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grids can reduce the radiation dose by a factor of 2 to 4, but with some loss of resolution. For pediatric procedures the grids can and should be removed without loss of image quality.14 Protective barriers should be readily available and used liberally. The most important of these is the lead apron. These are generally available in 0.5- and 0.25-mm thicknesses. In optimal circumstances, the 0.5-mm thickness will attenuate 98% to 99.5% of the radiation dose, whereas the 0.25-mm thickness attenuates approximately 96% of the dose.11, 15 Deterioration of the apron's lead lining occurs with use and is increased by rough handling or improper storage. Aprons should undergo periodic screening and replacement if inadequate protection is found. The protection afforded by the lead aprons in this study was less than expected and may have been due to fatigue. Alternatively, many of the aprons used were not wraparound and do not provide circumferential protection. Scattered radiation from the sides can thereby expose the underlead badge. A thyroid collar and “protective” glasses are essential. Protective eyewear is highly variable in the amount of protection afforded and allows anywhere from 3% to 98% transmission of the radioactive beam.16 The greatest protection is obtained with glasses containing lead. Some glasses may provide UV, but not ionizing radiation protection. A significant amount of the ocular exposure, up to 21%, is the result of scatter from the operator's head, which suggests that side shields or wraparound configurations are necessary to provide adequate protection.16 A lead acrylic shield, which can be either mounted on a ceiling or put on a mobile floor stand, can be placed between the operator and patient and has been shown to reduce eye radiation by a factor of 20 to 35.7, 10 Lead-lined gloves also help to reduce exposure, but can be cumbersome. Because backscattered radiation is more intense than forward-scattered radiation17 and because with the C-arm in the posteroanterior orientation the greatest exposure due to scatter occurs from under the table, we place a lead drape suspended from the operating table on the operator's side.5 The use of radiation badges by all persons working with fluoroscopy is mandatory and required by law. The position of the badges is important. A badge must be worn at waist level under the lead apron. Additional badges should also be worn on the collar to monitor the head dose and to aid in calculating the TED because there is a large and variable difference between the overlead and underlead doses.18 Ring badges are also advisable. Waist and collar badges should be worn on the operator's left side when working on the patient's right side and on the operator's right side when working on the patient's left side (ie, the badge should face the source directly). Ring badges should be worn on the hand most likely to be exposed. We monitored the left hand because it is frequently used to stabilize sheaths and is therefore close to the beam. A self-retaining device to stabilize the sheaths may also reduce exposure. The monitoring of all body positions at risk is essential because dominant hand finger doses were shown not to correlate with doses estimated by shoulder badges in interventionalists performing percutaneous drainage procedures.19 Although it is mandated, it is the responsibility of the individual to wear monitoring badges and of the institution to have a program with feedback to the exposed individuals in place. In one large prospective study of interventional radiologists Marx et al18 found that the only variable correlating with overlead collar dose was the number of procedures performed per year, and the only variable correlating with waist underlead dose was the thickness of the lead apron (0.5 mm vs 1
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