Image information processing using optical cameras guarantees information accuracy in images based on geometrical optical principle. On the other hand, nuclear gamma rays are the same electromagnetic waves as light, but because they behave as quantum due to high energy, reflection and refraction can not be used, that making imaging difficult. Although gamma ray cameras based on the incomplete reconstruction of Compton process such as conventional Compton Cameras have been studied, there has been realized no one focusing gamma-rays to one point like the optical camera. Therefore, we now could utilize only image information with low accuracy . This ETCC has established and put into practical use a technique for completely measuring the reaction of gamma rays with matter (Compton scattering) and gathering gamma rays to one point in computer like optical camera. By this technique, image processing equivalent to image information processing of light was realized with nuclear gamma rays.
