[Investigation of Factors Related to Operator's Eye Lens Doses during Cardiac Catheterization Using a Specially Made Acrylic Phantom].

Abstract

Purpose: We investigated the factors that influence the eye lens dose to the operator during cardiac catheterization using a cylindrical acrylic phantom, which can place small dosimeters at 3-mm depth from the surface.

Methods: A cylindrical acrylic phantom was placed on top of the thoracic phantom, which was used as the operator's phantom. The absorbed doses at the assumed positions of the eye lenses of the operator's phantom were measured by two irradiation modes. It was integrated from two projections in fluoroscopy mode. In cine mode, it was integrated from 15 projections. The measurement was performed by changing height of eye lenses (150, 165, and 180 cm), orientation of the cylindrical phantom (0°, 15°, 30°, and 45°), and the position of the operator's phantom (radial access, femoral access, and the position of the second operator).

Results: The lens doses decreased as the phantom height increased. The doses at the left neck were 1.2 to 1.4 times higher than those at the eye lens. The lens doses tended to decrease as the cylindrical phantom was oriented away from the X-ray tube, and it was the highest when the phantom was at the radial access approach position.

Conclusions: During cardiac catheterization, the absorbed dose of the operator's lens depends on the operator's height, head orientation, and position. If the dosimeter is placed on the neck, the eye lens dose can be conservatively estimated.