X-ray computerized tomographic imaging method and imaging system capable of forming scanogram data from helically scanned data.

摘要

In an X-ray CT (computerized tomographic) imaging method, scano data is produced from X-ray projection image data about a helically-scanned biological body (20) under medical examination. The X-ray projection image data are acquired only at a predetermined projection angle such as 0 DEG during a helical scanning operation. Accordingly, no X-ray projection to acquire the scano data is required to reduce X-ray dose given to the biological body (20). The X-ray CT imaging method comprises the steps of: scanning a biological body (20) under medical examination in a helical scanning mode, while relatively rotating an X-ray tube (10) and an X-ray detector (12) around the biological body (20) translated along a longitudinal axis of the biological body (20), to acquire X-ray projection image data about the helically-scanned biological body (20); selecting only X-ray projection image data acquired at a predetermined projection angle from the entire X-ray projection image data obtained at the helical-scanning step; processing said selected X-ray projection image data to produce a scanogram (22) of said helically-scanned biological body (20); and reconstructing an X-ray CT image (21) of said helically-scanned biological body (20) based upon said entire X-ray projection image data, whereby both of said scanogram (22) and said X-ray CT image (21) are substantially simultaneously displayed.