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US 5,845,003 AGranted
Detector z-axis gain correction for a CT system
AssigneeGeneral Electric Company
InventorsHui Hu, Guy M. Besson, David M. Hoffman
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AssigneeGeneral Electric Company
InventorsHui Hu, Guy M. Besson, David M. Hoffman
Estimating the term…
The present invention, in one form, corrects any error due to varying z-axis detector cell gains represented in data obtained by a scan in a CT system. In accordance with one form of the present invention, and after correcting the image data for beam-hardening, the data is passed through a highpass filter to remove any data representing relatively slow, or low frequency, changes. Next, the filtered data is clipped and view averaged to remove high frequency data contents due to the objects being imaged. A slope estimate is then created. Using the slope estimate, an error estimate is generated. The error estimate is then subtracted from the beam-hardened corrected data, for example. As a result, errors due to z-axis gain variation of the detector cells are removed from the projection data array.
A system for producing a tomographic image of an object, said system comprising a detector having a plurality of detector cells having known individual gains, said system configured to spatially integrate individual cell signals and to sum the spatially integrated individual cell signals, the number of cells whose output signals are summed based upon a selected slice thickness, and to correct the summed signal for gain errors resulting from summing output signals from a plurality of cells having different individual gains by:
A system for producing a tomographic image of an object, said system comprising a detector having a plurality of detector cells having known individual gains, said system being configured to spatially integrate individual cell signals and to sum the spatially integrated individual cell signals, the number of cells whose output signals are summed based upon a selected slice thickness, and to correct the summed signal for any error resulting from summing output signals from a plurality of cells having different individual gains.
A method for correcting a summed signal generated by spatially integrating individual cell signals and summing the spatially integrated individual cell signals from a plurality of detector cells of a detector in an imaging system for detector cell gain error, the detector cells having known different individual gains, said method comprising the steps of:
Dependencies are inferred from the claim text.