血管撮影領域における術者に対する放射線防護

Abstract

Purpose : To estimate scattered dose rates from phantom measurements during interventional radiology(IVR)and to establish methods to reduce the angiographer's exposure in IVR. Materials and methods : Scattered dose rates were measured in lines parallel in space to the central ray of the x-ray beam, at lateral distances of 50 cm. They were measured by the ionization chamber dosimeter, which was made to have directivity by a lead slit. New radiation protective devices for angiographers were developed and their effects evaluated. Results : The scattered dose rates to which the angiographer was exposed during IVR were scattered from a collimator and a patient. The abdominal area was almost completely exposed by the scattered dose from the patient. The head and neck area were exposed by the commensurate scattered dose from the collimator and the patient. The scatter exposure rates of the abdominal area were reduced to 5-20% by a lead curtain attached beneath the tissue table and a lead barrier next to the patient's trunk. And the scattered dose rates of the head and neck area were reduced to 50-70% by shielding a surface of the tissue table between the angiographer and the patient. Conclusion : To reduce exposure of the head and neck area, it is necessary to shield the surface of the tissue table between the angiographer and the patient. To reduce exposure of the abdominal area, it is necessary to shield beneath the tissue table and next to the patient's trunk. The new radiation protective devices were considered very useful and effective in reducing the angiographer's exposure rates.