CMR Late Enhancement Pericarditis Index (LEPI) Calculator

CMR Late Enhancement Pericarditis Index (LEPI): Explanation and Clinical Context The CMR LEPI is a quantitative tool developed to assess the severity and risk stratification in patients with acute or chronic pericarditis using cardiac magnetic resonance imaging. It integrates three key parameters: pericardial late gadolinium enhancement (LGE) score, pericardial thickness measured on imaging, and pericardial edema detected by T2-weighted sequences. The formula, as proposed in original studies, weights LGE most heavily, followed by thickness and edema: LEPI = (LGE × 0.5) + (Thickness × 0.3) + (Edema × 0.2).

A higher LEPI score correlates with increased risk of adverse outcomes, including recurrent pericarditis, constrictive physiology, or need for escalated anti-inflammatory therapy. This index allows clinicians to objectively quantify disease activity and guide management, especially when traditional clinical assessment is equivocal.