Apparatus and method for material decomposition of spectrally resolved projection data using singles counts

An apparatus, comprising:

• processing circuitry configured to
• obtain first projection data having a plurality of energy components, the first projection data representing total counts including single X-ray detection events and multiple X-ray detection events, the total counts representing X-ray radiation detected at a plurality of energy-resolving detector elements;
• obtain second projection data having a plurality of energy components, wherein the second projection data represents singles counts of the single X-ray detection events, the singles counts representing the X-ray radiation detected at the plurality of energy-resolving detector elements;
• and
• determine a material decomposition by
• estimating a plurality of pairs of projection lengths using a material decomposition of the second projection data, each of the plurality of pairs of projection lengths locally optimizing a material-decomposition method;
• and
• generating a plurality of estimates of the first projection data using the plurality of pairs of projection lengths to determine an attenuation of the X-ray radiation, and
• selecting, as the material-decomposition, a pair of the plurality of pairs of projection lengths corresponding to an estimate of the plurality of estimates of the first projection data that is closest to the first projection data.

An apparatus, comprising:

• processing circuitry configured to
• obtain first projection data, the first projection data representing integrated energies of X-ray radiation detected at a plurality of energy integrating detector elements;
• obtain second projection data having a plurality of energy components, wherein the second projection data represents singles counts, the singles counts representing detection events of single X-ray photons detected at a plurality of energy-resolving detector elements;
• and
• determine a pair of projection lengths using a combined material decomposition of the second projection data and the first projection data, wherein
• the pair of projection lengths optimize a combined cost function that uses a first distance measure between the first projection data and a model of the first projection data and uses a second distance measure between the second projection data and a model of the second projection data.

An apparatus, comprising:

• an X-ray source radiating X-rays;
• a plurality of detector elements each configured to
• detect a plurality of energy components of the X-rays that are radiated from the X-ray source,
• generate first projection data representing total counts including a combination of single X-ray detection events and multiple X-ray detection events at each of the plurality of detector elements, and
• generate second projection data representing singles counts including the single X-ray detection events at each of the plurality of detector elements;
• and
• processing circuitry configured to
• determine a material decomposition by
• estimating a first pair of projection lengths using a material decomposition of the first projection data, the first pair of projection lengths being a solution of a first material-decomposition method, and
• estimating a second pair of projection lengths using a material decomposition of the second projection data, the second pair of projection lengths being a solution of a second material-decomposition method.

A method, comprising:

• obtaining first projection data having a plurality of energy components, the first projection data representing total counts including single X-ray detection events and multiple X-ray detection events, the total counts representing an intensity of X-ray radiation having been transmitted through an object and then detected at a plurality of energy-resolving detector elements;
• obtaining second projection data having the plurality of energy components, wherein the second projection data represents singles counts of the single X-ray detection events, the singles counts representing the intensity of X-ray radiation having been transmitted through the object and then detected at the plurality of energy-resolving detector elements;
• and
• determining a material decomposition by
• estimating a first pair of projection lengths using a material decomposition of the first projection data, the first pair of projection lengths being a solution of a first material-decomposition method, and
• estimating a second pair of projection lengths using a material decomposition of the second projection data, the second pair of projection lengths being a solution of a second material-decomposition method.