Recent research led by Carolin Wunderlich from the Istituto Nazionale di Fisica Nucleare (INFN) in Pisa, Italy, has made significant strides in optimizing the design of large gamma cameras used in single-photon emission computed tomography (SPECT). This study, published in the journal Sensors, addresses critical challenges in the medical imaging field, particularly regarding the size, weight, and cost of SPECT systems.
Traditionally, SPECT cameras rely on large scintillator crystals paired with photomultiplier tubes (PMTs), which can weigh several hundred kilograms due to their substantial lead shielding. This bulkiness limits their applicability in smaller spaces and makes them less accessible for various healthcare settings. The research proposes a transformative solution by replacing PMTs with silicon photomultipliers (SiPMs), which are smaller, lighter, and offer higher efficiency.
Wunderlich’s team utilized Geant4 simulations to explore how different pixel designs could enhance both energy and spatial resolution in large SiPM-based gamma cameras. Their findings suggest that it is possible to achieve impressive spatial resolution of just a few millimeters and an energy resolution close to 10% at 140 keV, even with pixels significantly larger than standard commercial SiPMs.
One of the standout innovations from this study is the introduction of large-area SiPM pixels (LASiPs), which are constructed by summing the outputs of multiple SiPMs. This approach minimizes the number of readout channels needed, thus reducing complexity and cost. “The geometry of the pixel also has a huge impact,” Wunderlich noted, emphasizing that a honeycomb structure significantly improves spatial resolution compared to traditional square grids.
The implications of this research extend beyond medical imaging; they present commercial opportunities in the energy sector as well. For instance, the enhanced imaging capabilities could lead to more effective monitoring of nuclear facilities or improved safety protocols in radiological applications. The potential for lighter, more compact SPECT systems could also facilitate their use in remote or resource-limited settings, broadening access to advanced diagnostic tools.
Overall, this work not only advances the field of medical imaging but also opens up new pathways for innovation in related industries. As the demand for efficient and effective imaging solutions grows, the findings from this study could play a pivotal role in shaping the future of SPECT technology.
