LGE Extent (% Myocardium Scarred): Explanation and Clinical Context LGE (Late Gadolinium Enhancement) imaging by cardiac MRI allows quantification of myocardial scar tissue, expressed as a percentage of total left ventricular (LV) myocardial mass.
The LGE extent is calculated as (Scar Mass / Total LV Myocardial Mass) × 100.
Low values (0–5%) represent minimal or no fibrosis, while higher percentages indicate significant myocardial scarring.
Clinically, LGE extent correlates with adverse cardiovascular outcomes, including arrhythmias, heart failure progression, and mortality risk.
Patients with LGE >15% of LV mass are at higher risk for major adverse cardiac events (MACE) and may benefit from closer monitoring or device therapy.
This tool provides a rapid, quantitative assessment for clinicians to stratify risk and guide management decisions.
Reference:
Kim RJ, Wu E, Rafael A, Chen EL, Parker MA, Simonetti O, Klocke FJ, Bonow RO, Judd RM. The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction. N Engl J Med. 1999;343:1445–1453. doi:10.1056/NEJM199911183432003