Scatter elimination technique and apparatus in radionuclide emission and transmission imaging in a nuclear camera

A method for reducing scatter error in transmission or emission images, said method comprising:

• collecting a planar photon image formed of counts collected in a matrix of pixels, each pixel including position coordinates and an energy spectrum for photons collected at said position coordinates;
• dividing said image into a plurality of local areas, each local area including at least one pixel;
• determining a global scatter curve;
• forming a local scatter curve for each local area by scaling the global scatter curve according to the ratio of counts within a known energy normalization window for said local area and for said global scatter curve;
• using respective local scatter curves to estimate a local scatter correction factor for each local area;
• and
• applying respective local scatter correction factors to said image.

A method for reducing scatter error in transmission or emission images, said method comprising:

• collecting a planar photon image formed of counts collected in a matrix of pixels, each pixel including position coordinates and an energy spectrum for photons collected at said position coordinates;
• dividing said image into a plurality of local areas, each local area including at least one pixel;
• calculating a local energy centroid for each local area;
• calculating a total energy centroid for said image;
• using the spectra of local areas having respective energy centroids less than a known threshold percentage of the total energy centroid to determine a global scatter curve
• determining a global scatter count of photons in said global scatter curve within a known energy normalization window;
• determining a local scatter count of photons in each said local area within said normalization window;
• determining a local scatter curve for each local area by scaling said global scatter curve by a normalizing ratio of each respective local scatter count to said global scatter count;
• determining a local photopeak total count of photons in each said local area within a photopeak energy window;
• determining a local photopeak scatter count of photons in each said local scatter curve within said photopeak energy window;
• determining a local correction factor for each local area from a correction ratio of each respective local photopeak scatter count to said local photopeak total count;
• and
• applying each local correction factor to a respective local area to provide a scatter corrected image.