title: Dose reduction fluoroscopy in pediatrics.
abstract: BACKGROUND
  It is essential that we find ways to reduce radiation exposure to children and maintain image quality.
  
  
  OBJECTIVE
  We compared radiation dose, image quality, and spatial resolution when continuous and pulse fluoroscopy with a full and half dose are applied to a phantom. The film-screen technique was compared to fluoroscopy with the digitized spot technique (fluoro grab image) in procedures such as voiding cystourethrogram (VCUG).
  
  
  METHODS
  Using a 15.1-cm Plexiglas phantom, we obtained dosimetry in milligrays (mGy), spatial resolution in number of line pairs per millimeter (lp/mm), and threshold contrast resolution in number of visible holes. To measure total radiation dose, we calculated the average elapsed fluoroscopy time for VCUG to be approximately 3 min and estimated the average number of exposures as 10. Dosimetry was obtained for full dose and half dose continuous, for 15 pulses per second (pps), 7.5 pps, and 3.75 pps. These were also calculated with normal, magnification 1, and magnification 2 factors.
  
  
  RESULTS
  Results of the two most relevant parameters are shown: continuous full-dose fluoroscopy, 3 min, 10 photo spots, total dose of 28.7 mGy with 2 lp/mm of resolution and a threshold contrast of 2.2%, versus 3.75 pps half-dose fluoroscopy, 3 min, grab images, total dose of 3.7 mGy with 1.9 lp/mm of resolution and a threshold contrast of 2.3%.
  
  
  CONCLUSIONS
  With minimal loss of resolution there is significant dose reduction (87%) when using 3.75 pps with digitized imaging.
authors.affiliation: Department of Radiology, University of Pennsylvania Medical School, Philadelphia, Pennsylvania, USA.
authors.forename: Henrique M
authors.initials: HM
authors.lastname: Lederman
authors.forename: Zarir P
authors.initials: ZP
authors.lastname: Khademian
authors.forename: Marc
authors.initials: M
authors.lastname: Felice
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Hurh
mesh_terms: D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D010372:Pediatrics; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods; D012867:Skin / Q000528:radiation effects