RADIOGRAPHIC APPARATUS FOR DETECTING PHOTONS WITH OFFSET CORRECTION

摘要

The invention relates to a detection apparatus for detecting photons, such as used in radiographic imaging systems. A detection unit (14) generates detection signal pulses having a detection signal pulse height being indicative of the energy of the detected photons (13), wherein a detection values generation unit (16) generates energy-resolved detection values depending on the detection signal pulses. A signal pulse generation unit (15) generates artificial signal pulses having a predefined artificial signal pulse height and a predefined generated rate. The detection values generation unit (16) determines an observed rate being the rate of the artificial signal pulses having an artificial signal pulse height being larger than a predefined threshold as observed by the detection values generation unit (16) and determines an offset of the detection signal pulses depending on the determined observed rate. This allows reliably determining the offset of the detection signal pulses, such as produced by dark current drift in radiographic detection devices, which can be used for correcting the finally generated detection values.

主权项

1. A detection apparatus for detecting photons, the detection apparatus comprising:
a detection unit for detecting photons, wherein the detection unit is adapted to generate detection signal pulses having a detection signal pulse height being indicative of the energy of the respective detected photon, a detection values generation unit for generating energy-resolved detection values depending on the detection signal pulses, a signal pulse generation unit for generating artificial signal pulses having a predefined artificial signal pulse height and a predefined generated rate and for providing the generated artificial signal pulses to the detection values generation unit, wherein the detection values generation unit is adapted to a) receive the artificial signal pulses, b) determine an observed rate being the rate of the received artificial signal pulses having an artificial signal pulse height being larger than a predefined first threshold, wherein the predefined first threshold is larger than the predefined artificial signal pulse height, and c) determine an offset of the detection signal pulses depending on the determined observed rate of the artificial signal pulses.