Performance assessment and in-vivo imaging using the VUB-PET system

At the Vrije Universiteit Brussel (VUB), a high resolution PET scanner based on 3×3×20 mm BaF₂ crystals and read out by a photosensitive wire chamber has been constructed, the main features of which have been reported previously. The system is currently undergoing performance assessment at the Institute of Cancer Research/Royal Marsden NHS Trust (London, UK), where the aim is to develop the role of non-invasive imaging applied to the pre-clinical evaluation of new PET radiotracers in oncology. A hardware upgrade has been implemented, which has resulted in an eightfold increase in the data acquisition rate to an average 130 Kcps. Examination of scatter profiles derived from line source measurements made in air and in water confirm that the main component arises from interactions outside the object being imaged, supporting the use of straightforward correction methods based on curves fitted to sinogram profiles. Experiments have been carried out using cylindrical and spherical phantoms, in order to investigate aspects of processing and quantitation relevant to tumour imaging. The feasibility of of imaging radiotracer kinetics in-vivo using the VUB PET system has been demonstrated using [¹⁸F]-fluorodeoxyglucose combined with a dynamic acquisition protocol