Evaluation and verification of a simplified lead equivalency measurement method

Area of Science:

• Medical Imaging
• Radiation Protection
• Radiography Equipment

Background:

• Ensuring adequate lead equivalency in radiation protection apparel is crucial for patient and staff safety.
• Traditional methods for verifying lead equivalency can be costly and time-consuming.
• Digital radiography (DR) systems offer potential for novel quality assurance methods.

Purpose of the Study:

• To present an inexpensive tool and method for determining lead equivalency using digital radiography (DR) x-ray equipment.
• To validate the accuracy of the developed tool and method against known lead thicknesses and manufacturer specifications.
• To assess the lead equivalency of common radiation protection apparel.

Main Methods:

• A test tool was fabricated using lead foil tape with nine varying thicknesses (0.1-1.0 mm).
• The tool was imaged using a DR plate and portable x-ray unit across various energies (60-120 kVp) and beam filtrations.
• Lead equivalency was calculated by correlating detector dose with pixel values, with validation against caliper measurements and apparel manufacturer data.

Main Results:

• The developed method demonstrated a measurement difference of -9.7% to 7.1% for known lead thicknesses across different energy and filtration conditions.
• Measurements of protective eyewear, thyroid shields, and lead aprons showed a range of -6% to 20% compared to manufacturer values.
• The accuracy was consistent across various energies and beam filtrations, including a 1-mm copper filtered beam.

Conclusions:

• The developed tool and methodology provide an inexpensive and effective alternative for checking lead equivalency in clinical settings.
• This approach is largely equipment-independent, requiring only basic prerequisites for implementation.
• The findings support the routine use of this method for quality assurance of radiation protection materials.