Enhanced photon detection for scanner
AssigneeAnalogic Corporation
InventorDoug Abraham
Life of this patent
Estimating the term…
Abstract
The techniques described herein provide for correcting for pulse pile-up and/or charge sharing in a radiation scanner (100). It finds particular application with the use of a pixilated radiation detector (116) (e.g., a photon counting detector). A circuit (200), comprising a plurality of comparators (204, 206, 208), is configured to determine the energy spectrum of a pulse produced from a photon strike. If the energy spectrum is greater than the energy range for a pulse produced by a single photon strike given an input spectrum and/or if pulses produced from adjacent pixels have temporal coincidence, pulse pile-up and/or charge sharing may be identified and a correction mechanism/correction factors may be applied to determine an actual number of photons that struck the detector (116).
Claims23
A multi-energy imaging apparatus comprising:
- a first circuit configured to identify an energy of a first pulse emitted from an energy resolving detector and to emit a first circuit output indicative of the energy, the first circuit comprising at least three comparators, a first comparator thresholded at a level indicative of a low energy radiation event, a second comparator thresholded at a level indicative of a higher energy radiation event, and a third comparator thresholded at at least one of:
- a level below the level indicative of the low energy radiation event, or
- a level greater than the level indicative of the higher energy radiation event;
- and
- a data acquisition component operably coupled to the first circuit and configured to identify at least one of charge sharing or pulse pile-up based upon the first circuit output and to correct for the at least one of charge sharing or pulse pile-up.
A method for determining a characteristic of a photon, comprising:
- receiving a first pulse generated by a first pixel of a pixelated radiation detector and a second pulse generated by a second pixel of the pixelated radiation detector, the first pulse and the second pulse generated responsive to a radiation event;
- identifying, by a first circuit operably coupled to the first pixel, a characteristic of the first pulse;
- identifying, by a second circuit operably coupled to the second pixel, a characteristic of the second pulse;
- determining whether the second circuit received the second pulse within a first predetermined time period of the first circuit receiving the first pulse;
- and
- combining information related to the characteristic of the first pulse and information related to the characteristic of the second pulse when the second circuit received the second pulse within the first predetermined time period of the first circuit receiving the first pulse to determine a characteristic of the radiation event.
A method comprising:
- receiving a pulse emitted from an energy resolving detector responsive to a radiation event;
- and
- comparing the pulse to at least three thresholds to generate a first circuit output, where:
- a first threshold corresponds to a minimum threshold for a low energy radiation event,
- a second threshold corresponds to a minimum threshold for a higher energy radiation event, and
- a third threshold corresponds to at least one of:
- a minimum threshold for a charge sharing event wherein a charge associated with the radiation event is shared between at least two pixels of the energy resolving detector, or
- a maximum threshold for the higher energy radiation event.
A system for determining a characteristic of a photon, comprising:
- a first circuit operably coupled to a first pixel of a pixelated radiation detector and configured to:
- receive a first pulse generated by the first pixel responsive to a radiation event, and
- determine a characteristic of the first pulse;
- a second circuit operably coupled to a second pixel of the pixelated radiation detector and configured to:
- receive a second pulse generated by the second pixel responsive to the radiation event, and
- determine a characteristic of the second pulse;
- and
- a data acquisition component operably coupled to the first circuit and the second circuit and configured to:
- determine whether the second circuit returned to a clear condition within a predetermined time period of the first circuit returning to the clear condition, and
- combine information related to the characteristic of the first pulse and information related to the characteristic of the second pulse when the second circuit returned to the clear condition within the predetermined time period of the first circuit returning to the clear condition to determine a characteristic of the radiation event.
Dependencies are inferred from the claim text.