초록 ▼

An X-ray CT scanner for producing a CT image of a subject by scanning an X-ray fan beam radiated an X-ray source through the subject in a predetermined slice-thickness direction. The scanner comprises a main detector detecting the X-ray beam to produce an X-ray transmission data of a subject and to

An X-ray CT scanner for producing a CT image of a subject by scanning an X-ray fan beam radiated an X-ray source through the subject in a predetermined slice-thickness direction. The scanner comprises a main detector detecting the X-ray beam to produce an X-ray transmission data of a subject and to a plurality of slices in agreement with unequal segment pitches. The detector comprises a two-dimensional array consisting of a plurality of X-ray detecting elements receiving the X-ray beam and being disposed in the slice-thickness direction as a row line and a channel direction as a column line. The X-ray detection sensitivity distributions of all the segments formed by the detecting elements disposed in predetermined element pitches in the slice-thickness direction are adjusted to be uniform or approximately uniform by controlling various members, devices, or factors which are all controllable for X-ray detection sensitivity, thereby enabling the X-ray transmission data of unequal slice thicknesses to be adjusted in sensitivity slice by slice in the detector. The scanner further comprises a switch group selecting and combining the sensitivity-adjusted X-ray transmission data of the plurality of slices, the selected and combined X-ray transmission data being provided to selected ones of a data acquiring elements of a data acquisition system.

대표청구항 ▼

[ What we claim is:] [1.]1. An X-ray CT scanner for obtaining a computed tomography (CT) image of a subject, the scanner comprising:means for radiating an X-ray fan beam spreading in a slice-thickness direction;means for scanning the subject with the X-ray fan beam;means for detecting the X-ray fan

[ What we claim is:] [1.]1. An X-ray CT scanner for obtaining a computed tomography (CT) image of a subject, the scanner comprising:means for radiating an X-ray fan beam spreading in a slice-thickness direction;means for scanning the subject with the X-ray fan beam;means for detecting the X-ray fan beam transmitted through the subject with a detecting element array including a plurality of X-ray detecting elements two-dimensionally disposed in the slice-thickness direction and a channel direction orthogonal to the slice-thickness direction, the X-ray detecting elements of the array being classified in the slice-thickness direction into a plurality of groups each including at least one channel-directional line of X-ray detecting elements each of which has an aperture to receive the X-ray fan beam, the aperture being changed in width in the slice-thickness direction on a basis of an unequal element pitch when viewed group by group, an output of each X-ray detecting element being converted into an X-ray transmission signal;means for adjusting, element by element, irregularities of X-ray detection sensitivity of the X-ray beam detecting means in the slice thickness direction so that the X-ray detecting elements have substantially the same X-ray detection sensitivity in the slice thickness direction;means for not only selecting at least two channel-directional lines of X-ray detecting elements from the array but also mutually combining the sensitivity-adjusted X-ray transmission signals of the selected at least two channel-directional lines of X-ray detecting elements into the X-ray transmission signals of one or more slices;means for acquiring the selected and combined X-ray transmission signals to process the acquired X-ray transmission signals into projection data of the one or more slices; andmeans for producing the acquired and processed projection data into the CT image.