title: Prospective navigator correction of image position for coronary MR angiography.
abstract: OBJECTIVE
  To determine the potential benefit of prospective navigator correction of image position for coronary magnetic resonance (MR) angiography.
  
  
  METHODS
  Two-dimensional MR angiograms were obtained with free breathing in 12 adult subjects. Navigator gating was used with and without prospective correction and with gating windows set at 3, 5, and 7 mm. MR angiograms were compared with those obtained with conventional, end-expiratory breath holding.
  
  
  RESULTS
  Navigator gating with correction resulted in image quality equivalent to that obtained with breath holding, even with the 7-mm gating window. In contrast, navigator gating without correction allowed only maintenance of image quality similar to that obtained with breath holding for the 3- and 5-mm windows and resulted in decreased image quality with the 7-mm window (P < .05). Use of navigator gating with correction and the 7-mm window resulted in a 28% decrease in imaging time compared with breath holding and a 33% decrease compared with the 3-mm gating window (P < .05 for both comparisons).
  
  
  CONCLUSIONS
  Prospective, adaptive navigator correction of image position for free-breathing coronary MR angiography is a promising, novel approach to compensate for respiratory motion.
authors.affiliation: Charles A. Dana Research Institute, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA 02215, USA.
authors.forename: P G
authors.initials: PG
authors.lastname: Danias
authors.forename: M V
authors.initials: MV
authors.lastname: McConnell
authors.forename: V C
authors.initials: VC
authors.lastname: Khasgiwala
authors.forename: M L
authors.initials: ML
authors.lastname: Chuang
authors.forename: R R
authors.initials: RR
authors.lastname: Edelman
authors.forename: W J
authors.initials: WJ
authors.lastname: Manning
mesh_terms: D000328:Adult; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D009068:Movement; D011446:Prospective Studies; D012119:Respiration; D013997:Time Factors