The Ludlum Fluoroscopic Beam Alignment device consists of an aluminum plate with four sliding brass strips set in recessed channels. The strips define the border or visible area of the image receptor. A plastic overlay prevents any vertical displacement of the brass strips. Holes drilled in half-inch intervals are filled with higher density material for visibility through the brass strips. The device, when placed in the center of the image receptor, is designed to correct or optimize fluoroscopic collimation.
Any portion of the fluoroscopic field that falls outside the image receptor does not contribute to a useful image and can lead to unnecessary exposure to the patient. This very simple but critical measurement will identify a misaligned fluoroscopic system.