title: High-resolution 3D coronary vessel wall imaging with near 100% respiratory efficiency using epicardial fat tracking: reproducibility and comparison with standard methods.
abstract: OBJECTIVE
  To quantitatively assess the performance and reproducibility of 3D spiral coronary artery wall imaging with beat-to-beat respiratory-motion-correction (B2B-RMC) compared to navigator gated 2D spiral and turbo-spin-echo (TSE) acquisitions.
  
  
  METHODS
  High-resolution (0.7 × 0.7 mm) cross-sectional right coronary wall acquisitions were performed in 10 subjects using four techniques (B2B-RMC 3D spiral with alternate (2RR) and single (1RR) R-wave gating, navigator-gated 2D spiral (2RR) and navigator-gated 2D TSE (2RR)) on two occasions. Wall thickness measurements were compared with repeated measures analysis of variance (ANOVA). Reproducibility was assessed with the intraclass correlation coefficient (ICC).
  
  
  RESULTS
  In all, 91% (73/80) of acquisitions were successful (failures: four TSE, two 3D spiral (1RR) and one 3D spiral (2RR)). Respiratory efficiency of the B2B-RMC was less variable and substantially higher than for navigator gating (99.6 ± 1.2% vs. 39.0 ± 7.5%, P < 0.0001). Coronary wall thicknesses (± standard deviation [SD]) were not significantly different: 1.10 ± 0.14 mm (3D spiral (2RR)), 1.20 ± 0.16 mm (3D spiral (1RR)), 1.14 ± 0.15 mm (2D spiral), and 1.21 ± 0.17 mm (TSE). Wall thickness reproducibility ranged from good (ICC = 0.65, 3D spiral (1RR)) to excellent (ICC = 0.87, 3D spiral (2RR)).
  
  
  CONCLUSIONS
  High-resolution 3D spiral imaging with B2B-RMC permits coronary vessel wall assessment over multiple thin contiguous slices in a clinically feasible duration. Excellent reproducibility of the technique potentially enables studies of disease progression/regression.
authors.affiliation: Cardiovascular Magnetic Resonance Unit, National Heart and Lung Institute, Imperial College London, London, UK. a.scott07@imperial.ac.uk
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Scott
authors.forename: Jennifer
authors.initials: J
authors.lastname: Keegan
authors.forename: David N
authors.initials: DN
authors.lastname: Firmin
mesh_terms: D000273:Adipose Tissue / Q000033:anatomy & histology*; D000328:Adult; D000465:Algorithms; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D003331:Coronary Vessels / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated / Q000379:methods; D010496:Pericardium / Q000033:anatomy & histology*; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D013382:Subtraction Technique