X-RAY CT APPARATUS, A METHOD FOR CHANGING THE HELICAL PITCH, AN IMAGE RECONSTRUCTION PROCESSING APPARATUS, AN IMAGE RECONSTRUCTION PROCESSING METHOD, AND AN IMAGE RECONSTRUCTION PROCESSING PROGRAM

摘要

The X-ray CT apparatus that performs a scan after a pre-scan, comprising a reconstruction part reconstructing the pre-scan image of said subject to be examined from transmission data detected by said detector during said pre-scan, and also reconstructing the scan image of said subject to be examined from the transmission data detected by said detector during said scan; and a scan controlling part initiating a scan by directly changing the helical pitch of said bed from the stopped position for said pre-scan to the position toward an ending edge of the reconstruction area of the image. The scan controlling part initiates the scan at a first helical pitch by which X-rays for a predetermined number of views can be emitted at a starting edge of the reconstruction area of the image, and, after X-rays for the predetermined number of views is emitted, the scan at a second helical pitch continues.