Patent ID: 7550738

Claim:
A radioisotope identification device comprising; at least one radiation detector having three dimensional event localization, said radiation detector producing event data from simultaneous interactions within said detector with gamma rays produced by at least one external radioisotope, a means to store said event data, a data set of emission gamma-ray energies characteristic of suspect radioisotopes, a means to store said data set of emission gamma-ray energies characteristic of suspect radioisotopes, a means to select a hypothetical emission gamma-ray energy for each of more than one event datum from said event data, a means to calculate backprojection cones from the event datum combined with said hypothetical emission gamma-ray energy, calculating backprojection cones for each said more than one event datum from said event datum combined with said hypothetical emission gamma-ray energy, a means to measure overlap of said calculated backprojection cones, a means to identify spatially correlated multiple overlap events, and identifying said spatially correlated multiple overlap event with presence of radioisotope.