“γ-eye”: A paradigm shift in scintigraphic mouse imaging

Abstract

Introduction-purpose Small animal imaging has been well proven as a robust tool to non-invasively study the biodistribution of various biomolecules. A number of imaging systems are commercially available but with high purchase and maintenance costs. For this reason, we present the “ γ -eye”, a dedicated γ -camera suitable for in-vivo scintigraphic molecular imaging. The “ γ -eye” is a unique benchtop system with 5 × 10 cm 2 field-of-view for whole-body mouse imaging. Materials & methods The “ γ -eye” is based on two PositionSensitivePhotomultiplierTubes H8500 coupled to a CsINa pixelated scintillator and a low energy parallel hexagonal hole collimator. The external dimensions of the entire system, including all required electronics, are 45 × 30 × 15 cm 3 . All studies can be stored as raw data and in DICOM format and are handled through a Database-Manager. The software supports a real-time viewer mode with selectable time frame and a post-processing mode, where various tools are adapted. Results The spatial resolution was measured 2 mm @0 mm, the energy resolution for the 140 keV is 26% and the maximum sensitivity of the system is 200 cps/MBq. The quantification ability was assessed using a phantom of 4 tubes filled with 99m Tc solution with different activities. Our results demonstrate accurate quantitative information even for 10 s scans. The system was tested using a mouse injected with 99m Tc-MDP for bone imaging, a mouse injected with 99m Tc-DMSA for kidneys imaging and finally a mouse injected with 99m Tc-MIBI for heart imaging. Conclusion A new low-cost system, suitable for scintigraphic mouse imaging has been developed and evaluated using phantoms and small animals. Its dimensions and cost make it a unique solution for groups activated in the field of small animal nuclear imaging.