A mobile radiography imaging system comprising a portable radiation source adapted to move in all degrees of freedom； a portable detector operable to detect the radiation from the radiation source, wherein the detector is adapted to move independently of the radiation source in all degrees of freedom； and wherein the radiation source and the detector each includes an alignment sensor in communication with a computer； wherein the computer is in communication with the radiation source and the detector； and wherein the position and orientation of the radiation source and the detector are established by the computer, and wherein the computer sends an activation signal to the radiation source to indicate when radiation may be emitted. In a preferred embodiment, the radiation source is prevented from emission of radiation until the detector and the radiation source have achieved predetermined alignment conditions.
