title: Direct monitoring of coronary artery motion with cardiac fat navigator echoes.
abstract: Navigator echoes (NAVs) provide an effective means of monitoring physiological motion in magnetic resonance imaging (MRI). Motion artifacts can be suppressed by adjusting the data acquisition accordingly. The standard pencil-beam NAV has been used to detect diaphragm motion; however, it does not monitor cardiac motion effectively. Here we report a navigator approach that directly measures coronary artery motion by exciting the surrounding epicardial fat and sampling the signal with a k-space trajectory sensitized to various motion parameters. The present preliminary human study demonstrates that superior-inferior (SI) respiratory motion of the coronary arteries detected by the cardiac fat NAV highly correlates with SI diaphragmatic motion detected by the pencil-beam NAV. In addition, the cardiac fat navigator gating is slightly more effective than the diaphragmatic navigator gating in suppressing motion artifacts in free-breathing 3D coronary MR angiography (MRA).
authors.affiliation: MR Research Center, Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Thanh D
authors.initials: TD
authors.lastname: Nguyen
authors.forename: Anthony
authors.initials: A
authors.lastname: Nuval
authors.forename: Suresh
authors.initials: S
authors.lastname: Mulukutla
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology; D000328:Adult; D016477:Artifacts; D003331:Coronary Vessels / Q000033:anatomy & histology*; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D009038:Motion; D010496:Pericardium / Q000033:anatomy & histology