Method and apparatus for helical scan imaging in X-ray computed tomography

Claim 1

An X-ray computed tomography (CT) apparatus for carrying out a helical scan imaging, comprising: input means for entering a desired imaging region, the desired imaging region having slice planes located at ends of the desired imaging region; a bed plate for supporting a body, including a body axis, to be examined along a direction of said body axis; an X-ray source for irradiating X-rays on the body to be examined on the bed plate, the X-ray source and the bed plate being relatively rotatable with respect to each other at a predetermined angular speed and relatively linearly movable with respect to each other along the direction of the body axis of the body to be examined; a detector for detecting the X-rays irradiated by the X-ray source and penetrated through the body to be examined; data collection means for collecting data from the X-rays detected by the detector according to the desired imaging region entered by the input means; image reconstruction means for reconstructing tomographic images according to the data collected by the data collection means; and control means for controlling a relative linear motion of the X-ray source and the bed plate according to the desired imaging region entered by the input means such that the X-ray source and the bed plate are relatively linearly moved through a distance covered by a scanning region appropriate for the data collection means to collect the data required by the image reconstruction means to reconstruct the tomographic images for the desired imaging region, the scanning region including the desired imaging region and supplementary interpolation data regions, each of the supplementary interpolation data regions being located at the ends of the desired imaging region and utilized in carrying out interpolations for deriving data in the desired imaging region.

Claim 12

A method of a helical scan imaging in an X-ray computed tomography (CT), comprising the steps of: placing a body to be examined on a bed plate; entering a desired imaging region, the desired imaging region having slice planes located at ends of the desired imaging region; relatively linearly moving the bed plate and an X-ray source for irradiating X-rays on the body to be examined with respect to each other along a direction of a body axis of the body to be examined, while relatively rotating the bed plate and the X-ray source with respect to each other at a predetermined angular speed; detecting the X-rays irradiated by the X-ray source and penetrated through the body to be examined by a detector; collecting data from the X-rays detected by the detector according to the desired imaging region entered at the entering step; reconstructing tomographic images according to the data collected at the collecting step; and automatically controlling a relative linear motion of the bed plate and the X-ray source according to the desired imaging region entered at the entering step such that the X-ray source and the bed plate is relatively linearly moved through a distance covered by a scanning region appropriate for the collecting step to collect the data required by the reconstructing step to reconstruct the tomographic images for the desired imaging region, the scanning region including the desired imaging region and supplementary interpolation data regions, each of the supplementary interpolation data regions being located at the ends of the desired imaging region and utilized in carrying out interpolations for deriving data in the desired imaging region.

Claim 13

A method of a helical scan imaging in an X-ray computed tomography (CT), comprising the steps of: placing a body to be examined on a bed plate; entering a desired imaging region, the desired imaging region having slice planes located at ends of the desired imaging region; relatively linearly moving the bed plate and an X-ray source for irradiating X-rays on the body to be examined with respect to each other along a direction of a body axis of the body to be examined, while relatively rotating the bed plate and the X-ray source with respect to each other at a predetermined angular speed; detecting the X-rays irradiated by the X-ray source and penetrated through the body to be examined by a detector; collecting data from the X-rays detected by the detector according to the desired imaging region entered at the entering step; reconstructing tomographic images according to the data collected at the collecting step; and automatically controlling a relative linear motion of the bed plate and the X-ray source according to the desired imaging region entered at the entering step such that the X-ray source and the bed plate is relatively linearly moved through a distance covered by a scanning region appropriate for the collecting step to collect the data required by the reconstructing step to reconstruct the tomographic images for the desired imaging region, the scanning region including the desired imaging region and supplementary interpolation data regions, each of the supplementary interpolation data regions being located at the ends of the desired imaging region and utilized in carrying out interpolations for deriving data in the desired imaging region.