Additional value of hybrid PET/MR imaging versus MR or PET performed separately to assess cardiovascular disease.

Introduction And Objectives: Hybrid positron emission tomography (PET) and magnetic resonance (MR) imaging is an emerging technology in the diagnosis of cardiovascular disease; however, there have been no reports of its use in the national clinical setting. Our objective was to evaluate the additional value of integrated PET/MR systems compared with MR and PET performed separately in this setting.

Methods: We prospectively included 49 patients, 30 to assess myocardial viability (coronary group) and 19 to assess inflammatory, infectious, and tumoral diseases (noncoronary heart disease group). All patients underwent cardiac F-fluorodeoxyglucose PET/MR. PET/MR studies included attenuation correction sequences, followed by simultaneous cardiac PET and cardiac MR acquisition, with protocols adapted to the clinical indication (cine, tissue characterization and/or late enhancement imaging).

Results: Most (87.8%) PET/MR studies were initially interpretable. Use of PET/MR improved diagnosis vs PET or MR performed separately in 42.1% of coronary cases and 88.9% of noncoronary cases. PET/MR enabled reclassification of 87.5% of coronary cases initially classified as showing inconclusive results on MR or PET and 70% of noncoronary cases.

Conclusions: In our series, multimodality PET/MR technology provided additional diagnostic value in some patients with cardiovascular disease compared with MR and PET performed separately, especially in cases of noncoronary heart disease and in those with inconclusive results on MR or PET. In our experience, the main benefits of PET/MR include the possibility of simultaneous acquisition, the in vivo integration of anatomical/functional/metabolic aspects, and the interaction of different experts in imaging modalities.