The Voxel Imaging PET (VIP) pathfinder project, at the IFAE High Energy Physics Institue of Barcelona,
is studying the advantages of using pixelated solid-state technology for nuclear medicine applications. These devices play an important role in the detection and diognosis of cancer and other tumors that affect cellular functions in the body. The VIP project is being funded by FP7-ERC-AG and has started in July 2010 for a period of 48 months.
The VIP project proposes a design based on pixelated solid-state technology with a large number of signal channels for PET detectors to improve both the energy and position resolution with high efficiency compared to state-of-the-art crystal PET detectors. Although the VIP project is especially focussed on PET scanners,the VIP concept can be easily extended for Positron Emission Mammography (PEM) and Compton gamma camera detectors.The special VIP design, using pixelated solid-state material has a number of advantages: an improved energy resolution (and hence a negligible scatter fraction in the data sample), a better depth of interaction estimation (improving the line-of-response (LOR) estimation) and the possibility to operate in a magnetic field (for hybrid MRI-PET operation). The modular design facilitates a flexible detector architecture since the modular units can be stacked according to needs. The trapezoidal shape of the modular unit accounts for less gaps in the PET ring and hence an improved detection efficiency.
A dedicated application specific integrated circuit (ASIC) is designed and produced by the project and will be tested on a prototype proof-of-concept set-up consisting of two back-to-back segments of the PET ring. Each ASIC will be connected to two module units, and has independent read-out channels for each of the voxels.
Speacial dedicated studies are done to study the characterization of solid-state CdTe scintillator material. The results will be compared with simulation models, focussing on charge sharing, heat production and behaviour in a magnetic field.
Simulation studies are done on PET, PEM and Compton cameras, to predict their efficiency performance, signal-to-noise ratio and the image reconstruction quality. An additional effort is taken in evaluating the optimal image reconstruction algorithm.