Scintillation camera for establishing the coordinates of a radiation stimuli produced by a radiation field
AssigneeElscint Ltd.
InventorsJacob Zioni, Yitzhak Klein, Dan Inbar
Life of this patent
Estimating the term…
Abstract
A scintillation camera has a planar scintillating crystal that produces light events whose spatial distribution corresponds to the spatial distribution of the radiation stimuli causing such events, and a plurality of photomultipliers having photocathodes for receiving light from the crystal through a planar face thereof. Computing circuitry coupled to the photomultipliers computes the projection of a light event in the crystal on a reference axis by forming an analytical function of the outputs of the photomultipliers according to the spatial location of the light event in the crystal.
Claims33
A scintillation camera comprising:
- a. a planar, unitary scintillating crystal responsive to radiation stimuli for producing light events at spatial locations corresponding to the spatial locations of the interactions of the stimuli with the crystal;
- b. a plurality of photomultipliers positioned with their optical axes perpendicular to the plane of the crystal and having photocathodes for receiving light from the crystal, each photomultiplier producing an output in response to a light event in the crystal;
- and
- c. computing circuitry coupled to said photomultipliers for computing the projection of a light event in the crystal on a reference axis including means for forming an analytical function of the outputs of only those photomultipliers that are close to the light event in the crystal without attenuating such outputs.
A scintillation camera comprising:
- a. a planar, unitary scintillating crystal responsive to radiation stimuli for producing light events at spatial locations corresponding to the spatial locations of the interactions of the stimuli with the crystal;
- b. a plurality of photomultipliers positioned with their optical axis perpendicular to the plane of the crystal and having photocathodes for receiving light from the crystal, each photomultiplier producing an output in response to a light event in the crystal;
- and
- c. computing circuitry coupled to said photomultipliers for combining the outputs thereof to compute the projection on a reference axis of a light event in the crystal, including means responsive to the spatial location of the light event for selecting the photomultipliers whose outputs are to be combined and for determining the manner in which such outputs are combined.
In a scintillation camera having a scintillating crystal responsive to radiation stimuli for producing light events at spatial locations corresponding to the spatial locations of the interactions of the stimuli with the crystal, a plurality of photomultipliers for receiving light from the crystal and producing outputs in response to light events in the crystal, and computing circuitry for computing the coordinates of a light event using the outputs of the photomultipliers, the improvement in which comprises:
- means for delaying the application of the outputs of the photomultipliers to the computing circuitry while a measure of the total energy of a light event is computed, and for applying the delayed outputs to the computing circuitry only if said measure exceeds a threshold.
In a scintillation camera having a scintillating crystal responsive to radiation stimuli for producing light events at spatial locations corresponding to the spatial locations of the interactions of the stimuli with the crystal;
- a plurality of photomultipliers for receiving light from the crystal and producing outputs in response to light events in the crystal, and an integrator for integrating the outputs of the photomultipliers as part of the computation circuitry by which the coordinate of a light event is computed, the improvement in which comprises a gated integrator for integrating the photomultiplier outputs.
In a scintillation camera having a scintillating crystal responsive to radiation stimuli for producing light events at spatial locations corresponding to the spatial locations of the interactions of the stimuli with the crystal, a plurality of photomultipliers for receiving light from the crystal and producing outputs in response to a light event in the crystal;
- and computing circuitry for computing the coordinates of a light event using the outputs of the photomultipliers;
- the improvement in which includes base line restoration means operating on the outputs of the photomultipliers before such outputs are applied to the computing circuitry.
Dependencies are inferred from the claim text.