@article{oai:niigata-u.repo.nii.ac.jp:00002562,
 author = {Takahashi, Noriyuki and Lee, Yongbum and Tsai, Du-Yih and Ishii, Kiyoshi},
 issue = {5},
 journal = {Radiation Medicine, Radiation Medicine},
 month = {Jun},
 note = {Purpose: To evaluate the performance of a novel noise reduction filter for improving the visibilty of early CT signs of hyperacute stroke on nonenhanced CT images. Material and Methods: Fourteen patients with middle cerebral artery occlusion within 4.5 hours after onset were used for evaluations. Signal-to-noise ratio (SNR) of the processed images with the noise reduction filter and that of original images were measured. Moreover, two neuroradiologists visually rated all the processed and original images on the visibility of normal and abnormal gray-white matter interface. Results: The SNR value of the processed images was approximately eight times as high as that of the original images, and a 87% reduction of noise was achieved using this technique. In the visual assessment, the results showed that both the visibility of normal gray-white matter interface and that of the loss of the gray-white matter interface were significantly improved by using the proposed method (p<0.05). Conclusion: The noise reduction filter proposed in the present study has the potential to improve the visibility of early CT signs of hyperacute stroke on nonenhanced CT images.},
 pages = {247--254},
 title = {A novel noise reduction filter for improving visibiligy of early CT signs of hyperacute stroke: evaluation of the filter's performance : Preliminary clinical experience},
 volume = {25},
 year = {2007}
}