Abstract: Apparatus and methods are described for use with an X-ray system including an X-ray anti-scatter grid that includes at least a first layer of elongate radiopaque septa arranged such that longitudinal axes of each the septa belonging to the first layer are disposed along a first direction, in parallel to each other. Spaces between the septa are filled with air, and a rigid frame supports the septa. Two or more slotted plates are coupled to the rigid frame, each of the slotted plates defining a plurality of slots, each of the septa passing through a respective pair of slots defined by a pair of the slotted plates disposed on opposite sides of the frame from each other, such that the orientation of each of the septa with respect to the frame is determined by the orientation of the corresponding pair of slots with respect to the frame.