title: Coronary artery bypass graft patency: assessment with true ast imaging with steady-state precession versus gadolinium-enhanced MR angiography.
abstract: OBJECTIVE
  To compare the accuracy of multisection true fast imaging with steady-state precession (FISP) with gadolinium-enhanced magnetic resonance (MR) angiography for the detection of coronary artery bypass graft patency.
  
  
  METHODS
  Twenty-five patients with coronary artery bypass grafts who had recently undergone conventional coronary angiography underwent MR angiography with a 1.5-T system. True FISP angiographic images were acquired in transverse and coronal planes. Coronal cardiac-gated MR angiography was performed with 0.2 mL per kilogram of body weight of gadopentetate dimeglumine injected at a rate of 2 mL/sec. With conventional angiography as the reference standard, the sensitivity, specificity, and accuracy of each technique for the detection of graft patency were determined. Image quality and duration of analysis were determined by two experienced radiologists.
  
  
  RESULTS
  In 25 patients, 46 of 56 venous grafts were patent and 22 of 23 arterial grafts were patent. In all grafts at true FISP angiography, sensitivity for patency was 84% (57 of 68 grafts), specificity was 45% (five of 11 grafts), and accuracy was 78% (62 of 79 grafts). At MR angiography, sensitivity was 85% (58 of 68 grafts), specificity was 73% (eight of 11 grafts), and accuracy was 84% (66 of 79 grafts) (difference not significant). Image quality scores were similar with both techniques, but duration of analysis was significantly longer with MR angiography than with true FISP angiography (29 minutes 24 seconds vs 14 minutes 6 seconds, P <.001).
  
  
  CONCLUSIONS
  Accuracy for detection of coronary artery bypass graft patency was similar with gadolinium-enhanced MR angiography and true FISP angiography, with a trend toward more false-positive findings for occlusion and reduced visualization of arterial grafts with true FISP angiography.
authors.affiliation: Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Sydney St, London SW3 6NP, England.
authors.forename: Nicholas H
authors.initials: NH
authors.lastname: Bunce
authors.forename: Christine H
authors.initials: CH
authors.lastname: Lorenz
authors.forename: Anna S
authors.initials: AS
authors.lastname: John
authors.forename: John R
authors.initials: JR
authors.lastname: Lesser
authors.forename: Raad H
authors.initials: RH
authors.lastname: Mohiaddin
authors.forename: Dudley J
authors.initials: DJ
authors.lastname: Pennell
mesh_terms: D003287:Contrast Media; D001026:Coronary Artery Bypass; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014654:Vascular Patency
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA