Abstract: A multi-slice X-ray CT scanner is provided to realize high resolution and a wide scanned region in a slice-thickness direction for an object. In the X-ray CT scanner, an X-ray beam for slice imaging is radiated toward an object and scanned in a predetermined slice-thickness direction, a direction orthogonal to the slice-thickness direction being defined as a channel direction. The scanner comprises a two-dimensional X-ray detector, a data acquisition system, and an electrically combining unit. The detector has a plurality of X-ray detecting elements arranged in a two-dimensional array of both rows in the slice-thickness direction and columns in the channel direction, the detecting elements of each row being arranged in unequal pitches. The data acquisition system has a plurality of data acquiring elements arranged in a two-dimensional array of rows and columns, acquiring signals detected by the two-dimensional X-ray detector, and producing digital data proportional to the detected signals.

Abstract: In a computed tomography apparatus which irradiates an X-ray ray fan beam to a slice of a subject body from various directions around the slice, detects the image data of the X-ray ray that has passed the subject body to obtain projection data, and performs reconstruction computation on the projection data to acquire the tomographic image of the slice of the subject body, a main detector which has a plurality of rows of detection elements are aligned in association with a plurality of slices of the subject body and detects projection data of a plurality of slices at a time, a profile detector which has the same number of rows of detection elements as the main detector and measures a profile in the slice direction of the amount of X-ray ray incident to the main detector, and a data processing device for compensating the projection data output from the main detector in accordance with the output of the profile detector.