Efficacy of lower-body shielding in computed tomography fluoroscopy-guided interventions.
OBJECTIVE
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.


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.


CONCLUSIONS
Lower-body shielding is an effective way to decrease radiation exposure to the interventionalist and should routinely be used in CT fluoroscopy-guided interventions.
Department of Diagnostic and Interventional Radiology, RWTH Aachen, 52074, Aachen, Germany. mahnken@rad.rwth-aachen.de
Andreas H
AH
Mahnken
Martin
M
Sedlmair
Christine
C
Ritter
Rosemarie
R
Banckwitz
Thomas
T
Flohr
D005471:Fluoroscopy; D006801:Humans; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D012542:Scattering, Radiation; D014057:Tomography, X-Ray Computed