Systems and methods are described herein for performing three-dimensional imaging using backscattered photons generated from a positron-electron annihilation. The systems and methods are implemented using the pair of photons created from a positron-electron annihilation. The trajectory and emission time of one of the photons is detected near the annihilation event. Using this collected data, the trajectory of the second photon can be determined. The second photon is used as a probe photon and is directed towards a target for imaging. The interaction of the second probe photon with the target produces back scattered photons that can be detected and used to create a three-dimensional image of the target. The systems and methods described herein are particularly advantageous because they permit imaging with a system from a single side of the target, as opposed to requiring imaging equipment on both sides of the target.