Table 7.

Proposed diagnostic CMR criteria (Lake Louise Consensus Criteria) for myocarditis

In the setting of clinically suspected myocarditisa, CMR findings are consistent with myocardial inflammation, if at least two of the following criteria are present: Regional or global myocardial SI increase in T2-weighted imagesb.□ Increased global myocardial early gadolinium enhancement ratio between myocardium and skeletal muscle in gadolinium-enhanced T1-weighted imagesc.□ There is at least one focal lesion with non-ischemic regional distribution in IR-prepared gadolinium-enhanced T1-weighted images (”late gadolinium enhancement”)d. A CMR study is consistent with myocyte injury and/or scar caused by myocardial inflammation, if - criterion 3 is present.

A repeat CMR study between 1 and 2 weeks after the initial CMR study is recommended, if - none of the criteria are present, but the onset of symptoms has been very recent and there is strong clinical evidence for myocardial inflammation. - one of the criteria is present.

The presence of LV dysfunction or pericardial effusion provides additional, supportive evidence for myocarditis.

^aThe clinical suspicion for active myocarditis should be based on the criteria listed in table 5.

^bImages should be obtained using a body coil or a surface coil with an effective surface coil intensity correction algorithm; global SI increase has to be quantified by an SI ratio of myocardium over skeletal muscle of ≥2.0). If the edema is more subendocardial or transmural in combination with a co-localized ischemic (including the subendocardial layer) pattern of late gadolinium enhancement, acute myocardial infarction is more likely and should be reported.

^cImages should be obtained using a body coil or a surface coil with an effective surface coil intensity correction algorithm; a global SI enhancement ratio of myocardium over skeletal muscle of ≥4.0 or an absolute myocardial enhancement of ≥45% is consistent with myocarditis.

^dImages should be obtained at least 5 minutes after gadolinium injection; foci typically exclude the subendocardial layer, are often multi-focal, and involve the subepicardium. If the late gadolinium enhancement pattern clearly indicates myocardial infarction and is co-localized with a transmural regional edema, acute myocardial infarction is more likely and should be reported.