Designstudie eines µCT-Zusatzes für einen hochauflösenden Positronen-Emissions-Tomographen: Beispiel für ein multimodales bildgebendes System

Each tomographic system provides its specific view to the living body. While Xray Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) reveal anatomical details of the human body, Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPELT) yield information on physiologic processes of the human body. Combinations of anatomical and functional imaging systems have been shown to increase the content of diagnostic information. Representing such a system, PET/CT allows a simultaneous viewing of anatomy and metabolism of patients and a CT-based attenuation correction of the complementary emission data. Fueled by the outstanding success of human PET/CT scanners, the interest in the development of PET/CT systems for small animals is growing quickly. This thesis summarizes the research on a MicroCT system for a combined small animal PET/CT. Preliminary investigations, simulations and measurements are described in detail. The approach to describe the CT components by means of the modulation transfer function and the noise power spectrum are presented. To facilitate a systematic selection of the required CT components several CT systems consisting of different detector materials, X-ray sources and filtration have been simulated and analyzed in terms of soft tissue contrast. The performance of the different compositions is investigated. PET/CT scans conducted on non-integrated systems are used to describe the procedure of such a combined PET/CT scan of small animals and the effects of CT-based attenuation correction for the emission data. Furthermore the advantages of an integrated PET/CT system for small animals are summarized and discussed in light of upcoming instrumental development