Author(s): Matthew Memmott

Hospital: Manchester University NHS Foundation Trust

Reference: RAD Magazine, 46, 541, 24

Excerpt: 

CT-based attenuation correction (AC) is a fundamental component of clinical PETCT imaging and its accuracy is dependent on the integrity of the CT data. The method for AC is a multi-step process, starting with conversion of CT data to the equivalent mass-attenuation coefficient for 511keV photons (μ511keV), reduction of the data volume to that of the intended PET reconstruction and application of a blurring function to account for the spatial resolution of the scanner. This results in what is commonly known as the μ-map. This is then used for the generation of the respective attenuation correction factor at each voxel location in sinogram space, ultimately being included in the projector of the reconstruction algorithm.