Apparatus and method for dynamic calibration of spectral CT with rotating X-ray source and stationary energy discriminating detectors

摘要

An apparatus and method for dynamically calibrating a computed-tomography (CT) scanner that includes a rotating X-ray source and a plurality of stationary energy-discriminating detectors configured to capture incident X-ray photons emitted from the X-ray source. A bowtie filter with a unique geometry and material composition is used to generate reference beams of a desired intensity. The apparatus includes a processor that is configured to remove a scattering background based on data obtained from the reference beams and compute a change in a predetermined calibration function.

主权项

1. A computed-tomography (CT) apparatus, comprising:
a rotating X-ray source; a plurality of stationary energy-discriminating detectors configured to capture incident X-ray photons emitted from the X-ray source; a bowtie filter configured to generate reference beams of respective desired intensities outside a scan field of view; and a processor configured to
obtain reference count rates corresponding to the reference beams incident on a detector outside the scan field of view, andupdate a calibration function based on the obtained reference count rates at the detector, wherein the updated calibration function is used to determine X-ray intensities from scan count rates obtained at the detector when the detector is within the scan field of view.