MEDISIP Medical Imaging and Signal Processing Group, Ghent University, IBBT-IBiTech, iMinds Medical IT, Ghent, Belgium In Time-of-Flight PET/MRI systems accurate attenuation correction, based on the MRI image, is not straight forward. An alternative is attenuation correction based on emission data only. This is for instance done by simultaneous reconstruction of attenuation and activity with th...

Approved: __________________________________ Thesis Supervisor __________________________________ Title and Department __________________________________ Date 1 EVALUATION OF ATTENUATION AND SCATTER CORRECTION REQUIREMENTS IN SMALL ANIMAL PET AND SPECT IMAGING

UNLABELLED Quantitative PET imaging relies on accurate attenuation correction. Recently, there has been growing interest in combining state-of-the-art PET systems with MR imaging in a sequential or fully integrated setup. As CT becomes unavailable for these systems, an alternative approach to the CT-based reconstruction of attenuation coefficients (μ values) at 511 keV must be found. Deriving μ...

A major step towards quantitative SPECT imaging may be achieved if attenuation, scatter and blurring effects are accounted for in the reconstruction process. Here we consider an approach which simultaneously estimates the unknown attenuation coefficient and the emission source using the emission data only. This leads to an inverse mathematical problem which could no longer be solved via iterati...

Following PET/CT, PET/MR is the newest diagnostic whole-body hybrid imaging modality. Simultaneous PET and MR data acquisition requires novel technical solutions and offers new diagnostic opportunities. Attenuation correction (AC) and motion correction (MC) of PET data are current hot topics in PET/MR hybrid imaging research. The added diagnostic value of PET/MR in whole-body imaging is current...

Segmented attenuation correction is now a widely accepted technique to reduce noise propagation from transmission scanning in positron emission tomography (PET). In this paper, we present a new method for segmenting transmission images in whole-body scanning. This reduces the noise in the correction maps while still correcting for differing attenuation coefficients of specific tissues. Based on...

The impact of MR-guided attenuation correction (compared to CT-based AC) on the diagnosis anosmia based 99m-Tc Ethyl-Cysteinate-Dimer SPECT images

AIM Respiratory motion affects cardiac PET-computed tomography (CT) imaging by reducing attenuation correction (AC) accuracy and by introducing blur. The aim of this study was to compare three approaches for reducing motion-induced AC errors and evaluate the inclusion of respiratory motion correction. MATERIALS AND METHODS AC with a helical CT was compared with averaged cine and gated cine CT...