We are constructing a High Resolution Tomographic Scintillation Camera System for small animal imaging. The system consists of a CsI(Tl) scintillator coupled to a military surplus image intensifier with a CCD camera focused on the output window. The system operates in photons counting mode and the spatial resolution is improved by centroid calculations for every photon interaction. The system can be mounted on an optical rail together with a pinhole collimator and a rotating table. A hot rod phantom was filled with Tl-201 or Tc-99m solute and imaged. The phantom rod diameters range from 1.1 to 1.6 mm. 64 projections were acquired (300 s/projection) with 1 mm pinhole insert. Data was reconstructed using an OSEM algorithm. Image data was corrected for decay, position non-linearities in image intensifier and the angular dependence of the pinhole. The reconstructed resolution is 13 mm (by visual inspection) for both Tc-99m and Tl-201. Higher spatial resolution is achievable with smaller pinhole diameters. Future work includes optimizing spatial resolution and sensitivity of a single system using analytical calculations, experiments and simulations. With the conclusions drawn from those calculations we plan to construct a multi-camera system.
|Conference||IEEE Nuclear Science Symposium Conference 2009|
|Period||2009/10/25 → 2009/10/31|
- Radiology, Nuclear Medicine and Medical Imaging
- single photon imaging
- small animal SPECT
- molecular imaging