Al-Hinnawi Abdel Razzak, Daear Mohammed, Huwaijah Said
Electrical and Mechanical Engineering Faculty FMEE, Biomedical Engineering Department, Damascus University, Airport Street, PO Box 86, Damascus, Syria.
Radiol Phys Technol. 2013 Jul;6(2):385-98. doi: 10.1007/s12194-013-0212-7. Epub 2013 Apr 20.
A bilateral filter (BF) is a non-linear filter that has been proved to de-noise images without overrunning edges. Multi-slice computerized tomography (CT) may employ a BF to participate in dose reduction. This paper quantifies the role of the BF in achieving this objective on 1/2-dose CT. Two sets of CT images are acquired for the chest-pelvis at two different radiation doses. The BF was applied on the 1/2-dose CT images by use of various window sizes. Each time, a set of values of the BF range was fixed while the BF domain was modified. The goal was to observe the behavior of the BF on 1/2-dose CT images in comparison with full-dose CT images. The comparison was carried out by use of four co-occurrence matrix descriptors. Additionally, the peak signal-to-noise ratio (PSNR) and the mean square error (MSE) were reported. The study was applied to the sagittal, coronal, and axial CT views. The results showed that the impact of applying a BF varies among different CT views. The BF can retrieve only part of the signal being lost due to reduction of the radiation dose by one half. Yet, the BF improves the appearance of the 1/2-dose chest-pelvis CT examination. Thus, the BF can contribute to a 50% dose reduction. A procedure for employing the BF on CT machines is proposed. The results also showed that texture descriptors are similar to the PSNR and MSE in providing quantities for assessing medical image quality.
双边滤波器（BF）是一种非线性滤波器，已被证明能够在不跨越边缘的情况下对图像进行去噪。多层计算机断层扫描（CT）可采用双边滤波器来参与剂量降低。本文量化了双边滤波器在1/2剂量CT上实现这一目标的作用。在两种不同辐射剂量下采集了两组胸部-骨盆CT图像。通过使用各种窗口大小，将双边滤波器应用于1/2剂量CT图像。每次，在修改双边滤波器域时，固定一组双边滤波器范围值。目的是观察双边滤波器在1/2剂量CT图像上与全剂量CT图像相比的表现。通过使用四个共生矩阵描述符进行比较。此外，还报告了峰值信噪比（PSNR）和均方误差（MSE）。该研究应用于矢状面、冠状面和横断面CT视图。结果表明，应用双边滤波器的影响在不同CT视图中有所不同。双边滤波器只能找回因辐射剂量减半而丢失的部分信号。然而，双边滤波器改善了1/2剂量胸部-骨盆CT检查的外观。因此，双边滤波器有助于将剂量降低50%。提出了在CT机器上使用双边滤波器的程序。结果还表明，纹理描述符在提供评估医学图像质量的量方面与PSNR和MSE相似。
