The purpose of our study was to compare diagnostic performance of old and new Lake Louise Criteria (oLLC and nLLC) among different clinical presentations: infarct-like (IL), cardiomyopathic (CM) and arrhythmic (AR). 102 patients with clinical suspicion of acute myocarditis underwent cardiac magnetic resonance (CMR) on a 1.5 T scanner. Protocol included cine-SSFP, T2-weighted STIR, T2 mapping, early and late gadolinium enhancement and T1 mapping acquired before and after gadolinium administration. The degree of agreement has been calculated with Cohen’s K test. 42 patients also underwent endomyocardial biopsy (EMB). IL onset was present in 54/102 patients, CM in 28/102 and AR in 20/102. nLLC were positive in 58.3% of the patients, while oLLC in 37.9%, k = 0.57 (IC: 0.428–0.713). The degree of agreement between nLLC and oLLC was 0.49 (IC: 0.111–0.876) for AR onset (nLLC positive in 35% vs oLLC in 15%), 0.25 (IC: 0.035–0.459) for CM pattern (nLLC positive in 60.7% vs oLLC 17.9%) and 0.73 (IC: 0.543–0.912) for IL presentation (nLLC positive in 66.7% vs oLLC in 57.4%). Diagnostic accuracy was 75% for both nLLC and oLLC among IL onset, and 41.6% for oLLC vs 66.7% for nLLC, as regards CM clinical presentation. nLLC have improved diagnostic performance of CMR for the diagnosis of acute myocarditis, in particular for atypical clinical presentation.

Early detection of myocardial involvement can be relevant in coronavirus disease 2019 (COVID-19) patients to timely target symptomatic treatment and decrease the occurrence of the cardiac sequelae of the infection. The aim of the present study was to assess the clinical value of cardiovascular magnetic resonance (CMR) in characterizing myocardial damage in active COVID-19 patients, through the correlation between qualitative and quantitative imaging biomarkers with clinical and laboratory evidence of myocardial injury. In this retrospective observational cohort study, we enrolled 27 patients with diagnosis of active COVID-19 and suspected cardiac involvement, referred to our institution for CMR between March 2020 and January 2021. Clinical and laboratory characteristics, including high sensitivity troponin T (hs-cTnT), and CMR imaging data were obtained. Relationships between CMR parameters, clinical and laboratory findings were explored. Comparisons were made with age-, sex- and risk factor–matched control group of 27 individuals, including healthy controls and patients without other signs or history of myocardial disease, who underwent CMR examination between January 2020 and January 2021. The median (IQR) time interval between COVID-19 diagnosis and CMR examination was 20 (13.5–31.5) days. Hs-cTnT values were collected within 24 h prior to CMR and resulted abnormally increased in 18 patients (66.6%). A total of 20 cases (74%) presented tissue signal abnormalities, including increased myocardial native T1 (n = 11), myocardial T2 (n = 14) and extracellular volume fraction (ECV) (n = 10), late gadolinium enhancement (LGE) (n = 12) or pericardial enhancement (n = 2). A CMR diagnosis of myocarditis was established in 9 (33.3%), pericarditis in 2 (7.4%) and myocardial infarction with non-obstructive coronary arteries in 3 (11.11%) patients. T2 mapping values showed a moderate positive linear correlation with Hs-cTnT (r = 0.58; p = 0.002). A high degree positive linear correlation between ECV and Hs-cTnT was also found (r 0.77; p < 0.001). CMR allows in vivo recognition and characterization of myocardial damage in a cohort of selected COVID-19 individuals by means of a multiparametric scanning protocol including conventional imaging and T1–T2 mapping sequences. Abnormal T2 mapping was the most commonly abnormality observed in our cohort and positively correlated with hs-cTnT values, reflecting the predominant edematous changes characterizing the active phase of disease.

Four-dimensional (4D) flow MRI has emerged as a powerful non-invasive technique in cardiovascular imaging, enabling to analyse in vivo complex flow dynamics models by quantifying flow parameters and derived features. Deep knowledge of aortic flow dynamics is fundamental to better understand how abnormal flow patterns may promote or worsen vascular diseases. In the perspective of an increasingly personalized and preventive medicine, growing interest is focused on identifying those quantitative functional features which are early predictive markers of pathological evolution. The thoracic aorta and its spectrum of diseases, as the first area of application and development of 4D flow MRI and supported by an extensive experimental validation, represents the ideal model to introduce this technique into daily clinical practice. The purpose of this review is to describe the impact of 4D flow MRI in the assessment of the thoracic aorta and its most common affecting diseases, providing an overview of the actual clinical applications and describing the potential role of derived advanced hemodynamic measures in tailoring follow-up and treatment.

The restrictive cardiomyopathies constitute a heterogeneous group of myocardial diseases with a different pathogenesis and overlapping clinical presentations. Diagnosing them frequently poses a challenge. Echocardiography, electrocardiograms and laboratory tests may show non-specific changes. In this context, cardiac magnetic resonance (CMR) may play a crucial role in defining the diagnosis and guiding treatments, by offering a robust myocardial characterization based on the inherent magnetic properties of abnormal tissues, thus limiting the use of endomyocardial biopsy. In this review article, we explore the role of CMR in the assessment of a wide range of myocardial diseases causing restrictive patterns, from iron overload to cardiac amyloidosis, endomyocardial fibrosis or radiation-induced heart disease. Here, we emphasize the incremental value of novel relaxometric techniques such as T1 and T2 mapping, which may recognize different storage diseases based on the intrinsic magnetic properties of the accumulating metabolites, with or without the use of gadolinium-based contrast agents. We illustrate the importance of these CMR techniques and their great support when contrast media administration is contraindicated. Finally, we describe the useful role of cardiac computed tomography for diagnosis and management of restrictive cardiomyopathies when CMR is contraindicated.