DESIGNING A STRATIFIED DETECTION SYSTEM FOR PET CAMERAS.

The design of a staggered-exponential-multistrata (SEMS) detection system is presented. This design replaces the conventional detector ring with multiple staggered layers of detector rings. The thickness of the layers increases exponentially. The SEMS design can improve the spatial resolution, allowing the detector ring to be smaller, and can obviate the need for detector wobbling. The improvement is particularly significant in high-resolution PETs and PETs designed for small objects such as the brain, animals, limbs, and infants. Image resolution approaching the theoretical limit of positron range can be achieved for the entire field of view (FOV), rather than just at the center of the FOV as in the conventional design. The reduction in detector ring size increases the sensitivity and lowers the cost of both the gantry and detection system. The elimination of detector motion simplifies the gantry mechanics and cost. In addition, the image artifact resulting from the frequency beating of the heart cycle and detector wobbling cycle are also eliminated. The high resolution, high sensitivity, compactness, and low cost make this design suitable for research.