Application of liquid scintillation light guide (LSLG) to scattered X-ray measurement from dental panoramic radiography system.

A 1.2 m flexible liquid scintillation light guide (LSLG) detector connected to a portable electric device was developed and applied to monitor X-rays scattered from a panoramic dental X-ray imaging apparatus. The X-ray absorption of the LSLG tube was simulated for 20 and 40 keV X-rays. The LSLG detector was calibrated by comparing doses measured by a 3-inch NaI(Tl) detector using Am-241 and Cs-137 sources. A linear relationship was obtained between dose rates (μSv/h) and count rates (cps). The elapsed time profile of scattered radiation from a panoramic dental X-ray imaging apparatus was determined. Local absorbed doses were measured with small OSL dosimeters on the LSLG tube suspended over the shoulder and the eyeglass. Behind the ears and neck (in the center of the LSLG tube) showed high doses. The LSLG detector was useful for real-time monitoring of scattered X-rays.