Use of leaded garments substantially reduces radiation exposure by protecting specific body regions. Many fluoroscopy users would exceed regulatory limits should lead aprons not be worn. Operator and nearby staff (within 2 meters) are required to wear lead aprons whenever fluoroscopes are operated at Henry Ford Hospital. Due to the poor material qualities of Leaded garments, proper storage is essential to protect against damage (Figure 5-6). Whenever leaded apron are required, they must be supplied and paid for by your employer (Henry Ford Health System)
Figure 5-6: Properly Stored Leaded Garments
Courtesy of Sorenson, 2000.
Courtesy of Sorenson, 2000.
Lead aprons do not stop all the x-rays. Typically at least a 80% reduction in radiation exposure is obtained by wearing a lead apron (Figure 5-7). It should be noted that the apron's effectiveness is reduced when more penetrating radiation is employed (e.g., the ABC boost's kVp for thick patients). Two piece lead apron systems are recommended for most users since they provide "wrap-around protection" and distribute weight more evenly on the user. Some aprons contain an internal frame that distributes some of the weight from the shoulders onto the hips much like a backpack frame. So called "light" aprons should be scrutinized to ensure that adequate levels of shielding are provided. State of Michigan law requires the use of 0.5 mm lead equivalent aprons.
Courtesy of Sorenson, 2000.
Lead aprons do not stop all the x-rays. Typically at least a 80% reduction in radiation exposure is obtained by wearing a lead apron (Figure 5-7). It should be noted that the apron's effectiveness is reduced when more penetrating radiation is employed (e.g., the ABC boost's kVp for thick patients). Two piece lead apron systems are recommended for most users since they provide "wrap-around protection" and distribute weight more evenly on the user. Some aprons contain an internal frame that distributes some of the weight from the shoulders onto the hips much like a backpack frame. So called "light" aprons should be scrutinized to ensure that adequate levels of shielding are provided. State of Michigan law requires the use of 0.5 mm lead equivalent aprons.
Figure 5-7: Lead Apron Protection Efficiency
Courtesy of Sorenson, 2000.
Note that higher tube voltages sharply reduces the shielding benefits of lead aprons. Higher tube voltages will occur when imaging large patients or thick body portions. Also note that light aprons (0.25 to 0.35 mm Pb) provide less protection compared to the recommended 0.5 mm thickness.
Thyroid shields provide similar levels of protection to the individual’s neck region. Thyroid shield use is required for operators who use fluoroscopy extensively during their practice.
Optically clear lead glasses are available that can reduce the operator's eye exposure by 85-90% (Siefert 1996). However, due to the relatively high threshold for cataract development, leaded glasses are only recommended for personnel with very high fluoroscopy work loads (e.g., busy Radiology and Cardiology Interventionists). Glasses selected should be "wrap-around" in design to protect the eye lens from side angle exposures. Leaded glasses also provide the additional benefit of providing splash protection. Progressive style lenses for bifocal prescriptions are available from a limited number of manufacturers.
The latex leaded gloves provide extremely limited protection. Standard (0.5 mm lead equivalent) leaded gloves provide useful protection to the user’s hands. However, trade-offs associated with use of 0.5 mm leaded gloves include loss in tactile feel, increased encumbrance and sterility. For these reasons, use of leaded gloves is left to the operator’s discretion. To minimize radiation exposure to the hands, the operator should:
Note that higher tube voltages sharply reduces the shielding benefits of lead aprons. Higher tube voltages will occur when imaging large patients or thick body portions. Also note that light aprons (0.25 to 0.35 mm Pb) provide less protection compared to the recommended 0.5 mm thickness.
Thyroid shields provide similar levels of protection to the individual’s neck region. Thyroid shield use is required for operators who use fluoroscopy extensively during their practice.
Optically clear lead glasses are available that can reduce the operator's eye exposure by 85-90% (Siefert 1996). However, due to the relatively high threshold for cataract development, leaded glasses are only recommended for personnel with very high fluoroscopy work loads (e.g., busy Radiology and Cardiology Interventionists). Glasses selected should be "wrap-around" in design to protect the eye lens from side angle exposures. Leaded glasses also provide the additional benefit of providing splash protection. Progressive style lenses for bifocal prescriptions are available from a limited number of manufacturers.
The latex leaded gloves provide extremely limited protection. Standard (0.5 mm lead equivalent) leaded gloves provide useful protection to the user’s hands. However, trade-offs associated with use of 0.5 mm leaded gloves include loss in tactile feel, increased encumbrance and sterility. For these reasons, use of leaded gloves is left to the operator’s discretion. To minimize radiation exposure to the hands, the operator should:
- Avoid placing his hands in the primary beam at all times;
- Place hands only on top of the patient. Hands should never be placed underneath the patient or table top during imaging;
- Consider using leaded gloves if hand placement within the X-ray beam is necessary or positioned nearby for extended periods of time.
No comments:
Post a Comment