Table 3.

Updated Lake Louise Criteria.

Main criteria (“2 out of 2”)

T2-based imaging ○Regional * high T2 signal intensity or ○Global T2 signal intensity ratio ≥2.0 in T2-weighted images or ○Regional or global increase of myocardial T2 relaxation times ** T1-based imaging ○Regional or global increase of native myocardial T1 relaxation times or extracellular volume *** or ○Areas with high signal intensity in a non-ischemic distribution pattern in late gadolinium enhancement images

Supportive criteria

Pericardial inflammation ○Pericardial effusion in cine images or ○High signal intensity of the pericardium on late gadolinium enhancement images and/or T1 mapping and/or T2 mapping Left ventricular dysfunction ○Systolic left ventricular wall motion abnormality in cine images

* Regional refers to an area of at least 10 continuous pixels. ** Published or local normal values. *** T1 mapping is highly sensitive to detecting both acute and chronic forms of increased free water content within the myocardium, and thus is considered as an alternative criterion to early gadolinium enhancement. If paired with late gadolinium enhancement to diagnose myocarditis, the areas of T1 abnormality should be beyond that detected by late gadolinium enhancement. Adapted and modified with permission from Ferreira et al. [7].