Breathing and metal artefact reduction in combined PET/CT imaging

Medical imaging has an established role in the clinical management of most cancers. One of these medical imaging techniques is positron emission tomography (PET). For a PET scan a radioactive-labelled tracer, a radiopharmaceutical, is injected intravenously in the patient. Depending on the used radiopharmaceutical, different biological processes can be visualized. At the moment, the most widely used PET-tracer is a radioactive glucose analogue (¹⁸F-fluorodeoxyglucose or FDG) that accumulates in cells with an increased glucose metabolism (for instance cancer cells). FDG-PET can be used to detect and stage malignant disease, but can also be used to determine tumour volume and tumour boundaries, and to evaluate the treatment effect. Currently, PET is performed in combination with morphological imaging (CT or MRI) to improve localization of lesions. Besides the additional anatomical information for hybrid PET imaging, CT and MR are also used to correct the PET data for attenuation of photon.
In this thesis an overview of the most recent developments and techniques in the field of PET/CT is given. Two of these techniques are being addressed in more detail in the following chapters. These chapters focus on the reduction of errors (artefacts) caused by the combination of PET and computer tomography (CT) imaging, specifically respiratory motion artefacts and metal artefacts. Innovations in artefact correction techniques will have a significant impact on the improvement of quality and accuracy of multimodality imaging techniques.