University of Arizona College of Optical Sciences, 1630 E. University Boulevard, Tucson, Arizona 85721, USA.
Med Phys. 2007 Jul;34(7):3034-44. doi: 10.1118/1.2745920.
The multi-module, multi-resolution system (M3R) is used for hardware assessment in objective, task-based signal detection studies in projection data. A phantom capable of generating multiple realizations of a random textured background is introduced. Measured backgrounds from this phantom are used along with simulated lumpy and uniform backgrounds to investigate signal-to-noise ratio as a function of exposure time. Results are shown to agree with theoretical predictions, exhibiting a power-law like dependence previously seen for studies performed either in simulation or without an imaging system, and help validate the use of simulated lumpy backgrounds in observer studies. A second study looks at signal-detection performance, measured by AUC (area under the receiver operating characteristic curve), in lumpy backgrounds for 20 M3R aperture combinations as a function of lump size and signal size. Observer performance reveals an improvement in AUC for certain ranges of signal and lump combinations through the use of multiplexed, multiple-pinhole apertures, indicating a need for task-specific aperture optimization. The channelized Hotelling observer is used with Laguerre-Gauss channels for both observer studies. Methods for selection of number of channels and channel width are discussed.
多模块、多分辨率系统（M3R）用于在基于目标的客观信号检测研究中的硬件评估。引入了一种能够生成随机纹理背景的多个实现的体模。使用来自该体模的测量背景以及模拟的块状和均匀背景来研究信噪比作为曝光时间的函数。结果与理论预测一致，表现出与以前在模拟中或没有成像系统的情况下进行的研究相同的幂律依赖性，并有助于验证在观察者研究中使用模拟块状背景。第二项研究着眼于在块状背景下使用 AUC（接收器操作特性曲线下的面积）测量的信号检测性能，对于 20 种 M3R 孔径组合，作为块状大小和信号大小的函数。观察者性能表明，通过使用复用、多针孔孔径，在某些信号和块状组合范围内，AUC 得到了提高，这表明需要针对特定任务进行孔径优化。通道化 Hotelling 观察者与拉盖尔-高斯通道一起用于这两项观察者研究。讨论了选择通道数量和通道宽度的方法。
