辨率，从而显著增强了图像质量，尤其是在大脑的纹状体-丘脑和上级区域。此外，准顶点检测器的使用改善了临床相关指标的恢复，如纹状体结合率和选定大脑结构的平均活性。我们的研究结果证明了用123 I试剂进行脑成像的准顶点环的有用性，可以推广到其他常用的用同位素标记的SPECT成像剂，如99 mTc和可能的111 I。
With brain-dedicated multi-detector systems employing pinhole apertures the usage of detectors facing the top of the patient’s head (i.e., quasi-vertex views) can provide the advantage of additional viewing from close to the brain for improved detector coverage. In this paper, we report the results of simulation and reconstruction studies to investigate the impact of the quasi-vertex views on the imaging performance of AdaptiSPECT-C, a brain-dedicated stationary SPECT system under development. In this design, both primary and scatter photons from regions located inferior to the brain can contribute to SPECT projections acquired by the quasi-vertex views, and thus degrade AdaptiSPECT-C imaging performance. In this work, we determined the proportion, origin, and nature (i.e., primary, scatter, and multiple-scatter) of counts emitted from structures within the head and throughout the body contributing to projections from the different AdaptiSPECT-C detector rings, as well as from a true vertex view detector. We simulated phantoms used to assess different aspects of image quality (i.e., uniform activity concentration sphere, and Derenzo), as well as anthropomorphic phantoms with different count levels emulating clinical 123I activity distributions (i.e., DaTscan and perfusion). We determined that attenuation and scatter in the patient’s body greatly diminish the probability of the photons emitted outside the volume of interest reaching to detectors and being recorded within the 15% photopeak energy window. In addition, we demonstrated that the inclusion of the residual of such counts in the system acquisition does not degrade visual interpretation or quantitative analysis. The addition of the quasi-vertex detectors increases volumetric sensitivity, angular sampling, and spatial resolution leading to significant enhancement in image quality, especially in the striato-thalamic and superior regions of the brain. Besides, the use of quasi-vertex detectors improves the recovery of clinically relevant metrics such as the striatal binding ratio and mean activity in selected cerebral structures. Our findings proving the usefulness of the quasi-vertex ring for brain imaging with 123I agents can be generalized to other commonly used SPECT imaging agents labelled with isotopes, such as 99mTc and likely 111I.
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影响因子：
2.6
作者：
Chen, Ling;Tsui, Benjamin M. W.;Mok, Greta S. P.
通讯作者：
Mok, Greta S. P.
影响因子：
10.6
作者：
Barrett, Harrison H.;Furenlid, Lars R.;Whitaker, Meredith K.
通讯作者：
Whitaker, Meredith K.
影响因子：
9.3
作者：
Bailey, Dale L.;Willowson, Kathy P.
通讯作者：
Willowson, Kathy P.
影响因子：
3.8
作者：
El Fakhri, G;Ouyang, J;Kijewski, MF
通讯作者：
Kijewski, MF
DOI：
10.2214/ajr.106.2.347
发表时间：
1969-01-01
期刊：
AMERICAN JOURNAL OF ROENTGENOLOGY RADIUM THERAPY AND NUCLEAR MEDICINE
影响因子：
--
作者：
HOLMES, RA
通讯作者：
HOLMES, RA