Abstract
The present studies were performed to investigate a new noise reduction filter algorithm which can be applicable for pediatric body CT images and a method which automatically detects the scan angle and range in the head CT examination. The filter was based on a three-dimensional post-processing, in which output pixel values are calculated by multi-directional one-dimensional median filters. From results of phantom studies, the proposed algorithm could reduce standard deviation values (SD) as a noise index by up to 30% without affecting on the spatial resolution of all directions. The results of the visual evaluation of the peripheral portal vein branches in clinical abdomen images indicated that the visibility of the portal vein was significantly improved (p = 0.042). The scan angle and range detection method for head CT was based on a Hough transformation and a cross-correlation technique. For the 30 clinical cases, the accuracy of the determined scan angle was 1.0±0.7 degrees, and the determined results were evaluated as "acceptable" by five radiological technologists in 93% of the cases. These studies will be useful for image improvement, dose reduction and operation support in CT.
