Direct monochromatic image generation for spectral computed tomography

A method, comprising:

• acquiring projection data including high energy projection data acquired at a high energy and low energy projection data acquired at a low energy;
• generating a combined image from the high energy projection data and the low energy projection data;
• generating a differential image from the high energy projection data and the low energy projection data;
• and
• generating a monochromatic image at a monochromatic energy from the combined image and the differential image.

A system, comprising:

• an x-ray source that emits a beam of x-rays toward an object to be imaged;
• a detector that receives the x-rays attenuated by the object;
• a data acquisition system (DAS) operably connected to the detector;
• and
• a computing device operably connected to the DAS and configured with executable instructions in non-transitory memory that when executed cause the computing device to:
• acquire, via the DAS, projection data during a scan of the object;
• reconstruct a low energy image and a high energy image from the projection data;
• generate a combined image from the low energy image and the high energy image;
• generate a differential image from the low energy image and the high energy image;
• and
• generate a monochromatic image at a monochromatic energy from the combined image and the differential image.

A method, comprising:

• acquiring projection data including high energy projection data acquired at a high energy and low energy projection data acquired at a low energy;
• generating a differential image and a combined image directly from the projection data;
• and
• reconstructing a monochromatic image directly from the differential image and the combined image.