Lead Apron Inspection
X-ray Aprons - Inspect to Protect!
The workhorse of the radiology department, your x-ray apron is often the only line of defense between you and the harmful radiation you encounter on a daily basis. Routine inspection of your apron is critical – but there are differing opinions as to the testing frequency, inspection methods and criteria used to reject lead aprons.
In this article, we’ll explore some inspection standards employed throughout the industry to ensure your safety and that of your patients.
What are the requirements for lead apron inspection?
Testing lead aprons is a requirement of state x-ray boards and other health care regulatory organizations such as The Joint Commission. As far as we are aware, there is no specific regulatory or state standard that outlines how lead apron testing should be performed, ONLY that testing and inspections should be performed.
Typically, facilities develop their own policies and procedures to evaluate their lead aprons. Many facilities perform an inspection of each apron on an annual basis. Some facilities choose to survey their aprons on a more frequent basis, such as every six months, especially if the aprons are heavily used.
What should the inspection method be?
To ensure a thorough inspection, the following types of inspections are recommended:
- Visual (looking at the apron)
- Tactile (feeling the apron for holes)
- Fluoroscopy or x-ray
Some regulatory bodies require that aprons be x-rayed, while others say that a combination of visual and tactile inspection is sufficient. However, x-ray/fluoroscopy inspection can reveal issues such as lead rot (the lead inside the apron reacts with ascetic acid and carbon dioxide, until only lead carbonate powder is left) or vampire marks (usually caused by clipping ball point pens to the apron collar area, among other things).
Here's a rundown as to how to employ the different inspection methods:
Visual Inspection - lay the apron out on a clean, flat surface and visually inspect for any tears, perforations or imperfections (such as bumps) that may warrant further inspection. Take note of the apron closures (velcro, buckles, etc.) to ensure that they are in proper working order.
Tactile Inspection - run your hands over the entire surface of the apron to find any thinning of the lead or creases. You can lay the apron down or hang it on an apron rack and place one hand on the front and one hand directly on the back of the apron. Keeping your hands directly parallel to each other, slowly run both hands up and down the surface area of the apron, noting anywhere there is a thinning or creasing of the material.
X-ray Inspection - While typically not an issue at hospitals, fluoroscopic equipment might not be available at smaller clinics, so the x-ray method is a suitable alternative.
- Closely inspect each item for kinks and irregularities.
- Take a radiograph of suspect areas.
- Process the image and look for breaks in the lead lining, typically appearing as dark slashes.
Fluoroscopy Inspection - A fluoroscopic examination may uncover some defects overlooked in a physical inspection. However, the disadvantage is the additional time to perform the fluoroscopic procedures, as well as the additional radiation dose to the inspector.
- Lay out the item on the table.
- Examine the entire item using the fluoroscope’s manual settings and low technique factors (e.g. 80 kvp).
- Shielded areas will appear dark and defects, seams, and stitching will appear light.
Note: Do not use automatic brightness control, as this will drive the tube current and high voltage up, resulting in unnecessary radiation exposure to personnel and wear on the tube.
How do I know when an apron passes/fails inspection?
While there are no government guidelines in place to evaluate whether an apron passes or fails an inspection, there are some industry norms. Many states, hospitals and research organizations use the widely cited article entitled "Inspection of Lead Aprons: A Practical Rejection Model" of Drs. Pillay and Stam (Health Physics, volume 95, No. 2, August 2008). This article gives criteria to aid in determining when x-ray aprons should be discarded, such as:
Tearing
For a single apron with a 0.50 lead/lead equivalency, tears of more than 5.4 cm in length are cause for rejection. Smaller perforations or cracks in the edges can result in rejection as well, depending on the length and width of the apron as compared to the size of the defect. Taking an x-ray of the apron is often the only way to detect smaller breaks or cracks along the sides.
Thinning
Thinning of the lead and the outer protective layer of the apron also warrants rejection. Thinning is the result of prolonged use, and creates a floppy, comparatively lightweight apron that can expose the patient or health care worker to lead. Thinning is determined by measuring thickness in relation to the size of the apron.
Defective Velcro, Buckles or Ties
Irreparably broken apron closures warrant an inspection failure. Each lead apron is designed to protect different areas of the body. For example, an apron used at a dentist's office is high around the neck to ensure complete coverage of the thyroid gland. Broken Velcro or other closure mechanisms will cause the unsecured apron to slide downward, exposing the gland to harmful x-rays, and is therefore not acceptable.
Defects in relation to placement
Defects near certain organs would cause an apron to be rejected: 1.7 cm tear over the gonads, 1.8 cm tear over the thyroid, etc. These values are for a single apron comprised of .5 mm lead (or lead equivalent).
Keeping track of inspections
Just as important as it is to inspect the aprons is to keep record of the inspections. Many facilities include inspection labels on each apron, which includes the dates of inspection. A summary of the inspections are typically kept in some electronic format (such as Microsoft Excel).
Larger facilities, with many departments that have their own aprons, are turning to software designed specifically to keep track of the inspections. Aprons are “tagged” with buttons containing unique id numbers, while the software keeps track of not only the apron inspection status, but also keeps track of apron inventory.
***Whatever method of inspection and rejection criteria you use, avoid premature damage to your apron by taking care of it. Proper storage is important to maintain the integrity of the lead and Cone Instruments offers a variety of lead apron racks to suit your department’s storage needs and budget. When it is time to replace your radiation protection - we offer a full line of x-ray aprons, radiation protective gloves, lead glasses, radiation barriers and more.
***************Sources:
Pillay, M. Stam W. Inspection of Lead Aprons: A Practical Rejection Model; Health Physics, volume 95, No. 2, August 2008
Lambert, K. McKeon, T. Inspection of Lead Aprons: Criteria for Rejection; Operational Radiation Safety, May 2001
The Use and Care of Lead Protective Equipment; www.ncradiation.net, July 2009
D. Lofton, S. Kovari; Shielding International
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