The improvement of the SNR of the low-dose CT image is a crucial issue for the low-dose CT application.As studied before,the noise in the calibrated and log-transformed projection data of low-mA(or low-dose) CT protocol follows approximately a non-stationary Gaussian distribution.In this study,we further demonstrate that some isolated noise points would not satisfy the above observation.Hence,we propose a noise reduction scheme for low-dose CT sinograms,which includes isolated datum detection and removal,MA...