Finding Optimized Conditions of Slit-Slat and Multislit-Slat Collimation for Breast Imaging.
Finding Optimized Conditions of Slit-Slat and Multislit-Slat Collimation for Breast Imaging.
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寻找用于乳房成像的狭缝板条和多狭缝板条准直的优化条件。
DOI：
10.1109/tns.2011.2177912
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发表时间：
2012
影响因子：
1.8
通讯作者：
Metzler,ScottD
中科院分区：
文献类型：
--
作者：
Kau,Daekwang;Metzler,ScottD
为了研制基于狭缝板条和多狭缝板条准直器的单光子发射计算机断层扫描（SPECT）乳腺成像系统，我们对准直器的几何参数进行了优化。在这项研究中，我们采用了两个独立的度量来验证每个结果：1）基于Cramer-Rao下限（CRB）的信噪比（SNR）和2）来自集合的相同噪声水平下的对比度。我们计算SNR值使用前向投影数据的拟人数字体模包含两个病变的乳房（一个在胸壁，另一个在中心）与模拟狭缝板条准直器作为准直器的几何参数的函数。我们还计算了对比度值与噪声重建图像。基于缝翼情况下的结果，我们研究了多缝翼的角度范围，信噪比和对比度。我们看到了这两个指标的相似趋势。多狭缝狭缝的一个有趣的特性是成像性能取决于侧狭缝的视场（FOV）的取向。当我们比较狭缝缝翼和多狭缝缝翼的度量值时，仅当病变在侧狭缝的FOV中时才看到改善。因此，调整多狭缝板条的参数以最佳地检测胸壁处的病变可能是明智的选择，因为狭缝板条已经为中心和浅表病变提供了良好的图像质量。
In order to develop a breast-imaging system for Single Photon Emission Computed Tomography (SPECT) using slit-slat and multislit-slat collimators, we searched for optimized geometric parameters of the collimators. For this study, we employed two independent metrics to validate each result: 1)Signal to Noise Ratio (SNR) based on the Cramer-Rao lower Bound (CRB) and 2) contrast at the same noise level from an ensemble. We calculated SNR values using forward-projection data of an anthropomorphic digital phantom containing two lesions in the breast (one at the chest wall and the other at the center) with a simulated slit-slat collimator as a function of the collimator's geometric parameters. We also calculated contrast values from reconstructed images with noise. Based on the results from the slit-slat case, we investigated angular range, SNR, and contrast for the multislit-slat. We saw similar trends of the two metrics. One interesting property of the multislit-slat is that the imaging performance depends on the orientation of the field of view (FOV) of the side slits. When we compared the metric values for the slit-slat and multislit-slat, improvement was seen only when the lesion was in the FOV of the side slits. Therefore, tuning the parameters of the multislit-slat to optimally detect lesions at the chest wall might be a sensible option since the slit-slat already provides good image quality for center and superficial lesions.