Patent ID: 6442229
Filing Date: 2002-08-27
Classification: A61B,G06T

Abstract:
A computed tomography apparatus which includes:a scanning unit which includes a radiation source (S) and a detector unit (16) which is connected thereto in order to detect a conical radiation beam, emitted by the radiation source, after its passage through an examination zone (13), or an object arranged on a table top therein, and to generate corresponding CT data, a drive device (2, 5) for producing a relative motion in the form of a helix, including a rotation about an axis of rotation (14) and a displacement parallel to the axis of rotation, between the scanning unit (S, 16) and the examination zone (13) or the object, a reconstruction unit for reconstructing a three-dimensional CT image from the measuring values produced by the detector unit, and a control unit for controlling the radiation source and the drive device in such a manner that the emission of the radiation beam by the radiation source commences in a start position such and/or ends in a stop position such that the zones which, at the beginning and/or end of the emission, are irradiated by the radiation beam only to an extent that is not adequate for reconstruction are larger underneath the table top, in the direction of the axis of rotation, than above the table top.