ABSTRACT
The development of PET/CT in the early 2000s represents a medical rather than a technical revolution in the field of medical imaging with the introduction in clinical practice of the first-ever multimodality imaging device. On the other hand, the combination of two imaging modalities within the same gantry has provided certain challenges for the accurate fusion of the anatomical and functional information provided by the CT and PET images, respectively. Addressing these challenges is essential in order to ensure the qualitative and quantitative accuracy of the reconstructed images provided by this new imaging modality. One such area concerns the use of the CT images for attenuation correction purposes in PET. In all of these applications accounting for differences in the respiration conditions during the PET and CT acquisitions is an essential prerequisite. This chapter provides an overview of the essential developments in the attenuation and respiratory motion correction methodologies for PET/CT imaging. It is worth noting that much of the techniques developed initially for respiratory motion correction in PET/CT are also applicable in other subsequent multimodality systems, such as PET/MRI.
