Any imaging technology applied in biology can be referred to as biological imaging. In fields including molecular biology, medical imaging, computer technology, and computational approaches, we've seen tremendous progress in the last decade. Revolutionary improvements are being produced at the interface between these fields, despite the fact that advances in each field have brought exciting new insights and possibilities. The field of molecular imaging has grown fast at the intersection of molecular biology, medical imaging, and computer technology. The purpose of this new field is to gain a better knowledge of biological processes by imaging cellular and molecular events in both normal and diseased processes in animal-model systems and humans. Novel combinations of molecular and cellular biology with state-of-the-art imaging technologies that enable measurements of biological processes at the cellular and molecular level are enabling advancements in this field.