An imaging apparatus, comprising: a substantially O-shaped gantry ring having a central opening for positioning around an object to be imaged, the gantry ring having interior sidewalls extending 360 degrees around the central opening and defining an interior cavity that extends 360 degrees around the interior of the gantry ring; a motorized rotor housed within the interior cavity of the gantry ring and rotatable 360 degrees around the central opening; a source moveably secured to the rotor, wherein the source is adapted to project a beam of radiation along a first trajectory; a detector moveably secured to the rotor, and positioned to receive the beam of radiation along the first trajectory; a detector positioner that translates the detector from a first detector position to a second detector position on the rotor in a direction that is substantially normal to the first trajectory, wherein the detector positioner comprises: a positioner frame having a base and two parallel side walls with flat top surface, a detector carriage for holding the detector and with which the detector is translated to the second position within the frame on the rotor, a motor to power translation of the detector carriage, brackets connected to the detector carriage to which the motor is mounted, a friction wheel is biased against the flat top surface of each wall of the frame; and a beam positioner that alters the trajectory of the radiation beam to direct the beam onto the detector located at the second position, wherein the beam positioner includes a tilting beam positioning mechanism that includes a frame that houses the source and a motorized system connected to both the frame and the source; the apparatus being arranged to rotate the rotor to a plurality of select rotational positions around and within the interior cavity of the gantry ring, and to synchronize the trajectory of the radiation beam with the translational position of the detector, so as to obtain effectively large field-of-view object images based on images at the first detector position and the second detector position from a plurality of projection angles over a partial or full 360 degree rotation of the rotor; wherein the source is tiltable by the beam positioner at each selected rotational position of the plurality of selected rotational positions and the detector is translateable with the detector positioner at each selected rotational position of the plurality of selected rotational positions. a substantially O-shaped gantry ring having a central opening for positioning around an object to be imaged, the gantry ring having interior sidewalls extending 360 degrees around the central opening and defining an interior cavity that extends 360 degrees around the interior of the gantry ring; a motorized rotor housed within the interior cavity of the gantry ring and rotatable 360 degrees around the central opening; a source moveably secured to the rotor, wherein the source is adapted to project a beam of radiation along a first trajectory; a detector moveably secured to the rotor, and positioned to receive the beam of radiation along the first trajectory; a detector positioner that translates the detector from a first detector position to a second detector position on the rotor in a direction that is substantially normal to the first trajectory, wherein the detector positioner comprises: a positioner frame having a base and two parallel side walls with flat top surface, a detector carriage for holding the detector and with which the detector is translated to the second position within the frame on the rotor, a motor to power translation of the detector carriage, brackets connected to the detector carriage to which the motor is mounted, a friction wheel is biased against the flat top surface of each wall of the frame; and a positioner frame having a base and two parallel side walls with flat top surface, a detector carriage for holding the detector and with which the detector is translated to the second position within the frame on the rotor, a motor to power translation of the detector carriage, brackets connected to the detector carriage to which the motor is mounted, a friction wheel is biased against the flat top surface of each wall of the frame; and a beam positioner that alters the trajectory of the radiation beam to direct the beam onto the detector located at the second position, wherein the beam positioner includes a tilting beam positioning mechanism that includes a frame that houses the source and a motorized system connected to both the frame and the source; the apparatus being arranged to rotate the rotor to a plurality of select rotational positions around and within the interior cavity of the gantry ring, and to synchronize the trajectory of the radiation beam with the translational position of the detector, so as to obtain effectively large field-of-view object images based on images at the first detector position and the second detector position from a plurality of projection angles over a partial or full 360 degree rotation of the rotor; wherein the source is tiltable by the beam positioner at each selected rotational position of the plurality of selected rotational positions and the detector is translateable with the detector positioner at each selected rotational position of the plurality of selected rotational positions.