Background: Cardiovascular magnetic resonance (CMR) imaging is a clinically proven and reliable diagnostic method for the assessment of morphology, function, and characteristics of myocardial tissue in patients with myocardial diseases. The use of gadolinium contrast agents has created new diagnostic possibilities for tissue characterisation in patients with suspected or known cardiomyopathy, myocarditis, and cardiac tumours.

Aim: To evaluate the usefulness of CMR in the diagnostic process in children with myocardial diseases and to compare the results of CMR and other non-invasive cardiovascular methods, including echocardiography.

Methods: The study included 112 children, with an average age of 12 ± 4.64 years, with various forms of myocardial disease: 63 children with hypertrophic cardiomyopathy (HCM), 9 with suspected myocarditis, 5 with history of myocarditis, 4 with dilated cardiomyopathy (DCM), 9 with suspected arrhythmogenic right ventricular cardiomyopathy (ARVC), 6 with left ventricular non-compaction cardiomyopathy (LVNC), 9 with suspected restrictive cardiomyopathy (RCM) to be differentiated with constrictive pericarditis (CP), and 7 with cardiac tumours.

Results: CMR confirmed the echocardiographic diagnosis of HCM in 92% of children and ruled it out in 8%, and in three children apical hypertrophy was found. CMR revealed the presence of myocardial fibrosis in 60% of patients with HCM. In 33% of children with clinically suspected myocarditis CMR confirmed this diagnosis, while in 44% of them DCM was recognised. Of the five children with a history of myocarditis, in one patient CMR performed 13 years after myocarditis revealed features of post-inflammatory DCM. In 75% of patients with the echocardiographic diagnosis of post-inflammatory DCM the result of CMR was consistent. CMR ruled out the presence of ARVC in 89% of children. Echocardiographic and CMR diagnosis of LVNC was consistent in 67% of children. CMR confirmed the clinical diagnosis of RCM in 63% of patients, and in one patient CP was recognised. CMR confirmed the presence of cardiac tumour in 57% of children and excluded it in 43% of patients.

Conclusions: CMR is increasingly recognised as an important tool in the investigation of myocardial disease and should be part of routine clinical work-up. CMR provides an additional diagnostic technique to assess the presence or exclusion of an active myocarditis. In children with clinical and echocardiographic suspicion of LVNC, ARVC, RCM, CP, and cardiac tumours CMR can conclusively confirm the presence of the disease.