Iterative image reconstruction with a sharpness driven regularization parameter

An image reconstructor for generating spectral images with spectral X-ray imaging data produced by a spectral computed tomography scanner, comprising:

• a reconstruction processor configured to perform a first pass of an iterative reconstruction in which an intermediate first spectral image and an intermediate second spectral image are to be generated using an iterative reconstruction algorithm, a start first spectral X-ray image, a start second spectral X-ray image, an initial first spectral regularization parameter, and an initial second spectral regularization parameter;
• and
• an updater configured to update at least one of the initial first spectral regularization parameter or the initial second spectral regularization parameter, thereby creating an updated first spectral regularization parameter or an updated second spectral regularization parameter, based on at least a sharpness of one of the intermediate first spectral image or the intermediate second spectral image,
• wherein the reconstruction processor is configured to perform a subsequent pass of the iterative reconstruction in which an updated intermediate first spectral image and an updated intermediate second spectral image are to be generated using the iterative reconstruction algorithm, the intermediate first spectral image, the intermediate second spectral image, the updated first spectral regularization parameter, and the updated second spectral regularization parameter;
• and
• a display configured to display the generated spectral images.

A computer readable storage medium encoded with computer readable instructions of generating spectral images with spectral X-ray imaging data produced by a spectral computed tomography scanner, the instructions, when executed by a processer, causes the processor to:

• perform a first pass of an iterative reconstruction in which an intermediate first spectral image and an intermediate second spectral image are generated using an iterative reconstruction algorithm, a start first spectral X-ray image, a start second spectral X-ray image, an initial first spectral regularization parameter, and an initial second spectral regularization parameter;
• update at least one of the initial first spectral regularization parameter or the initial second spectral regularization parameter, thereby creating an updated first spectral regularization parameter or an updated second spectral regularization parameter, based on at least a sharpness of one of the intermediate first spectral image or the intermediate second spectral image;
• and
• perform a subsequent pass of the iterative reconstruction in which an updated intermediate first spectral image and an updated intermediate second spectral image are generated using the iterative reconstruction algorithm, the intermediate first spectral image, the intermediate second spectral image, the updated first spectral regularization parameter, and the updated second spectral regularization parameter;
• and
• display the generated spectral images.