title: Coronary artery imaging with real-time navigator three-dimensional turbo-field-echo MR coronary angiography: initial experience.
abstract: OBJECTIVE
  To examine the value of a commercially available three-dimensional (3D) real-time navigator magnetic resonance (MR) coronary angiographic examination for detection of significant coronary artery stenoses, with conventional coronary angiography as the standard of reference.
  
  
  METHODS
  Twenty-one patients underwent 3D navigator MR coronary angiography immediately before catheterization. Two observers independently graded image quality on a scale from 1 (unreadable) to 5 (excellent), quantified coronary artery visualization, and evaluated the presence of significant (ie, >50% narrowing) stenoses. kappa statistics were used to assess interobserver agreement, and receiver operating characteristic (ROC) analysis was used to assess stenosis detection.
  
  
  RESULTS
  For two of 21 patients, MR coronary angiogram quality was insufficient for analysis (mean score < 2). For the remaining 19 patients, the mean image quality scores assigned by observers 1 and 2 were 3.3 +/- 1.0 (SD) and 3.2 +/- 0.9, respectively. A mean of 71% of all coronary artery segments were visible at MR coronary angiography, and there was 91% agreement between the observers (kappa = 0.78). Observers 1 and 2 detected significant stenoses (n = 29) at MR coronary angiography with sensitivities of 44.4% and 55.5%, respectively; specificities of 95.1% and 83.7%, respectively; and 80% agreement (kappa = 0.35). Areas under the ROC curve were 0.817 and 0.795 for observers 1 and 2, respectively.
  
  
  CONCLUSIONS
  Large portions of the coronary arteries can be visualized with MR coronary angiography. Imaging results are not consistently reliable, however. The examination is premature for routine clinical assessment of significant coronary artery stenosis owing to low sensitivity and large observer variability.
authors.affiliation: Department of Radiology, Gasthuisberg University Hospital, Leuven, Belgium. jan.bogaert@uz.kuleuven.ac.be
authors.forename: Jan
authors.initials: J
authors.lastname: Bogaert
authors.forename: Ronald
authors.initials: R
authors.lastname: Kuzo
authors.forename: Steven
authors.initials: S
authors.lastname: Dymarkowski
authors.forename: Roel
authors.initials: R
authors.lastname: Beckers
authors.forename: Jan
authors.initials: J
authors.lastname: Piessens
authors.forename: Frank E
authors.initials: FE
authors.lastname: Rademakers
mesh_terms: D000328:Adult; D000368:Aged; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000175:diagnosis*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D012372:ROC Curve; D012680:Sensitivity and Specificity