Cardiac MRI for Diagnosing Pericarditis and Microvascular Disease

Cardiac MRI Performance for Pericarditis

The American College of Cardiology recommends cardiac MRI for detecting pericardial inflammation with high sensitivity (94-100%), making it an excellent tool to rule out this diagnosis when negative 1
Cardiac MRI demonstrates 94-100% sensitivity for detecting pericardial inflammation, and the ACC/AHA guidelines specifically recommend it when there is diagnostic uncertainty or to determine the presence and extent of pericardial inflammation and fibrosis 1
Cardiac MRI with late gadolinium enhancement (LGE) can show characteristic changes of acute myopericarditis, especially when performed within 2 weeks of presentation 1
Key CMR findings for pericarditis include pericardial enhancement or thickening on LGE sequences, increased T2-weighted signal indicating pericardial edema, and pericardial effusion (though absence doesn't exclude pericarditis) 1

Standard rest CMR without stress perfusion will not detect microvascular dysfunction, and vasodilator stress perfusion CMR would be required to assess for microvascular ischemia, but this is relatively contraindicated in patients with recent or active chest pain 2
The American College of Radiology guidelines note that inotropic stress agents like dobutamine are "relatively contraindicated in patients with recent or active chest pain," limiting stress CMR utility in acute presentations 2
First-pass contrast-enhanced perfusion CMR can demonstrate myocardial perfusion abnormalities, but requires stress challenge to unmask microvascular disease 2, 3

The American College of Cardiology recommends obtaining transthoracic echocardiography first to assess for pericardial effusion, wall motion abnormalities, and valvular issues 1
If echocardiography is inconclusive and pericarditis remains suspected, the American College of Cardiology recommends proceeding with CMR to provide definitive assessment of pericardial inflammation 1
For microvascular disease assessment, the American College of Radiology recommends deferring stress testing until chest pain resolves, and then performing vasodilator stress CMR to evaluate for ischemia 2, 3