A Monte Carlo Study Of The X-ray Scattering In Interventional Operation

Because of small trauma,quick curative effect and high accuracy,image-guided interventional surgery has been applied widely in clinical practice.Image guidance uses X-rays generally.During the operation,the operator stands so close to the patient that expose themselves in the radiation field.The patient is physically regarded as a secondary radiation source that emits scattered X-rays.Nowadays the thermoluminescence dosimeter used to measure the radiation dose is different with the real dose.The dose value should be modified by energy.Therefore,studying the effects of the scatterer material and thickness,irradiation field and spatial position has guiding significance on protection of surgeon.In this paper,the author uses the Monte Carlo(MC)method to simulate the X-ray energy in the following four conditions:1)X-rays transmit 1 cm ~ 45 cm water model 2)in different horizontal positions;3)X-rays emission in the angle of 30°~50°;4)different scatterer.Then getting the scattering X-rays energy spectrum and analyzing of the law and verifying the reliability of the simulation conclusion through experiments.The simulation results show that: 1)with the increasing of the thickness,the scattering X-rays energy decreases,and the number of scattered photons increase at the beginning and then decrease;2)with the increase of horizontal distance,the scattering X-rays energy reduces;3)the scattering X-rays energy increases with the increase of the launch angle;4)with the increase of the iron ball's radius in the water model,the scattering X-rays energy does not change and the number of scattered photons decreases.5)X-rays with characteristic lines,the characteristic lines disappear with the increase of the thickness of the scatterer;6)X-rays energy in shadow companion area is less than that in field area.The research in this paper has practical significance in the measurement and protection of scattered rays in image-guided interventional therapy.