The word “phantom” may conjure up scary ideas, like ghosts or delusions. But phantoms are also useful scientific devices. In the biomedical research community, medical imaging phantoms are objects used as stand-ins for human tissues to ensure that systems and methods for imaging the human body are operating correctly. NIST develops and disseminates phantoms as part of an ongoing effort to help ensure that medical images provide reliable and quantitative (measurable) information, not just nice pictures. Find out more about NIST's phantom work.