Patent ID: RE41197

Claim:
A method for operating a panoramic imaging apparatus to provide improved tomographic cephalometric images, the panoramic imaging apparatus being capable of operating in a mode in which an X-ray source and radiation sensor, spaced from said radiation X- ray source at a first distance, are rotated about an intermediate vertical rotation center to provide a panoramic image from a subject positioned between the X-ray source and the radiation sensor, said method comprising the steps of: positioning a radiation receiver to receive radiation from said X-ray source, said radiation receiver being located at a second distance from said X-ray source greater than said first distance; placing a subject for cephalometric imaging in front of the radiation receiver; projecting radiation from the X-ray source along a horizontal radiation path to apply radiation from the X-ray source to the radiation receiver; carrying out a first motion comprising rotating the X-ray source about the center of rotation while otherwise maintaining the X- ray source generally stationary ; carrying out a second motion comprising horizontally translating the center of rotation in a direction generally transverse to the radiation path during application of the radiation to the radiation receiver; wherein the effective focal spot of the X- ray source is transferred to the general location of the X - ray source ; and carrying out a third motion comprising translating the radiation receiver in a horizontal direction generally transverse to the radiation path, said first, second, and third motions producing a tomographic cephalometric image from the panoramic imaging apparatus for which the effective focal point for the X-ray source has been altered in a manner to reduce differences in vertical and horizontal ratios of enlargement.