An adjustable mount for positioning an x-ray source comprising a vertical member that can swivel around a yaw axis, a circular arc-shaped yoke having two ends and passing through the vertical member, a gantry attached to the two ends of the yoke, and an x-ray source attached to the gantry. The x-ray source can be rotated around the yaw axis by swiveling the vertical member, pitched around a pitch axis by pitching the gantry, and/or rotated around a roll axis by passing the yoke through the vertical member. A method for x-ray imaging that includes centering an x-ray source at an aiming position within an adjustable mount, and aiming the centered x-ray source at an x-ray sensor by rotating the x-ray source around a roll axis of the adjustable mount. An x-ray source mounting system comprising an x-ray source and an adjustable mount to which the x-ray source is attached.