title: Clinical apparatus for the reduction of dose area product for patients undergoing x-ray catheterization.
abstract: OBJECTIVE
  The authors describe a design for prepatient region of interest attenuators (ROIAs) to reduce dose area product (DAP) for clinical use. The authors describe a model to predict DAP values from x-ray technique parameters recorded during a clinical procedure for image sequences obtained in the presence or absence of ROIAs. The model was developed primarily to determine what the DAP to a patient undergoing cardiac catheterization with a ROIA would have been if no ROIA had been used allowing a determination of DAP reduction.
  
  
  METHODS
  Copper ROIAs with thicknesses that vary gradually so as not to cause significant image artifacts were constructed. X-ray image sequences were acquired on a clinical catheterization system with and without ROIAs with varying x-ray technique parameters. DAP values were measured for all said exposures using an ionization chamber and compared to a model the authors developed.
  
  
  RESULTS
  The model can predict DAP values within 3.5% on average with or without ROIAs when compared to ionization chamber measurements.
  
  
  CONCLUSIONS
  The proposed experimental design is adequate for measuring DAP reductions on the order of 1.5-3.5 that are expected when introducing a ROIA during patient catheterization imaging.
authors.affiliation: Sunnybrook Research Institute, 2075 Bayview Avenue, Room S633, Toronto, Ontario M4N 3M5, Canada.
authors.forename: Normand
authors.initials: N
authors.lastname: Robert
authors.affiliation: Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada.
authors.forename: Kristina N
authors.initials: KN
authors.lastname: Watt
authors.affiliation: Sunnybrook Research Institute, Toronto, Ontario M4N 3M5, Canada.
authors.forename: Sophie
authors.initials: S
authors.lastname: Rochette
authors.affiliation: General Electric, 283 rue de la Miniére, Buc 78533, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Desponds
authors.affiliation: General Electric, 283 rue de la Miniére, Buc 78533, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Vaillant
authors.affiliation: Sunnybrook Research Institute, 2075 Bayview Avenue, Room S633, Toronto, Ontario M4N 3M5, Canada.
authors.forename: John A
authors.initials: JA
authors.lastname: Rowlands
mesh_terms: D016477:Artifacts; D006328:Cardiac Catheterization / Q000379:methods*; D005471:Fluoroscopy / Q000379:methods; D006801:Humans; D008962:Models, Theoretical; D011829:Radiation Dosage; D015641:Radiography, Interventional / Q000295:instrumentation* / Q000379:methods*; D014965:X-Rays