Local threshold for segmented attenuation correction of PET imaging of the thorax

A local threshold for segmented attenuation correction technique has been developed for positron emission tomography using short (2-3 minutes) post-injection transmission scans. The technique implements an optimal threshold method on localized histograms to get pseudo-anatomic segmentation on transmission images. Theoretical values of attenuation coefficients are assigned to corresponding anatomic regions. Emission images are reconstructed using attenuation correction factors computed by forward-projecting segmented transmission images. Phantoms and clinical cardiac images are studied using this technique. The technique corrects emission images with accuracy similar to the standard, pre-injection method, reduces noise in the corrected emission images, and offers the potential for increased patient throughput by enabling shorter, post-injection data acquisition