A cubic gamma camera with an active collimator.

Mechanical collimation with photon absorption and electronic collimation using Compton scattering are combined to form a cubic gamma camera with an active collimator. The collimator is made active by constructing it with a uniformly redundant array of patterned Bi4Ge3O12 (BGO) scintillators, which not only attenuates incident radiations but also detects scattered radiation, in a gamma-camera consisting of and five planar CsI(Na) scintillators. The entire module forms a cubic structure that generates images on the basis of radiation interactions from every direction. The coverage angle for detecting scattered radiation is 2π with a detection efficiency approximately 17 times higher than previous systems that comprised only one pair of detectors.