Published in:
01-12-2012 | Laboratory Investigation
Efficacy of Lower-Body Shielding in Computed Tomography Fluoroscopy-Guided Interventions
Authors:
Andreas H. Mahnken, Martin Sedlmair, Christine Ritter, Rosemarie Banckwitz, Thomas Flohr
Published in:
CardioVascular and Interventional Radiology
|
Issue 6/2012
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Abstract
Purpose
Computed tomography (CT) fluoroscopy-guided interventions pose relevant radiation exposure to the interventionalist. The goal of this study was to analyze the efficacy of lower-body shielding as a simple structural method for decreasing radiation dose to the interventionalist without limiting access to the patient.
Material and Methods
All examinations were performed with a 128-slice dual source CT scanner (12 × 1.2-mm collimation; 120 kV; and 20, 40, 60, and 80 mAs) and an Alderson-Rando phantom. Scatter radiation was measured with an ionization chamber and a digital dosimeter at standardized positions and heights with and without a lower-body lead shield (0.5-mm lead equivalent; Kenex, Harlow, UK). Dose decreases were computed for the different points of measurement.
Results
On average, lower-body shielding decreased scatter radiation by 38.2% within a 150-cm radius around the shielding. This decrease is most significant close to the gantry opening and at low heights of 50 and 100 cm above the floor with a maximum decrease of scatter radiation of 95.9% close to the scanner’s isocentre. With increasing distance to the gantry opening, the effect decreased. There is almost no dose decrease effect at ≥150 above the floor. Scatter radiation and its decrease were linearly correlated with the tube current-time product (r
2 = 0.99), whereas percent scatter radiation decrease was independent of the tube current-time product.
Conclusion
Lower-body shielding is an effective way to decrease radiation exposure to the interventionalist and should routinely be used in CT fluoroscopy-guided interventions.