On the Safe Use of Portable Intraoral X-ray Units in Large-Scale Disasters

Objective: The needs of intraoral radiography are increasing for home care and especially for victim identification after the Great East Japan Earthquake. In this study, we evaluated the characteristics of output X-rays and measured air kermas of stray radiation from three battery-powered portable intraoral X-ray units.Materials and Methods: The air kermas of stray radiation, generated from an IEC CT dosimetry head phantom and the X-ray units, which included DEXICO ADX4000, DEXICO ADX4000W, and DEXICO DX3000 （10DR Japan）, were measured using Pitman 37D and the 350cc ionization chamber attached （Pitman）.Results: If an operator works in a sectioned area with a central angle of 180±60 degrees and a radius of 0.5m, the mean stray radiation was 0.353μGy for the ADX4000, 0.297μGy for the ADX4000W, and 0.288μGy for the DX3000 per 1mGy at the cone tip of each unit.Discussion: In the event of a large-scale disaster, an operator would be taking many radiographs for victim identification each day. Therefore, this can be done by setting up a control area that ensures a sufficient distance from the radiation source, wearing a lead apron and using a protection board.