T1 and T2 mapping in myocarditis: seeing beyond the horizon of Lake Louise criteria and histopathology.

INTRODUCTION: Myocarditis and its sequelae remain an unconquered clinical problem, disproportionately affecting the young. Several hurdles beset myocarditis, including non-specific symptoms, heterogeneous clinical presentation, dynamic disease stages, underscored by an absence of an easy diagnostic test or a specific treatment. Areas covered: The current diagnostic means are poorly equipped to counter the challenge; the gold standard by invasive endomyocardial biopsy relies on availability of expert procedural and reading skill. The tissue diagnostic criteria were developed to improve readers agreement with clinical diagnosis, and not based on evidence for differential treatment or improved prognosis. The Lake-Louise Criteria represented a first step towards a non-invasive diagnosis. They require extensive imaging, which is insufficiently robust with poor diagnostic confidence and tissue pathophysiological validation; they similarly lack evidence of improved outcome by guiding clinical management. T1 and T2 mapping are a step-change, providing robust, short and quantifiable imaging application, which can veritably reflect the dynamic and heterogeneous underlying disease. Expert commentary: T1 and T2 mapping harbours a unique potential for an objective non-invasive disease recognition and treatment discovery in myocarditis. These measures should enter independently into clinical experimentation, with a high priority for outcome and therapeutic studies.