Computer tomography apparatus with resiliently mounted radiation detector

Claim 1

A computer tomography apparatus comprising: a rotatable frame having a central opening in which an examination subject is disposed, said frame moving in an orbit around said examination subject; an x-ray source mounted on said frame having a focus from which a fan-shaped x-ray beam emanates which transirradiates said examination subject; a detector attached to said frame and disposed for receiving radiation from said x-ray source attenuated by said patient and generating electrical signals corresponding to the measured radiation, said detector having a detector focus on an axis of symmetry of said detector; means for constructing an image of a cross-section of said patient from said signals; means for deflecting the focus of said x-ray source in a plane perpendicular to said axis of symmetry of said radiation detector; means for resiliently mounting said radiation detector on said frame for permitting slight movement of said radiation detector substantially tangentially relative to the orbit of said radiation detector around said examination subject; and means for controlling said means for deflecting said focus to change the position of the focus dependent upon the detector position relative to said frame so that the focus of the x-ray source and the focus of the detector are maintained coincident during rotation of said frame.