title: Radiation exposure with the NOMAD portable X-ray system.
abstract: OBJECTIVE
  A new hand-held battery-operated portable X-ray system was tested for possible leakage radiation through the existing heavy metal compounds surrounding the X-ray tube, backscatter radiation through the lead-filled acrylic shield attached at the end of the exit tube and patient exposure.
  
  
  METHODS
  Dose measurements were conducted using a DXTRR phantom and a water phantom. All measurements were recorded using calibrated thermoluminescent dosimetry (TLD), calibrated Unfors Model 583L dosemeter, and a calibrated Radcal MDH model 1015 dosemeter. The settings for all exposure were 60 kVp, 2.3 mA and 0.25 s using Kodak Insight (Class F) film.
  
  
  RESULTS
  All backscatter measurements, in front of the shield, behind the shield, at the finger of the operator, the operator's chest, eyes and gonads were significantly below the maximum permissible radiation leakage as per the United States Food and Drug Administration regulations (100 mR h(-1)). Our measurements indicate that the exposure would be well within the occupational maximum permissible dose for an occupationally exposed person. Film dose was consistent with the manufacturer's recommendations. As a result of our measurements, the State of New York Bureau of Environmental Radiation Protection granted us a variance to use the NOMAD on a case-by-case basis.
  
  
  CONCLUSIONS
  Our data have shown that the NOMAD presents risks that are no greater than with standard dental radiographic units to the patient or operator and the measured doses are well below recommended levels.
authors.affiliation: Department of General Dentistry, School of Dental Medicine, SUNY Stony Brook, New York, NY 11794, USA. agoren@notes.cc.sunysb.edu
authors.forename: A D
authors.initials: AD
authors.lastname: Goren
authors.forename: M
authors.initials: M
authors.lastname: Bonvento
authors.forename: J
authors.initials: J
authors.lastname: Biernacki
authors.forename: D C
authors.initials: DC
authors.lastname: Colosi
mesh_terms: D018795:Device Approval; D006801:Humans; D009518:New York; D016273:Occupational Exposure; D019047:Phantoms, Imaging; D011835:Radiation Protection / Q000379:methods*; D011861:Radiography, Dental / Q000295:instrumentation*; D012542:Scattering, Radiation; D013819:Thermoluminescent Dosimetry; D014481:United States; D014486:United States Food and Drug Administration