title: Monte Carlo simulation of the dose distribution of ICRP adult reference computational phantoms for acquisitions with a 320 detector-row cone-beam CT scanner.
abstract: OBJECTIVE
  The purpose of this study was to develop and validate a Monte Carlo (MC) simulation tool for patient dose assessment for a 320 detector-row CT scanner, based on the recommendations of International Commission on Radiological Protection (ICRP). Additionally, the simulation was applied on four clinical acquisition protocols, with and without automatic tube current modulation (TCM).
  
  
  METHODS
  The MC simulation was based on EGS4 code and was developed specifically for a 320 detector-row cone-beam CT scanner. The ICRP adult reference phantoms were used as patient models. Dose measurements were performed free-in-air and also in four CTDI phantoms: 150 mm and 350 mm long CT head and CT body phantoms. The MC program was validated by comparing simulations results with these actual measurements acquired under the same conditions. The measurements agreed with the simulations across all conditions within 5%. Patient dose assessment was performed for four clinical axial acquisitions using the ICRP adult reference phantoms, one of them using TCM.
  
  
  RESULTS
  The results were nearly always lower than those obtained from other dose calculator tools or published in other studies, which were obtained using mathematical phantoms in different CT systems. For the protocol with TCM organ doses were reduced by between 28 and 36%, compared to the results obtained using a fixed mA value.
  
  
  CONCLUSIONS
  The developed simulation program provides a useful tool for assessing doses in a 320 detector-row cone-beam CT scanner using ICRP adult reference computational phantoms and is ready to be applied to more complex protocols.
authors.affiliation: Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili, C/Sant Llorenç, 21, 43201 Reus, Spain. Electronic address: m.salvado@urv.cat.
authors.forename: M
authors.initials: M
authors.lastname: Salvadó
authors.affiliation: Faculty of Medicine and Health Sciences, Universitat Rovira i Virgili, C/Sant Llorenç, 21, 43201 Reus, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Cros
authors.affiliation: Radiology Department, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
authors.forename: R M S
authors.initials: RM
authors.lastname: Joemai
authors.affiliation: Radiology Department, Universidad Complutense de Madrid, Avenida Complutense, 28040 Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Calzado
authors.affiliation: Radiology Department, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Geleijns
mesh_terms: D000328:Adult; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection; D012984:Software
keywords: 320 Detector-row cone beam CT scanner; Computed Tomography dose assessment; ICRP adult reference computational phantoms; Monte Carlo simulation