Evaluating lead thickness for Shielding during Computed tomography using Monte Carlo Simulation

The objective of this study was to determine the appropriate thickness of lead shielding for computerized tomography (CT) and mock estimate the transmission spectrum according to changes in lead thickness based on computational simulation of CT apparatus. Based on the technical manual of the CT equipment company, CT device configuration was simulated with Monte Carlo simulation code. As shielding material for CT, lead, the most used one, was selected. Lead thickness was simulated by setting it from 0 (absence of shielding material) to 1.25 mm. With increasing lead thickness, the probability of photon absorption was increased while transmittance was estimated to be reduced. In addition, photon permeability was estimated to be 50% or less with lead thickness of 0.05 mm. However, photon absorption probability was estimated to be 90% or more with lead thickness of 0.375 mm with 10%. In computational simulation transmittance experiment of computed tomography using Monte Carlo simulated code, the appropriate lead thickness of the shield was found to be 0.5 mm.