Table 1. A summary of the original (2009)39 and revised (2018)12 Lake Louise criteria.
| Lake Louise criteria |
| Lake Louise Criteria (2009)39: |
| In the setting of clinically suspected myocarditis, CMR findings are consistent with myocardial inflammation if at least 2 of the following 3 criteria are present: |
| - Regional or global myocardial SI increase in T2-weighted images (edema) |
| - Increased global myocardial early gadolinium enhancement ratio between myocardium and skeletal muscle in gadolinium-enhanced T1-weighted images (hyperemia) |
| - At least 1 focal lesion with nonischemic regional distribution in inversion recovery-prepared gadolinium-enhanced T1-weighted images (*LGE*) (necrosis/fibrosis) |
| The presence of LV dysfunction or pericardial effusion provides additional, supportive evidence or myocarditis. |
| Updated Lake Louise criteria (2018)12: |
| Any 2 out of 2 are present: |
| - T2-based imaging: regional high T2 SI or Global T2 SI ratio ≥ 2.0 in T2W CMR images or Regional or global increase of myocardial T2 relaxation time |
| - T1-based imaging: regional or global increase of native myocardial T1 or ECV or areas with high SI in a nonischemic distribution pattern in LGE images |
| Supportive criteria: |
| - Pericardial effusion in cine CMR images or High signal intensity of the pericardium in LGE images, T1-mapping or T2-mapping |
| - Systolic LV wall motion abnormality in cine CMR images |
CMR = cardiac magnetic resonance LGE = late gadolinium enhancement LV = left ventricle
SI = signal intensity T2W = T2-weighted ECV = extracellular volume