A method of statistical image restoration for a low-dose CT image using a deep learning, the method includes increasing a number of channels of the low-dose CT image, which is an input image, and decreasing a size of an activation map of the low-dose CT image using an encoder, passing the activation map generated by the encoder to a plurality of residual blocks, and increasing the size of the activation map passed through the residual blocks and generating a denoised result image using a decoder.