慢性血栓塞栓性肺高血圧症に対するバルーン肺動脈拡張術における術者と医療スタッフの被ばく低減法

The purpose of this study is to investigate a reduction method of radiation exposure for operator and medical staff in balloon pulmonary angioplasty (BPA) for chronic thromboembolic pulmonary hypertension (CTEPH). We devised a new radiation protection, which is U-shaped acrylic supporting table with 0.35 mmPb unleaded radiation protection sheet. A human phantom was put on the bed of cardiac angiography system [C-arm angulation: posteroanterior (PA), L-arm angulation: left anterior oblique (LAO) 60°]. The ambient equivalent dose rate was measured under fluoroscopy with and without three radiation protections: U-shaped acrylic supporting table with 0.35 mmPb unleaded radiation protection sheet, radiation protection for the lower body, and radiation protection for the upper body. With the three radiation protections, the ambient equivalent dose rate was decreased more than 99% at the height of 100 cm above the floor at the operator position (PA: from 186.2 μSv/h to 0.5 μSv/h, LAO 60°: from 350.4 μSv/h to 1.6 μSv/h). Ambient equivalent dose rate at the other points are also decreased effectively. The devised dose reduction method can reduce operator and medical staff radiation exposure effectively and be set up without interference for BPA procedure.