Task Equivalence for Model and Human-Observer Comparisons in SPECT Localization Studies.
Task Equivalence for Model and Human-Observer Comparisons in SPECT Localization Studies.
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SPECT 定位研究中模型和人类观察者比较的任务等效性。
DOI：
10.1109/tns.2016.2542042
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发表时间：
2016
影响因子：
1.8
通讯作者：
Gifford,HowardC
中科院分区：
文献类型：
--
作者：
Sen,Anando;Kalantari,Faraz;Gifford,HowardC
虽然数学模型观察者是为了有效地评估医学成像系统，但他们的发现应该与作为主要临床最终用户的人类观察者相关。我们已经研究了在模型和人类观察者任务之间追求对等是否有助于确保这一目标。一项定位接受者工作特征（LROC）研究测试了模拟in -111 SPECT成像与拟人化幻象的前列腺病变检测。测试图像为从重建体中提取的二维切片。采用高斯后平滑迭代有序集期望最大化（OSEM）重建算法。迭代次数和后过滤水平的变化定义了研究中的测试策略。比较了视觉搜索（VS）观测器、扫描信道化Hotelling观测器和扫描信道化非预白化（CNPW）观测器的性能。这些模型观察者被应用于目标感兴趣区域（roi）的精确信息。ROI知识是人类观察者的一个研究变量。在一种研究形式中，人类单独阅读SPECT图像。采用双模态格式，SPECT图像与从幻体密度图中提取的解剖图像切片一起呈现。以LROC曲线下面积为评分标准。人类观测器在双模态格式下表现明显更好，并且与模型观测器的相关性也得到了改善。考虑到来自SPECT研究格式的人类观察者数据，模型观察者的Pearson相关系数为0.58 (VS),（CH）和（CNPW）。基于双模态研究中人类观察者数据的系数分别为0.72,0.27和。这些结果表明，在模型-观察者研究中，VS观察者将继续发展，以增强任务等价性。
While mathematical model observers are intended for efficient assessment of medical imaging systems, their findings should be relevant for human observers as the primary clinical end users. We have investigated whether pursuing equivalence between the model and human-observer tasks can help ensure this goal. A localization receiver operating characteristic (LROC) study tested prostate lesion detection in simulated In-111 SPECT imaging with anthropomorphic phantoms. The test images were 2D slices extracted from reconstructed volumes. The iterative ordered sets expectation-maximization (OSEM) reconstruction algorithm was used with Gaussian postsmoothing. Variations in the number of iterations and the level of postfiltering defined the test strategies in the study. Human-observer performance was compared with that of a visual-search (VS) observer, a scanning channelized Hotelling observer, and a scanning channelized nonprewhitening (CNPW) observer. These model observers were applied with precise information about the target regions of interest (ROIs). ROI knowledge was a study variable for the human observers. In one study format, the humans read the SPECT image alone. With a dual-modality format, the SPECT image was presented alongside an anatomical image slice extracted from the density map of the phantom. Performance was scored by area under the LROC curve. The human observers performed significantly better with the dual-modality format, and correlation with the model observers was also improved. Given the human-observer data from the SPECT study format, the Pearson correlation coefficients for the model observers were 0.58 (VS),(CH), and(CNPW). The respective coefficients based on the human-observer data from the dual-modality study were 0.72, 0.27, and. These results point towards the continued development of the VS observer for enhancing task equivalence in model-observer studies.