| 摘要 |
PROBLEM TO BE SOLVED: To reduce artifact of 3D and MIP images attributed to uneven image noises and eliminate noticeable increase in processing time by applying for a data a filter coefficient determined based on a spiral weight function decided. SOLUTION: An X-ray source 14 of a gantry 12 projects an X-ray beam 16 toward a detector array 18 and a detector 20 detects X rays passing through a patient 22. While a scanning is performed to obtain an X-ray projection data, the gantry 12 and component elements mounted thereon rotate around the center 24 of rotation. A smoothing algorithm is executed by a computer 36, for example, to perform a processing of a data stored in a large-capacity memory 38. At this point, an adaptive smoothing is performed using a filter coefficient. A spiral weighted function (w) (γ, β) is prepared and a filter coefficient is generated according to a standard deviation ratio ξ (γ, ϕ). Then, the filter coefficients thus obtained is used for filtering, namely, smoothing. |
