Author: Nicholas Borges, Steven Brown, Jerimy C. Polf 👨🔬
Affiliation: H3D, inc, Massachusetts General Hospital, M3D, Inc 🌍
Purpose: To evaluate the potential of using real-time imaging and dose measurement to find weak spots and leaks in bedside shielding systems during diagnostic or interventional fluoroscopic procedures.
Methods: We used a hand-held radiation camera with real-time radiation imaging and dose rate measurement capabilities to image several shielding barriers including portable leaded plexiglass and a bed-mounted movable fluoroscopic shielding system. First two portable leaded plexiglass barriers (1 cm and 3.5 cm lead equivalent thickness) were set up with an intentional 2 cm gap between them and a portable 50 kVp (8mas) x-ray generator placed 2 meters behind them with the hand-held radiation camera place 2 meters in front of them. Images of the x-ray scatter and penetration through the barriers and the gap between barriers were acquired. Next, intentional gaps were left in a mobile bed mounted fluoroscopic shielding system and images were acquired during delivery of clinical fluoroscopic x-ray beam. Dose rate measurements acquired with the hand-held imager were compared to measurements acquired with a calibrated survey meter.
Results: These studies showed that real-time imaging (video) of the x-ray scatter and penetration through the barriers could be acquired during the delivery of the fluoroscopy beams. Not only were gaps in the shielding visible, but weak/thin spots in the shielding with increased x-ray penetration could also be identified. As the shielding was adjusted to remove the gaps, the intensity of the x-ray scatter images decreased/disappeared. Dose rate measurements made with the hand-held imager agreed with calibrated survey meter within ±20%.
Conclusion: The hand-held imager was shown to provide valuable real-time information on the location of gaps and weak spots in the fluoroscopic shielding. This allowed for real-time adjustment of the shielding or the positioning of hospital staff during a procedure to help reduce/eliminate unwanted exposures to during fluoroscopic procedures.