Systems and methods for x-ray imaging are disclosed, particularly non-rotating, stationary gantry and mobile x-ray computed tomography systems and methods for imaging a subject, and particularly for imaging the head, spine, and neck of a subject. Compared to rotating-gantry computed tomography scanners, non-rotating stationary gantry x-ray computed tomography scanners are more mobile and transportable. Non-rotating stationary gantry x-ray computed tomography scanners can thus be used in mobile transport units and in-field applications.