As represented by conventional radiograph, radiological images provide only black and white figures in 2D space. The situation is basically the same for Single photon emission tomography (SPECT) and positron emission tomography (PET), which are the two most common molecular imaging techniques used in nuclear medicine. PET is used especially for early cancer and Alzheimer’s disease detection, but radioactive tracers suitable for each detector are limited in terms of energy. For example, PET can only image monochromatic gamma rays thus provide black and white 2D images. Moreover, production of PET tracers, usually made by a cyclotron facility in medical centers, is inevitably costly.