title: Occupational and patient exposure as well as image quality for full spine examinations with the EOS imaging system.
abstract: OBJECTIVE
  EOS (EOS imaging S.A, Paris, France) is an x-ray imaging system that uses slot-scanning technology in order to optimize the trade-off between image quality and dose. The goal of this study was to characterize the EOS system in terms of occupational exposure, organ doses to patients as well as image quality for full spine examinations.
  
  
  METHODS
  Occupational exposure was determined by measuring the ambient dose equivalents in the radiological room during a standard full spine examination. The patient dosimetry was performed using anthropomorphic phantoms representing an adolescent and a five-year-old child. The organ doses were measured with thermoluminescent detectors and then used to calculate effective doses. Patient exposure with EOS was then compared to dose levels reported for conventional radiological systems. Image quality was assessed in terms of spatial resolution and different noise contributions to evaluate the detector's performances of the system. The spatial-frequency signal transfer efficiency of the imaging system was quantified by the detective quantum efficiency (DQE).
  
  
  RESULTS
  The use of a protective apron when the medical staff or parents have to stand near to the cubicle in the radiological room is recommended. The estimated effective dose to patients undergoing a full spine examination with the EOS system was 290 μSv for an adult and 200 μSv for a child. MTF and NPS are nonisotropic, with higher values in the scanning direction; they are in addition energy-dependent, but scanning speed independent. The system was shown to be quantum-limited, with a maximum DQE of 13%. The relevance of the DQE for slot-scanning system has been addressed.
  
  
  CONCLUSIONS
  As a summary, the estimated effective dose was 290 μSv for an adult; the image quality remains comparable to conventional systems.
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1007, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Damet
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1007, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Fournier
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1007, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Monnin
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1007, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Sans-Merce
authors.affiliation: Department of Paediatrics, Division of paediatric orthopaedic, University Hospitals of Geneva, Geneva 1205, Switzerland.
authors.forename: D
authors.initials: D
authors.lastname: Ceroni
authors.affiliation: Department of Radiology, Division of paediatric radiology, University Hospitals of Geneva, Geneva 1205, Switzerland.
authors.forename: T
authors.initials: T
authors.lastname: Zand
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1007, Switzerland.
authors.forename: F R
authors.initials: FR
authors.lastname: Verdun
authors.affiliation: Institute of Radiation Physics, Lausanne University Hospital, Lausanne 1007, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Baechler
mesh_terms: D000293:Adolescent; D000328:Adult; D016477:Artifacts; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008954:Models, Biological; D016273:Occupational Exposure / Q000517:prevention & control; D019047:Phantoms, Imaging; D011481:Protective Clothing; D011829:Radiation Dosage; D011859:Radiography / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D011871:Radiology; D013131:Spine / Q000000981:diagnostic imaging*; D013819:Thermoluminescent Dosimetry