Physics and optics of a new gamma camera design

Gamma camera technology has evolved during the past two or three decades and is now a mature product. This paper will show that important gains can still be made at the detection level by modifying some optical components and by considering a new description of the physical phenomena. The first design modification to the detector would be to match the indices of all optical materials, from the crystal to the photomultiplier tube's window. The second and equally important point where improvement is possible is in the elimination of the spatial/spectral distortions. We will show that a complete description of the scintillation process is only possible when taking into account the depth-of-interaction (DOI) of the gamma in the crystal. Finally, the spectral contamination caused by gamma rays undergoing Compton interaction either in the object or in the detector itself is addressed by the Holospectral imaging technique. In this approach, events from the whole spectrum are accepted (as opposed to the energy windowing presently in use) and formatted into a series of energy frames. Statistical analysis is then performed on these multidimensional data to segregate object-related variance and contamination.