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Radiation dose limits in the controlled area of an X-ray room have been prescribed at 1.3 mSv/3 months by the Enforcement Regulations of the Medical Service Law. Leakage effective dose must be measured once within a period that does not exceed six months. Scattered radiation and leakage effective dose were measured in 4 X-ray rooms (chest X-ray room, general-purpose X-ray room, skull and neck X-ray room, and X-ray CT room) with the optically stimulated luminescence dosimeter (OSLD), which is a passive integrating dosimeter. The availability of the measurement method for radiation control with OSLD was evaluated. Scattered radiation in the inside wall surface of the skull and neck X-ray room was less than 1.3 mSv/3 months of the dose limits. There was more scattered radiation in the X-ray CT room than in other X-ray rooms, and the maximum dose was 428 mSv/3 months, measured on the floor. All measurements of leakage effective dose in the 4 X-ray rooms were less than the radiation dose limit, and most measurements of leakage effective dose were less than the detection limits of the dosimeter. Leakage effective dose as calculated by Law 188 (Law 188-Dose) was less than the radiation dose limits in three X-ray rooms, the exception being the X-ray CT room. The Law 188-Dose of the X-ray CT room exceeded 1.3 mSv/3 months at the walls where primary X-rays were directed. The measurement method of leakage effective dose with an ionization survey meter was not able to guarantee the workload of each X-ray apparatus. Therefore, we were not able to confirm the security of X-ray rooms by measurement with an ionization survey meter. Scattered radiation in X-ray rooms was generated intermittently and showed a low dose rate. Consequently, it was established that dose leakage from X-ray rooms must be measured with an integrating dosimeter. It was suggested that the measurement method of environmental dose with OSLD was useful to measurement for radiation control.

The management of patient dose has become more of an issue in recent years. Dose can be determined non-invasively and in real time through the use of a dose area product meter, but it is the area dose value that is obtained. Therefore, we created a program that estimates entrance skin dose (ESD) in real time from area dose values obtained during procedures. We used Microsoft Visual C++ 6.0 (Standard Edition) for the programming language and C language for the programming environment. The value was a maximum 285.4 mGy at ileus tube insertion when measuring ESD for radiography of the digestive organ and non-vascular type IVR using the created program and seeking the average according to the procedures. The program that we created can be considered valid for monitoring ESD correctly and in real time.

A study was performed to evaluate operator dose during diagnostic and interventional radiology procedures (IVR) and to establish methods of operator dose reduction with a radiation protective device. Operator dose was measured by glass dosimeters worn on the neck and on the abdomen outside the lead apron. In addition, the dose of the primary beam at the collimator surface was measured, which made it possible to define the correlation between the entrance air kerma, measured with Skin Dose Monitor, and operator dose exposed during the monitored procedure. IVR protectors were developed to decrease the amount of scatter radiation received by operators performing the procedures, and their effects were evaluated in abdominal and cardiac angiography procedures. The average effective dose and doses of the neck and abdomen outside the lead apron, estimated for individual procedures, were as follows: abdominal angiography procedures: effective dose, 0.07 mSv; neck area, 0.18 mSv; abdominal area, 0.51 mSv; cardiac angiography procedures: effective dose, 0.07 mSv; neck area, 0.13 mSv; abdominal area, 0.68 mSv. Operator doses were well correlated with exposure dose in abdominal angiography procedures (diagnostic procedure r=0.84, IVR r=0.77). It was found that 68.0% of the effective dose in abdominal angiography procedures and 43.0% of the effective dose in cardiac angiography procedures could be reduced by the use of IVR protectors. Operator and patient doses in interventional radiology were interdependent. The minimization of operator doses is particularly important during interventional radiology, and it is necessary to be aware of practical radiation protection procedures. Measures that reduce patient dose will also reduce occupational exposure. Moreover, operator dose could be substantially reduced by the use of IVR protectors in addition to wearing a protective lead apron during IVR. It was suggested that IVR protectors are effective radiation protective devices in interventional radiology procedures.