title: Predictive respiratory gating: a new method to reduce motion artifacts on CT scans.
abstract: OBJECTIVE
  To evaluate a gating system, called predictive respiratory gating (PRG), that reduces motion-induced artifacts on computed tomographic (CT) scans of patients who cannot suspend respiration.
  
  
  METHODS
  PRG uses a respiration monitor and a new algorithm to predict when a motionless period is about to occur. It automatically starts scanning so the scan is temporally centered around the motionless period at end inspiration or end expiration. To demonstrate PRG, CT was performed on a motion phantom and a quietly breathing volunteer with and without gating.
  
  
  RESULTS
  Scans of the phantom obtained with PRG contained less motion-induced streaking and blurring than did scans acquired without PRG. Scans of the volunteer gated at end expiration contained significantly less artifact than nongated scans (P < .03).
  
  
  CONCLUSIONS
  PRG reduced motion artifact on scans of a spontaneously breathing volunteer. PRG may be able to reduce motion artifacts on scans of patients unable to suspend respiration.
authors.affiliation: Department of Bioengineering, University of Washington, Seattle 98195.
authors.forename: C J
authors.initials: CJ
authors.lastname: Ritchie
authors.forename: J
authors.initials: J
authors.lastname: Hsieh
authors.forename: M F
authors.initials: MF
authors.lastname: Gard
authors.forename: J D
authors.initials: JD
authors.lastname: Godwin
authors.forename: Y
authors.initials: Y
authors.lastname: Kim
authors.forename: C R
authors.initials: CR
authors.lastname: Crawford
mesh_terms: D000328:Adult; D000465:Algorithms; D016477:Artifacts; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D008961:Models, Structural; D008991:Monitoring, Physiologic / Q000295:instrumentation; D009068:Movement; D012119:Respiration / Q000502:physiology*; D014057:Tomography, X-Ray Computed / Q000379:methods*