Systems and methods for calibrating a gamma camera
AssigneeGeneral Electric Company
InventorFloribertus Philippus Heukensfeldt Jansen
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Abstract
Methods and systems for calibrating a digital gamma camera using a hole phantom are described. In one embodiment, the method includes the steps of performing offset adjustments and gain adjustments, and then using a source to flood the hole phantom, image data of the phantom is collected by the camera to be calibrated. The image data collected from such flood is used to generate a light distribution function for the camera. In addition, residual distortions are measured, and a spatial corrections map and an energy deficit map are created. A quality control image also can be generated to verify that the camera is calibrated.
Claims13
A method for operating a gamma camera, the gamma camera including a scintillation crystal responsive to radiation stimuli for producing light events in the crystal at locations where the stimuli interact with the crystal and an array of photomultiplier tubes which responds to the light events for producing individual electrical signal outputs, the camera further including a plurality of analog-to-digital converters for converting the electrical signal outputs from the photomultiplier tube array to digital signals, said method comprising the steps of:
- obtaining image data by performing at least one flood exposure using a phantom having a plurality of openings;
- determining positions of individual openings as represented in the image data;
- corresponding the image data representative of the openings to actual openings in the phantom;
- generating a hit map
- generating a histogram representative of signal strength received, and distance from, an event for at least one photomultiplier tube;
- and
- determining residual displacement errors by performing flood exposures at selected energy levels.
A system for operating a gamma camera, the gamma camera including a scintillation crystal responsive to radiation stimuli for producing light events in the crystal at locations where the stimuli interact with the crystal and an array of photomultiplier tubes which responds to the light events for producing individual electrical signal outputs, the camera further including a plurality of analog-to-digital converters for converting the electrical signal outputs from the photomultiplier tube array to digital signals, said system comprising:
- a radioactive source;
- a phantom having a plurality of openings located in front of the camera and between the camera and said radioactive source;
- and
- a computer coupled to the camera, said computer programmed to:
- obtain image data from a flood exposure of the phantom;
- using the obtained image data, determine a light distribution function for the camera;
- and
- determine residual displacement errors from image data collected from collected from flood exposures performed at selected energy levels.
Dependencies are inferred from the claim text.