SR-NLM: a sinogram restoration induced non-local means image filtering for low-dose computed tomography.
Radiation dose has raised significant concerns to patients and operators in modern X-ray computed tomography (CT) examinations. A simple and cost-effective means to perform a low-dose CT scan is to lower the milliampere-seconds (mAs) as low as reasonably achievable in data acquisition. However, the associated image quality with lower-mAs scans (or low-dose scans) will be unavoidably degraded due to the excessive data noise, if no adequate noise control is applied during image reconstruction. For image reconstruction with low-dose scans, sinogram restoration algorithms based on modeling the noise properties of measurement can produce an image with noise-induced artifact suppression, but they often suffer noticeable resolution loss. As an alternative technique, the noise-reduction algorithms via edge-preserving image filtering can yield an image without noticeable resolution loss, but they often do not completely eliminate the noise-induced artifacts. With above observations, in this paper, we present a sinogram restoration induced non-local means (SR-NLM) image filtering algorithm to retain the CT image quality by fully considering the advantages of the sinogram restoration and image filtering algorithms in low-dose image reconstruction. Extensive experimental results show that the present SR-NLM algorithm outperforms the existing methods in terms of cross profile, noise reduction, contrast-to-ratio measure, noise-resolution tradeoff and receiver operating characteristic (ROC) curves.
['Bian|Zhaoying|Z|', 'Ma|Jianhua|J|', 'Huang|Jing|J|', 'Zhang|Hua|H|', 'Niu|Shanzhou|S|', 'Feng|Qianjin|Q|', 'Liang|Zhengrong|Z|', 'Chen|Wufan|W|']
D000465:Algorithms D006801:Humans D011829:Radiation Dosage D011835:Radiation Protection D011856:Radiographic Image Enhancement D011857:Radiographic Image Interpretation, Computer-Assisted D013902:Radiography, Thoracic D015203:Reproducibility of Results D012680:Sensitivity and Specificity D014057:Tomography, X-Ray Computed
Sinogram restoration Non-local means Image filtering Low-dose CT