Method and apparatus for correcting multi-modality imaging data

A multi-modality imaging system comprising a first modality unit, a second modality unit, and a computer operationally coupled to the first and second modality units, wherein the computer is programmed to:

• adjust a tube current of a computed tomography (CT) imaging system to a first tube current value sufficient to generate an attenuation correction map, the first tube current value being less than a second tube current value used to generate diagnostic quality CT images;
• generate a plurality of CT projection data from the CT imaging system, wherein the first tube current value has an associated x-ray flux that produces negative values in the CT projection data,
• preprocess the CT projection data to generate preprocessed CT projection data;
• filter the preprocessed CT projection data to reduce the effect of electronic noise to generate filtered CT projection data;
• and
• perform a minus logarithmic operation on the filtered CT projection data to convert the negative values to positive values to generate at least one of corrected positron emission tomography (PET) data or corrected Single Photon Emission Computed Tomography (SPECT) data.

A non-transitory computer readable medium encoded with a program programmed to instruct a computer to:

• adjust a tube current of a computed tomography (CT) imaging system to a first tube current value sufficient to generate an attenuation correction map, the first tube current value being less than a second tube current value used to generate diagnostic quality CT images;
• generate a plurality of CT projection data from the CT imaging system, wherein the first tube current value has an associated x-ray flux that produces negative values in the CT projection data,
• preprocess the CT projection data to generate preprocessed CT projection data;
• filter the preprocessed CT projection data to reduce electronic noise to generate filtered CT projection data;
• and
• perform a minus logarithmic operation on the filtered CT projection data to convert the negative values to generate corrected at least one of corrected positron emission tomography (PET) data or corrected Single Photon Emission Computed Tomography (SPECT) data.