High resolution gamma ray detectors for positron emission tomography (pet) and single photon emission computed tomography (spect)

摘要

A device and method for detecting gamma rays in a diagnostic imaging system preferably utilizing fast step index scintillating fibers and photomultipliers is provided by the present invention. A plurality of scintillating fibers are formed into layers comprising substantially parallel fibers positioned lengthwise each other in each layer. Each layer is positioned parallel each adjacent layer with each layer having its respective fibers at an angle of substantially either 60 DEG or 90 DEG to each adjacent layer. Preferably, position sensitive photomultipliers are provided and each photomultiplier is coupled to a plurality of fibers and each fiber has at least one end coupled to a photomultiplier. Data output from each photomultiplier is collected and processed to determine spatial coordinates of the origination position of a detected gamma ray. The present invention provides a high resolution gamma ray detector having an improved signal-to-noise ratio. This improves significantly the diagnostic power of the presently used PET and SPECT systems, and greatly extends the field of their application both in medical diagnosis and research. In addition, the present invention enables use of longer-lived positron emitting radioactive isotopes than presently used in typical PET systems.