THE RELATIONSHIP BETWEEN TV POSITION AND THE EFFECTIVENESS AND COMFORT OF PROTECTIVE SPECTACLES IN FLUOROSCOPIC PROCEDURES

Although interventional radiological procedures can result in signific ant eye doses to an operator, protective measures are often rejected b ecause screens are found to impede manipulations, and 0.5 mm lead equi valent spectacles are heavy and uncomfortable. With many units the TV monitors are positioned so that the operator needs to turn his head th rough 80 degrees or more to view the image while screening. The aim of this study was to determine the distribution of the shielding in prot ective spectacles which will combine maximum dose reduction for differ ent TV positions with minimum weight. Thermoluminescent dosimeters wer e used to assess the effectiveness of various spectacles in shielding the lens of the eye when a skull phantom was orientated at different a ngles in a large area beam of X-rays generated at a tube potential typ ical of diagnostic energies. The beam was tilted upwards at an angle o f 20 degrees as though originating from the irradiated volume of a pat ient. The results showed that if weight was a consideration, and the h ead was turned away from the image intensifier through an angle greate r than 80 degrees, the shielding was most effective when concentrated in the side-panels of the spectacles. The shape of the side-panels, ho wever, was critical to the adequate shielding of this radiation.