Cardiac MRI Assessment of Nonischemic Myocardial Inflammation: State of the Art Review and Update on Myocarditis Associated with COVID-19 Vaccination

Abstract

Myocarditis is a nonischemic inflammatory disease of the myocardium that can be triggered by a multitude of events, including viral infection and toxins. Recently, there has been heightened interest in myocarditis given its association with COVID-19 vaccination. Timely identification of myocarditis can affect patient management and prognosis. Therefore, it is crucial for radiologists and cardiac imagers to understand the role of cardiac imaging to establish a diagnosis and inform treatment decisions. Cardiac MRI is the most important noninvasive imaging modality for evaluation of myocarditis, with typical findings of focal or diffuse myocardial edema and myocardial damage, including presence of late gadolinium enhancement. There are currently limited data available to indicate that the pattern of myocardial injury following COVID-19 vaccination is similar to other causes of myocarditis, although the severity of disease may be relatively mild. A description of the role of imaging and typical imaging features will be reviewed here, with a focus on emerging data in the setting of myocarditis after COVID-19 vaccination. Keywords: MRI, Heart, Inflammation © RSNA, 2021

Combined Cardiac Fluorodeoxyglucose–Positron Emission Tomography/Magnetic Resonance Imaging Assessment of Myocardial Injury in Patients Who Recently Recovered From COVID-19

“…However, longer-term follow-up studies are required to understand the need for ongoing cardiac surveillance, relationship to cardiac symptoms, guidance for safe return to exercise and sports participation, and long-term cardiovascular disease risk. 27 There are limited data regarding blood biomarkers in patients who have recovered from COVID-19 and their association to myocardial abnormalities. One prior study described elevations in hsTnI at the time of imaging 6 while others have not.…”

COVID-19 Cardiovascular Connection: A Review of Cardiac Manifestations in COVID-19 Infection and Treatment Modalities

“…Diagnosis of myocarditis can be challenging in patients presenting with acute coronary syndromes (ACS). Differentiating features are usually associated with echocardiographic evidence of global hypokinesis rather than focal wall motion abnormalities seen in ACS 41 .…”

“…Cardiac magnetic resonance imaging (cMRI) is the gold standard imaging modality for diagnosing myocarditis and is useful in differentiating myocarditis from other etiologies of acute chest pain 41 . In those with severe COVID-19 infection, obtaining a definitive diagnosis via cMRI may not be plausible and thus the true prevalence of COVID-19 associated myocarditis is likely underestimated 42 .…”

Combined simultaneous FDG-PET/MRI with T1 and T2 mapping as an imaging biomarker for the diagnosis and prognosis of suspected cardiac sarcoidosis

“…We have shown that FDG-PET/MRI provides complementary information in patients with suspected cardiac sarcoidosis, combining the strengths of both imaging modalities in a single comprehensive study that allows for co-registration of accurate and strongly prognostic imaging data. Key strengths of each imaging modality include characterization of myocardial tissue and quantification of ventricular function on MRI and assessment of metabolic processes such as inflammation on PET (Sanchez Tijmes et al 2021 ). Focal FDG uptake on PET and elevated T2 on MRI had the highest diagnostic specificity among the individual imaging parameters evaluated and are most useful in ruling in cardiac sarcoidosis when present.…”