Assessment of cardiac single-photon emission computed tomography performance using a scanning linear observer.
Assessment of cardiac single-photon emission computed tomography performance using a scanning linear observer.
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DOI：
10.1118/1.4771961
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发表时间：
2012-12
期刊：
影响因子：
3.8
通讯作者：
Chih-Jie Lee;M. Kupinski;L. Volokh
中科院分区：
文献类型：
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作者：
Chih-Jie Lee;M. Kupinski;L. Volokh
目的单光子发射型计算机断层扫描（SPECT）广泛应用于心肌缺血和心肌梗死的诊断。重要的是评估和比较不同的SPECT系统设计，以实现心脏缺陷的最高检测能力。方法Whitaker等.等人关于扫描线性观测器（SLO）的研究[“Estimating random signal parameters from noised images with nuisance parameters：linear and scanning-linear methods，”Opt. Express 16（11），8150-8173（2008）]表明，SLO可用于估计信号的位置和大小。SLO的一个主要优点是它可以与投影数据而不是重建数据一起使用。因此，该观测器模型独立于任何重建算法来评估整体硬件性能。此外，图像质量研究的计算时间也显著减少。在本研究中，评估了基于GE碲锌镉专用心脏SPECT相机Discovery 530 c设计的三个系统。该设计正式命名为Alcyone Technology：Discovery NM 530 c，于2009年8月商业化。三个系统GE 27、GE 19和GE 13分别包含27、19和13个探测器。临床上，人类心脏可以被虚拟地分割成三个冠状动脉区域：左前降支动脉、左旋支动脉和右冠状动脉。心脏SPECT系统最重要的功能之一是产生图像，放射科医生可以根据图像准确预测缺陷存在于哪个区域[http：//www.asnc.org/media/PDFs/PPReporting081511.pdf，美国核心脏病学会指南]。根据投影图像对缺损程度的良好估计也非常有助于确定心肌缺血的严重性。在这项研究中，通过SLO估计缺陷的位置和程度，并通过定位接收器工作特性（LROC）评估系统性能[P. Khurd和G. Gindi，“Decision strategies maximizing the area under the LROC curve，”Proc. SPIE 5749，150-161（2005）]或估计接受者操作特征（EROC）[E.克拉克森，“估计接收器工作特性曲线和理想的观察者联合检测/估计任务，”J. Opt. Soc. Am. A 24，B 91-B 98（2007）]曲线。结果LROC/EROC曲线下面积（AULC/AUEC）和特定假阳性分数（FPF）下的真阳性分数（TPF）可作为优值。对于公差为1 mm的半径估计，GE 27、GE 19和GE 13系统的AUEC值分别为0.8545、0.8488和0.8329，FPF = 5%时的TPF分别为77.1%、76.46%和73.55%。对所有三个系统的评估表明，GE 19系统产生的估计信息和心脏缺陷可检测性非常接近GE 27系统，同时使用的探测器少了8个。因此，可以放心地去除30%的昂贵探测器单元。结论如结果所示，SLO和LROC/EROC曲线的组合可以确定产生最相关估计/检测信息的配置。因此，这是用于评估心脏SPECT系统的有用方法。
PURPOSE Single-photon emission computed tomography (SPECT) is widely used to detect myocardial ischemia and myocardial infarction. It is important to assess and compare different SPECT system designs in order to achieve the highest detectability of cardiac defects. METHODS Whitaker et al.'s study ["Estimating random signal parameters from noisy images with nuisance parameters: linear and scanning-linear methods," Opt. Express 16(11), 8150-8173 (2008)] on the scanning linear observer (SLO) shows that the SLO can be used to estimate the location and size of signals. One major advantage of the SLO is that it can be used with projection data rather than with reconstruction data. Thus, this observer model assesses the overall hardware performance independent of any reconstruction algorithm. In addition, the computation time of image quality studies is significantly reduced. In this study, three systems based on the design of the GE cadmium zinc telluride-based dedicated cardiac SPECT camera Discovery 530c were assessed. This design, which is officially named the Alcyone Technology: Discovery NM 530c, was commercialized in August, 2009. The three systems, GE27, GE19, and GE13, contain 27, 19, and 13 detectors, respectively. Clinically, a human heart can be virtually segmented into three coronary artery territories: the left-anterior descending artery, left-circumflex artery, and right coronary artery. One of the most important functions of a cardiac SPECT system is to produce images from which a radiologist can accurately predict in which territory the defect exists [http://www.asnc.org/media/PDFs/PPReporting081511.pdf, Guideline from American Society of Nuclear Cardiology]. A good estimation of the extent of the defect from the projection images is also very helpful for determining the seriousness of the myocardial ischemia. In this study, both the location and extent of defects were estimated by the SLO, and the system performance was assessed by localization receiver operating characteristic (LROC) [P. Khurd and G. Gindi, "Decision strategies maximizing the area under the LROC curve," Proc. SPIE 5749, 150-161 (2005)] or estimation receiver operating characteristic (EROC) [E. Clarkson, "Estimation receiver operating characteristic curve and ideal observers for combined detection/estimation tasks," J. Opt. Soc. Am. A 24, B91-B98 (2007)] curves. RESULTS The area under the LROC/EROC curve (AULC/AUEC) and the true positive fraction (TPF) at a specific false positive fraction (FPF) can be treated as the figures of merit. For radii estimation with a 1 mm tolerance, the AUEC values of the GE27, GE19, and GE13 systems are 0.8545, 0.8488, and 0.8329, and the TPF at FPF = 5% are 77.1%, 76.46%, and 73.55%, respectively. The assessment of all three systems revealed that the GE19 system yields estimated information and cardiac defect detectability very close to those of the GE27 system while using eight fewer detectors. Thus, 30% of the expensive detector units can be removed with confidence. CONCLUSIONS As the results show, a combination of the SLO and LROC/EROC curves can determine the configuration that yields the most relevant estimation/detection information. Thus, this is a useful method for assessing cardiac SPECT systems.