title: Radiation exposure during continuous and pulsed fluoroscopy.
abstract: Abstract Background and Purpose: Previous studies using pulsed fluoroscopy have shown variable effects on radiation exposure because of the ramp and trail effect in older C-arm systems. This study compares radiation delivered in pulsed and continuous modalities using a modern C-arm system.
  
  
  METHODS
  Thermoluminescent dosimeters (TLDs) positioned in three body locations directly measured radiation dose during simulated ureteroscopy. Thirty pedal activations were administered using a pulsed or continuous mode to visualize an implanted guidewire and a radiopaque stone. TLD absorbed radiation and image quality were compared between imaging modes.
  
  
  RESULTS
  Pulsed fluoroscopy delivered less radiation compared with continuous fluoroscopy at each site: Anterior skin (0.10 vs 0.26 mGy, P<0.001), kidney (0.15 vs 0.40 mGy, P<0.001), and posterior skin (0.92 vs 2.62 mGy, P<0.001). Mean fluoroscopy time differed between continuous and pulsed modes (12.5 vs 3.0 seconds; P<0.001). Fluoroscopy time positively correlated with radiation exposure at all sites: Anterior skin (0.017 mGy/s, R(2)=0.90), left kidney (0.026 mGy/s, R(2)=0.96), and posterior skin (0.18 mGy/sec, R(2)=0.98). When evaluated by blinded urologists, 100% of reviewers felt pulsed images were adequate to identify guidewire position and 90.5% felt pulsed images were adequate for stone localization.
  
  
  CONCLUSIONS
  Pulsed fluoroscopy reduced fluoroscopy time by 76% and radiation dose by 64% compared with continuous fluoroscopy. Pulsed fluoroscopy images were adequate for most tasks of ureteroscopy and should be considered for reduction of radiation during ureteroscopy.
authors.affiliation: Department of Urology, Loma Linda Universit , Loma Linda, CA 92354, USA.
authors.forename: Damien L
authors.initials: DL
authors.lastname: Smith
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Heldt
authors.forename: Gideon D
authors.initials: GD
authors.lastname: Richards
authors.forename: Gautum
authors.initials: G
authors.lastname: Agarwal
authors.forename: Wayne G
authors.initials: WG
authors.lastname: Brisbane
authors.forename: Catherine J
authors.initials: CJ
authors.lastname: Chen
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Chamberlin
authors.forename: D Duane
authors.initials: DD
authors.lastname: Baldwin
mesh_terms: D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted