International Journal of Cardiology

ISSN 2996-8215

International Journal of Cardiology | Vol. 6, No. 5, May 2015 | pp. 33–40

DOI: 10.46882/2015/IJC/000074

Review Article

The Growing Role of Advanced Cardiac Magnetic Resonance Parametric Mapping in Evaluating Myocarditis

Sarah L. Jenkins¹, David M. Ross²

¹Department of Cardiovascular Sciences, British Heart Foundation Centre, King's College London, London, United Kingdom

²Division of Cardiology, Alfred Hospital, Monash University, Melbourne, Victoria, Australia

Abstract:
Acute myocarditis presents with highly variable clinical phenotypes, complicating definitive diagnostic stratification. Traditional cardiac magnetic resonance (CMR) imaging pathways relying on the Lake Louise Criteria offer reasonable diagnostic accuracy but lack sensitivity for diffuse interstitial changes or subtle inflammatory resolution tracking. This systematic review synthesizes recent clinical data regarding the utility of quantitative CMR parametric T1 and T2 mapping methods for diagnosing and monitoring suspected acute myocarditis. A comprehensive database search identified 34 clinical trials involving a combined sample of 2,840 individuals. Quantitative T2 mapping holds exceptional accuracy for detecting localized myocardial edema, showing a pooled sensitivity of 88.0% (95% CI: 83.2%–91.8%) and a specificity of 91.2% (95% CI: 86.5%–94.7%) against endomyocardial biopsy findings. Native T1 mapping and calculated extracellular volume (ECV) fractions successfully quantify diffuse interstitial fibrosis and remodeling that occur secondary to continuous cellular inflammation. Elevated native T1 values provide an adjusted hazard ratio of 2.15 (95% CI: 1.42–3.26, p < 0.01) for predicting 6-month major adverse cardiovascular events (MACE). Quantitative T1 and T2 mapping techniques markedly enhance the diagnostic specificity of CMR for acute myocarditis, offering non-invasive markers to track active inflammatory expansion and refine clinical risk prediction.

Keywords: Myocarditis, Cardiac magnetic resonance, T1 mapping, T2 mapping, Extracellular volume fraction, Myocardial edema, Inflammation

Received: February 14, 2015; Revised: March 28, 2015; Accepted: April 15, 2015; Published: May 20, 2015