Patent ID: 8742360

Claim:
A Compton camera comprising: at least one processor; at least one computer-readable medium; a plurality of camera heads each comprising a plurality of detectors, each camera head placed in a position capable of detection of radiation emitted from a target object, detecting Compton scattering due to the radiation and outputting detection data comprising Compton cones; wherein at least two of the camera heads are placed such that normal lines passing through the center of their respective detection planes cross at right angles; a first reconstruction unit for reconstructing a two-dimensional projected image; wherein at least one of the computer-readable media stores instructions to instruct at least one of the processors to cause the first reconstruction unit to perform the steps of: determining a crossing point at which the normal lines of the at least two camera heads cross; and for each of the at least two camera heads, determining a two-dimensional plane located at the crossing point and parallel to the detection plane of the camera head and two-dimensionally projecting each of the Compton cones obtained from the detection data output from the camera head onto said two-dimensional plane to form a two-dimensional projected image; a determining unit for determining a second three-dimensional region; wherein at least one of the computer-readable media stores instructions to instruct at least one of the processors to cause the determining unit to perform the steps of: for each of the at least two camera heads, generating a first three-dimensional region determined by a set of straight lines each connecting between a point on the two-dimensional projected image and a point on the detection plane; and determining the common portions of the first three-dimensional regions determined for each of the at least two camera heads to form a second three-dimensional region; and a second reconstruction unit for reconstructing an image based on a radiation source; wherein at least one of the computer-readable media stores instructions to instruct at least one of the processors to cause the second reconstruction unit to perform the step of three-dimensionally projecting each of the Compton cones obtained from the detection data output from each of the plurality of camera heads onto the second three-dimensional region determined by the determining unit.