The Infinity hardware lab specializes in the design of SPECT and PET systems. During the last years we have gained experience in radiation detector design, collimator design and system design. The radiation detectors are based on PSPMTs, DSiPMs or analog SiPMs. Custom algorithms have been developed to identify the position of interaction in the detector. We have good contacts with several machining companies to produce SPECT collimators. For this we can choose from traditional techniques (milling, drilling) or additive manufacturing. In-house developed algorithms are used for system calibration and for 3D image reconstruction.
- Performance of dSiPM for PET applications
- Performance of dSiPMs for compact SPECT scanners
- SPECT pinhole collimator for optimal detector usage
Digital silicon photomultipliers (dSiPM) are solid-state single-photon sensitive devices made of arrays of Geiger-mode avalanche photodiodes (SPAD), in which each SPAD is integrated with CMOS logic circuitry. The integrated CMOS logic provides trigger, precise timestamp, programmable control logic and digital readout for every SPAD. These properties make dSiPM a promising photosensor to be used for Positron Emission Tomography (PET); for both clinical and preclinical applications.
In our research we investigate the use of dSiPM for developing a new generation of PET detectors.
Our current interest is focused on evaluating the use of the dSiPM for preclinical PET imaging. Through the combination of the dSiPM with thin monolithic scintillation crystals and 3D events positioning algorithms we achieved compact PET detectors with a sub-millimeter spatial resolution suitable for high-resolution preclinical PET imaging systems.
Basing on these detectors we have developed so far two prototypes of compact, high-resolution PET scanner dedicated for mice and rats imaging.
|Figure 1: First prototype of our dedicated small animal PET scanner based on dSiPM and thin monolithic scintillators.||Figure 2: Second prototype of our dedicated small animal PET scanner with higher sensitivity and larger field of view (FOV).||Figure 3: A reconstructed image of the Derenzo phantom obtained with our second PET scanner. Rods with the diameter of 0.8 mm can be resolved.|
Most preclinical single photon emission computed tomography (SPECT) scanners are based on clinical detectors, resulting in systems with a large footprint. Recently, Philips Digital Photon Counting (PDPC) has introduced a compact, fully digital detector based on solid state technologies, the digital silicon photomultiplier (dSiPM). We are investigating the use of these dSiPMs in combination with thin, monolithic LYSO scintillator crystals as single photon detectors for the development of a compact small animal SPECT scanner.
|Figure 1: dSiPM structure||Figure 2: Measurement setup|
In single-photon emission computed tomography (SPECT), multi-pinhole collimation is used to avoid overlap (multiplexing) of the projections on the detector. However, because of the circular projections of the conventional pinholes the detector surface is not entirely used. We designed a new pinhole geometry called the lofthole, which by its rectangular shape ensures optimal detector usage.
|Figure 1: lofthole collimator|