T2 Mapping Edema Index (Myocardial) Calculator

Inputs (all numeric, use dot for decimals) T2 Mapping Edema Index: Explanation and Clinical Context T2 mapping quantifies myocardial transverse relaxation time (T2) in milliseconds on a pixel-wise basis. Elevated myocardial T2 reflects increased free water and serves as a quantitative index of myocardial edema. About the parameters: • T2 (ms): quantitative value representing water content in myocardium. • Z-score: deviation from local normal mean; abnormal if ≥ +2 SD. • Myocardium:Skeletal T2 ratio: internal normalization; interpretation depends on site-specific reference. • T2-weighted SI ratio: historical Lake Louise 2009 parameter; ≥ 2.0 indicates edema.

Clinical interpretation: • Use site-specific thresholds since vendor, field strength, and sequence affect values. • Z-score ≥ +2 supports edema and—combined with a T1-based abnormality (native T1, ECV, or LGE)—meets the updated 2018 Lake Louise criteria for active inflammation. • The SI ratio method remains valid when T2 mapping is unavailable but should be interpreted cautiously.