Patient selection: clinically suspected myocarditis
Criteria - the presence of >= 2 of the following indicate myocardial inflammation:
(1) increase in regional or global myocardial signal intensity in T2-weighted images
(2) increase in global myocardial early gadolinium enhancement ratio (between myocardium and skeletal muscle) in gadolinium-enhanced T1-weighted images
(3) >= 1 focal lesion in a nonischemic regional distribution with late gadolinium enhancement (in inversion recovery-prepared gadolinium-enhanced T1-weighted images)
Additional support evidence of myocarditis:
(1) left ventricular dysfunction
(2) pericardial effusion
If the third criterion is present, then there is evidence of myocyte injury and/or scar caused by myocardial inflammation.
(If one of the criteria is present) OR (if no criteria are present AND onset of symptoms is very recent) then repeat the CMR in 1-2 weeks.
