Patency of coronary bypass grafts: assessment with breath-hold contrast-enhanced MR angiography--value of a non-electrocardiographically triggered technique.
OBJECTIVE
To determine the value of non-electrocardiographically triggered contrast material-enhanced magnetic resonance (MR) angiography in assessing the patency of venous and internal thoracic artery (ITA) grafts after coronary bypass surgery.


METHODS
Twenty-seven patients with 76 coronary bypass grafts (48 venous, 28 ITA) were examined 26.5 months +/- 5.8 after surgery with MR angiography and conventional angiography. MR angiography was performed with a three-dimensional gradient-echo sequence after automated injection of contrast material; contrast agent administration was based on measurement of the individual transit time of the agent. Results of MR angiography were interpreted by two independent observers and compared with results of conventional angiography.


RESULTS
The independent interpretations of the MR angiograms agreed with the results of conventional angiography in 96% and 91% of the grafts. After a final consensus reading, sensitivity was 95% for all grafts, 94% for venous grafts, and 96% for ITA grafts. Specificity was 85% for venous grafts and 67% for ITA grafts. Positive predictive value was 95% for all grafts, 94% for venous grafts, and 96% for ITA grafts.


CONCLUSIONS
Non-electrocardiographically triggered contrast-enhanced MR angiography allows reliable assessment of the patency of venous and arterial coronary bypass grafts.
Department of Diagnostic Radiology, Klinikum Grosshadern, Ludwig-Maximilians-University Munich, Germany.
B J
BJ
Wintersperger
M G
MG
Engelmann
A
A
von Smekal
A
A
Knez
H V
HV
Penzkofer
B
B
Höfling
G
G
Laub
M F
MF
Reiser
D000328:Adult; D000368:Aged; D001158:Arteries / Q000637:transplantation; D003287:Contrast Media; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000175:diagnosis* / Q000601:surgery; D003331:Coronary Vessels / Q000473:pathology; D005260:Female; D019786:Gadolinium DTPA; D006083:Graft Occlusion, Vascular / Q000175:diagnosis*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012123:Pulmonary Ventilation / Q000502:physiology; D012680:Sensitivity and Specificity; D014680:Veins / Q000637:transplantation
D003287:Contrast Media; D019786:Gadolinium DTPA