Patent ID: 7498584

Claim:
A method of selective energy imaging of X-radiation comprising the steps of: a. providing an imaging pixel structure having photodetector means for converting incident radiation to electrical charge; first charge storage means; first charge transfer control means for controlling transfer of charge from the photodetector to the first charge storage means; and first readout means for reading out charge from the first charge storage means; b. setting the first charge transfer control means to prevent transfer of a first charge from the photodetector means to the first charge storage means; c. accumulating the first charge in the photodetector means from radiation incident on the photodetector means in a first portion of a time-varying energy spectrum emitted by a radiation source, corresponding to a first predetermined energy range selected from the energy spectrum; d. setting the first charge transfer control means to transfer the first charge from the photodetector means to the first charge storage means; e. using the first readout means to read out the first charge from the first charge storage means; f. setting the first charge transfer control means to prevent transfer of a second charge from the photodetector means to the first charge storage means; g. accumulating the second charge in the photodetector means from radiation incident on the photodetector in a second portion of the time-varying energy spectrum emitted by the radiation source corresponding to a second predetermined energy range selected from the energy spectrum; h. setting the first charge transfer control means to transfer the second charge from the photodetector means to the first charge storage means; and i. reading out the second charge from the first charge storage means.