Patent ID: 8588362

Claim:
A computed tomography (CT) imaging system comprising: an x-ray source configured to emit a beam of x-rays toward an object to be imaged; a detector configured to receive the x-rays attenuated by the object; a multi-position x-ray filter positioned between the x-ray source and the object, the multi-position x-ray filter comprising: a filter element configured to spectrally filter the beam of x-rays; and a magnet structure configured to selectively generate a magnetic field so as to cause the filter element to move between a filter position and a non-filter position; a data acquisition system (DAS) operably connected to the detector; and a computer operably connected to each of the x-ray source, the x-ray filter, and the DAS, the computer being programmed to: cause the x-ray source to emit x-rays at each of a first kVp and a second kVp toward the detector; control the multi-position x-ray filter to position the filter element in the non-filter position during emission of the x-rays at the first kVp; and control the multi-position x-ray filter to position the filter element in the filter position during emission of the x-rays at the second kVp; wherein positioning the filter element in the filter and non-filter positions comprises causing current to be provided to the magnet structure so as to generate a magnetic field configured to move the filter element to the filter and non-filter positions at high frequency, into and out of a path of the beam of x-rays.