Clinical applications of PET/MR cardiac imaging

The value of positron emission tomography (PET) and magnetic resonance imaging (MRI) in cardiac diseases has been affirmed by the corresponding guidelines of the European Society of Cardiology (ESC). Hybrid PET/MR combines the functional imaging data from PET with those from multiple MRI sequences, the use of which is recommended by clinical consensus in assessing myocardial viability, cardiac masses, cardiac sarcoidosis (CS), myocarditis, and cardiac amyloidosis (CA). This review summarizes recent applications of PET/MR cardiac imaging in coronary heart disease (CHD), cardiomyopathies, cardiac masses, valvular heart disease (VHD) and endocarditis, with an emphasis on CHD and cardiomyopathies. In CHD, PET/MR enables the assessment of high-risk plaques, myocardial perfusion imaging, myocardial viability imaging, and myocardial fibroblast activation imaging. In cardiomyopathies, the applications of PET/MR focus on four specific types of disorders: CA, CS, Anderson-Fabry disease, and myocarditis. In summary, PET/MR can acquire qualitative and quantitative information through a single scan, reflecting multiple dimensions of cardiac status, including morphology, function, perfusion, inflammation, edema, calcification, and fibrosis, thereby facilitating diagnosis and assessment of various cardiac diseases.