title: Pulmonary vein imaging with unenhanced three-dimensional balanced steady-state free precession MR angiography: initial clinical evaluation.
abstract: OBJECTIVE
  To determine whether unenhanced magnetic resonance (MR) angiography performed with a three-dimensional (3D) segmented steady-state free precession (SSFP) sequence would be an alternative to contrast material-enhanced MR angiography for evaluating pulmonary veins (PVs) prior to and following radiofrequency (RF) ablation for atrial fibrillation.
  
  
  METHODS
  MR angiographic examinations of PVs, performed in 20 patients (nine men, 11 women; mean age, 56.4 years +/- 12.7 [standard deviation]), were retrospectively reviewed according to an institutional review board-approved protocol. The number of PVs and their orthogonal measurements obtained from the 3D SSFP images were compared with those obtained from contrast-enhanced MR angiography. Signal-to-noise and contrast-to-noise ratios were also compared. Qualitative assessment of both techniques was performed by independent reviewers who scored the image quality (on a scale of 1 to 5) on the basis of PV conspicuity. The presence of cardiac and extracardiac pathologic indicators was also determined. Bland-Altman and Wilcoxon signed rank statistical analyses were performed.
  
  
  RESULTS
  The mean difference in PV diameter measurements between contrast-enhanced MR angiography and 3D SSFP was -0.02 cm +/- 0.25. Signal-to-noise and contrast-to-noise ratios were higher for 3D SSFP images than for contrast-enhanced MR angiograms. Qualitatively, there was no significant difference in PV conspicuity between the techniques. Noncardiac pathologic indicators were detected in 10 of 20 patients on 3D SSFP images but not on contrast-enhanced MR angiograms.
  
  
  CONCLUSIONS
  Unenhanced PV MR angiography performed by using a free-breathing 3D SSFP technique is as accurate as contrast-enhanced MR angiography for measuring PV diameter. This technique can be used for patients in whom contrast-enhanced computed tomographic or MR angiography is contraindicated and may be sufficient in all patients.
authors.affiliation: Department of Radiology, Northwestern University, Chicago, Ill, USA. cfrancois@uwhealth.org
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: François
authors.forename: David
authors.initials: D
authors.lastname: Tuite
authors.forename: Vibhas
authors.initials: V
authors.lastname: Deshpande
authors.forename: Renate
authors.initials: R
authors.lastname: Jerecic
authors.forename: Peter
authors.initials: P
authors.lastname: Weale
authors.forename: James C
authors.initials: JC
authors.lastname: Carr
mesh_terms: D000465:Algorithms; D005240:Feasibility Studies; D005260:Female; D006329:Heart Conduction System / Q000473:pathology*; 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; D010865:Pilot Projects; D011667:Pulmonary Veins / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity