PATENCY OF CORONARY-BYPASS GRAFTS - ASSESSMENT WITH BREATH-HOLD CONTRAST-ENHANCED MR-ANGIOGRAPHY - VALUE OF A NON-ELECTROCARDIOGRAPHICALLY TRIGGERED TECHNIQUE

PURPOSE: To determine the value of non-electrocardiographically trigge red contrast material-enhanced magnetic resonance (MR) angiography in assessing the patency of venous and internal thoracic artery (ITA) gra fts after coronary bypass surgery. MATERIALS AND METHODS: Twenty-seven patients with 76 coronary bypass grafts (48 venous, 28 ITA) were exam ined 26.5 months +/- 5.8 after surgery with MR angiography and convent ional angiography. MR angiography was performed with a three-dimension al gradient-echo sequence after automated injection of contrast materi al; contrast agent administration was based on measurement of the indi vidual transit time of the agent. Results of MR angiography were inter preted by two independent observers and compared with results of conve ntional angiography. RESULTS: The independent interpretations of the M R angiograms agreed with the results of conventional angiography in 96 % for all grafts, 91% for venous grafts, and 96% for ITA grafts. Speci ficity was 85% for venous grafts and 67% for ITA grafts. Positive pred ictive value was 95% for all grafts, 94% for venous grafts, and 96% fo r ITA grafts. CONCLUSION: Non-electrocardiographically triggered contr ast-enhanced MR angiography allows reliable assessment of the patency of venous and arterial coronary bypass grafts.