Investigation of Axial and Angular Sampling in Multi-Detector Pinhole-SPECT Brain Imaging.
Investigation of Axial and Angular Sampling in Multi-Detector Pinhole-SPECT Brain Imaging.
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DOI：
10.1109/tmi.2020.3015079
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发表时间：
2020-12
影响因子：
10.6
通讯作者：
King MA
中科院分区：
文献类型：
--
作者：
Zeraatkar N;Kalluri KS;Auer B;Konik A;Fromme TJ;Furenlid LR;Kuo PH;King MA
我们设计了一个专用的多探测器多针孔脑SPECT扫描仪，以生成更高质量的图像相比，通用系统。该系统，AdaptiSPECT-C，旨在适应其灵敏度，分辨率的权衡，通过改变其光圈配置，允许高灵敏度动态和高空间分辨率静态成像。目前的系统设计包括23个探测器头排列在一个截断的球形几何形状。在这项工作中，我们研究了当前固定系统设计的轴向和角度采样能力。还评价了使用机架有限旋转的两种数据采集方案和使用成像床轴向平移的另外两种数据采集方案通过改进采样对图像质量的影响。在当前原型系统中增加角度和轴向采样导致图像质量指标的定量改善和图像的定性外观，如在使用专门选择的体模的研究中所确定的。具有临床分布的脑幻影的视觉改善不太明显，但在保真度（归一化均方根误差（NRMSE））和纹状体特异性结合率（SBR）的多巴胺转运蛋白（DAT）分布，以及在NRMSE和脑灌注分布的活动恢复方面呈现定量改善。随着采样的增加，在对比度恢复系数、偏倚和脑灌注分布中病变的变异系数方面观察到了更明显的改善。还确定了探测器的最颅环对轴向采样的影响可以忽略不计，但其对感兴趣成像体积的颅侧部分中的灵敏度和角度采样的显著影响。
We designed a dedicated multi-detector multi-pinhole brain SPECT scanner to generate images of higher quality compared to general-purpose systems. The system, AdaptiSPECT-C, is intended to adapt its sensitivity-resolution trade-off by varying its aperture configurations allowing both high-sensitivity dynamic and high-spatial-resolution static imaging. The current system design consists of 23 detector heads arranged in a truncated spherical geometry. In this work, we investigated the axial and angular sampling capability of the current stationary system design. Two data acquisition schemes using limited rotation of the gantry and two others using axial translation of the imaging bed were also evaluated concerning their impact on image quality through improved sampling. Increasing both angular and axial sampling in the current prototype system resulted in quantitative improvements in image quality metrics and qualitative appearance of the images as determined in studies with specifically selected phantoms. Visual improvements for the brain phantoms with clinical distributions were less pronounced but presented quantitative improvements in the fidelity (normalized root-mean-square error (NRMSE)) and striatal specific binding ratio (SBR) for a dopamine transporter (DAT) distribution, and in NRMSE and activity recovery for a brain perfusion distribution. More pronounced improvements with increased sampling were seen in contrast recovery coefficient, bias, and coefficient of variation for a lesion in the brain perfusion distribution. The negligible impact of the most cranial ring of detectors on axial sampling, but its significant impact on sensitivity and angular sampling in the cranial portion of the imaging volume-of-interest were also determined.