In portable radiography, image quality is degraded by scattered radiation. Use of an accurately aligned, antiscatter grid can provide consistently high image quality, but the necessary precision for grid alignment is difficult to achieve with conventional techniques. The authors developed a simple laser alignment method for bedside radiography. A compact laser device is mounted on the collimator housing of a mobile radiography machine, so that the laser beam is precisely parallel to the central x-ray beam. A small reflector device, which attaches to the edge of the grid cassette, indicates beam centering and alignment in a clear, intuitive way. In clinical use, the laser alignment technique provided uniformly high image quality, equivalent to that of fixed equipment. The system has the advantages of being simple to use and inexpensive to implement with existing equipment.
