RESUMEN
Background and Objective: Computed Tomography of brain (CT brain) is a higher radiation dose imaging technique than in the conventional radiographic examination. Not only the brain but also the orbits may included in the area of scanning. The radiation risk of CT brain to patient was the effect of radiation damage to the lens of eye which is the radiosensitive organ. Which may induced cataracts. In 2005, the Multislice CT was set up in Sappasittiprasong hospital Ubonrajchathani. The majority of CT examination was CT brain. There is no previous study to determine the radiation dose delivered to the eye of the lens. The result of scattered radiation dosimetry may provide to evaluate of radiation risk to the patient. This study aim to measure the scattered radiation dose to the lens of the eyes in Rado Phantom during scanning CT brain.Method : An experimental study was performed at Physics Department, Faculty of Science, Ubonrajchathani University and Sappasit-tiprasong hospital Ubonrajchathani. Using the thermoluminescence dosimeter (TLD). The TLD discs model TLD–100 and TLD Reader in model 3500 provided by Harshaw. The TLD–100 discs were attached directly to both eye of Head rando phantom and they were scanned to measure the scattered radiation dose to the lens during procedures. The protocol for brain examination was 120 kV 250 mAs. Result: The mean scattered radiation dose to lens of head rado phantom was 13.87 mGy .Conclusion: The measured dose was lower than the reported threshold of lens opacity and well cataract. Keywords: Scattered Radiation Dose, Computed Tomography of brain, lens dose, thermoluminescence dosimeter (TLD)