Organ and effective doses were evaluated for various head x-ray radiography and head CT examinations based on in-phantom dose measurements with photoluminescent glass and photodiode dosimeters. Brain doses were ranged between 0.46 and 1.08 mGy, in five different type of head radiography. Lens doses were the highest in the case where x-ray directly hit lens (e.g. head AP and Towne radiography) . The effective doses were in a range of 0.03-0.06 mSv. The effective dose for routine head CT examination was found to be 1.7 mSv, which was more than 50 times higher than that of head AP radiography. The maximum skin dose was as high as 712.0 mGy, in CT perfusion used in the diagnosis of acute brain infarction. The value, however, was lower than the threshold of 3 Gy (recommended value by the ICRP Publ. 59) for hair loss. Lens doses of 55.0 mGy for routine head CT examination and of 39.6 mGy for CT perfusion were also lower than the threshold value of 0.5 - 2.0 Gy (recommended value by ICRP Publ. 60) for clouded lens.
We developed the on-line radiation teaching materials using the Internet, in order to provide the teaching support materials of atomic power and radiation educations in onschool study, as well as to create the complementary study system in off-school study. The themes of teaching materials were selected from requests by teachers. In the case of an elementary school, the teaching material“an environmental problem and atomic power”was created as the aggregate of each content for study without boundary between subjects. The teaching material “medical treatment and radiation”was created for junior high school students to raise the individual knowledge. In the case of a high school, the teaching material“nucleus and radiation”was prepared to supplement the physical study of students. The on-line teaching materials were tried to 300 junior high school and high school students, 68% of students answered that the teaching material is effective to understand atomic power and radiation, though 17% answered they were not effective. Although there are problems to prepare IT learning equipments and learning follow-up system in the material, it is suggested that the on-line teaching materials will provide the novel learning system including debates for the study. This method has no limitation of time and place.