Hybrid PET/MRI allows the acquisition of both fluorine-18-fluorodeoxyglucose (18F-FDG) PET and cardiac magnetic resonance (CMR) during one session. Whether this will result in different referral to coronary revascularization (CR) is unknown. We compared this new hybrid method with all-nuclear/all-CMR methods in the assessment of viable myocardium and in downstream referral to CR.Patients and methods
Overall, 12 patients with rest perfusion defects on a single photon emission computed tomography (SPECT) were recruited for cardiac viability assessment using a PET/MRI device. Perfusion (SPECT and CMR), metabolism, late gadolinium enhancement (LGE), and contractility were compared using a 20-segments bull’s eye for agreement. The patterns of ischemia/viability were compared between all-nuclear, all-CMR, and hybrid methods. Downstream CR was proposed after correlating findings to coronary angiography.Results
The SPECT and CMR perfusion denoted poor agreement [agreement rate (AR): 60%; κ: 0.191, P<0.004]. The added PET metabolism concurred in reclassifying 19.2% of segments with intermediate or unassessable LGE using the hybrid method. Overall, the all-CMR method showed better agreement with the hybrid method than the all-nuclear method for findings of normal (AR: 100%, κ: 1.00 vs. 65.8% %; κ: 0.347, respectively; P<0.001), scar (AR: 85%; κ: 0.675 vs. 80.8%; κ: 0.596, respectively; P<0.001), and ischemic segments (AR: 95.8%; κ: 0.881 vs. 75.8%; κ: 0.168, respectively; P<0.001). Downstream CR was proposed in four, 11, and 12 vessels by the all-nuclear, all-CMR, or hybrid methods, respectively.Conclusion
Compared with all-CMR, the hybrid method allowed the reclassification of 19.2% segments. Using CMR perfusion instead of SPECT perfusion had a significant impact on downstream target vessel revascularization.