Abstract In an exemplary embodiment, a measuring arrangement for irradiating the radiography subject from different directions comprises a radiation source which emits a radiation beam which penetrates the layer to be examined, its dimension perpendicular to the layer plane being equal to the layer thickness, and a radiation receiver supplies electrical output signals which correspond to the radiation intensity measured. A computer calculates, from the output signals, the attenuation values of specific image points of the irradiated body layer. Correction devices are provided in the radiation beam with which the radiation quality (mean energy) of the radiation impinging on the receiver is determined, each preferably comprising several detectors arranged in series in the direction of radiation and separated from one another by a luminescent layer. The output signals of the correction detectors serve to correct for the radiation hardening in the patient. Correction detectors according to the disclosure are particularly suitable for use in apparatus with which fluoroscopic layer images capable of being evaluated in medical diagnosis are produced.
Diagnostic radiology apparatus for producing layer images of a radiography subject with a patient support, having a measuring arrangement for irradiating the radiography subject from different directions, comprising a radiation source which emits a radiation beam which penetrates the layer to be examined, the dimensions of said radiation beam perpendicular to the layer plane being equal to the layer thickness, and a radiation receiver which supplies electrical output signals which correspond to the radiation intensity measured, and having a computer connected to the radiation receiver for calculating from the output signals of the radiation receiver the attenuation values of specific points of the irradiated body layer, said radiation receiver comprising correction detector and absorber means for the radiation disposed in series such that output signals are supplied defining the mean radiation energy of the radiation receiver, characterized in that said correction detector and absorber means comprises an absorber in the form of a luminescent layer (9c) and at least two correction detectors (9a, 9b) arranged in series in the direction of radiation and separated from one another by the luminescent layer (9c), said luminescent layer converting the radiation received into light to which the correction detectors are sensitive characterized in that the correction detectors (9a, 9b) of said correction detector and absorber means (9) have respective correction detector outputs, and a summing circuit connected with said correction detector outputs and having an output channel for supplying a summation signal which is a function of the signals supplied by said correction detectors.
Claim 2
Dependent Claim
251 words
Diagnostic radiology apparatus for producing layer images of a radiography subject with a patient support, having a measuring arrangement for irradiating the radiography subject from different directions, comprising a radiation source which emits a radiation beam which penetrates the layer to be examined, the dimensions of said radiation beam perpendicular to the layer plane being equal to the layer thickness, and a radiation receiver which supplies electrical output signals which correspond to the radiation intensity measured, and having a computer connected to the radiation receiver for calculating from the output signals of the radiation receiver the attenuation values of specific points of the irradiated body layer, said radiation receiver comprising correction detector and absorber means for the radiation disposed in series such that output signals are supplied defining the mean radiation energy of the radiation receiver, characterized in that said correction detector and absorber means comprises an absorber in the form of a luminescent layer (9c) and at least two correction detectors (9a, 9b) arranged in series in the direction of radiation and separated from one another by the luminescent layer (9c), said luminescent layer converting the radiation received into light to which the correction detectors are sensitive characterized in that the correction detectors (9a, 9b) of said correction detector and absorber means (9) have respective correction detector outputs, and a summing circuit connected with said correction detector outputs and having an output channel for supplying a summation signal which is a function of the signals supplied by said correction detectors.