Improved Bayesian image estimation for digital chest radiography.
Improved Bayesian image estimation for digital chest radiography.
复制标题
改进了数字胸部放射线摄影的贝叶斯图像估计。
DOI：
10.1118/1.598054
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发表时间：
1997
期刊：
影响因子：
3.8
通讯作者：
FloydJr,CE
中科院分区：
文献类型：
--
作者：
Baydush,AH;Bowsher,JE;Laading,JK;FloydJr,CE
在此之前，我们已经证明了空间变化贝叶斯图像估计（SVBIE）可以在不降低图像分辨率的情况下减少数字胸片的散射和提高对比度-噪声比（CNR）。之前的算法使用了一个散射补偿模型，该模型是为发射断层扫描导出的。在这里，我们开发并评估了一种新的迭代SVBIE技术，该技术结合了用于投影放射照相的散点模型。材料和方法使用校准的光刺激磷光体系统获得拟人化胸影的可运动数字x线照片以及定量散射测量。将新的迭代SVBIE技术应用于幻影图像，以减少散射。对散射分数减少、CNR改善和分辨率降低进行了评估。结果14次复查后，肺区残余散点分数降至2%以下，纵隔区残余散点分数降至30%以下。肺区CNR提高了约50%，纵隔提高了187%。分辨率没有降低。结论新的SVBIE技术可以将散射降低到远低于反散射网格提供的水平，并且可以在不损失分辨率的情况下提高CNR。新技术优于以前的贝叶斯技术。
PurposePreviously, we have shown that Spatially Varying Bayesian Image Estimation (SVBIE) can be used to reduce scatter and improve contrast‐to‐noise ratios (CNR) in digital chest radiographs with no degradation of image resolution. This previous algorithm used a model for scatter compensation that was derived for emission tomography. Here, we develop and evaluate a new iterative SVBIE technique that incorporates a scatter model derived for projection radiography.Materials and MethodsPortable digital radiographs of an anthropomorphic chest phantom were obtained along with quantitative scatter measurements using a calibrated photostimulable phosphor system. The new iterative SVBIE technique was applied to the phantom image to reduce scatter. Scatter fraction reduction, CNR improvement, and resolution degradation were evaluated.ResultsResidual scatter fractions were reduced to less than 2% in the lungs and 30% in the mediastinum at 14 iterations. CNR was improved by approximately 50% in the lung region and 187% in the mediastinum. Resolution was not degraded.ConclusionsThe new SVBIE technique can reduce scatter to levels far below those provided by an antiscatter grid and can increase CNR without loss of resolution. The new technique outperforms the previous Bayesian techniques.