Optimal Collimation Significantly Improves Lumbar Spine Radiography.

PURPOSE: To determine the influence of optimal collimation during lumbar spine radiography on radiation dose and image quality. MATERIAL AND METHODS: 110 lumbar spine patients were split into two groups-the first imaged with standard collimation and the second with optimal collimation. Body mass index, image field size, exposure conditions and dose area product were measured. Effective and absorbed organ doses were calculated. Image quality was assessed. RESULTS: Optimal collimation reduced the primary field by up to 40%. The effective dose was reduced by 48% for the AP projection, while no differences were found for the LAT projection due to incorrect positioning of the central beam with standard collimation. The absorbed dose to selected radiosensitive organs decreased by 41 and 10% in the AP and LAT projections, respectively. Image quality for the LAT projection improved by 24% and maintained for the AP projection. CONCLUSION: Optimal collimation in lumbar spine imaging significantly influences patient exposure to radiation.