Purpose or Case Report: Learning objectives:
1.Review the main pediatric cardiomyopathy phenotypes.
2.Clarify the role of MRI across the care pathway.
3.Walk through the key MRI sequences we actually use in kids.
4.Recognize the essential imaging findings that help us differentiate among them.

- Introduction:
Pediatric cardiomyopathies are a rare heterogeneous group of myocardial diseases but are the first cause of heart transplantation in children.
Causes are diverse—genetic mutations, coronary anomalies, infections, toxins, arrhythmias—and sorting out phenotypes can be tricky because adult criteria are often not applicable to kids and because many kids don’t tolerate long exams.

- Imaging techniques:
Echocardiography represents the first first-line modality but it is often complemented with CMR as it allows a radiation-free differentiation between different phenotypes with unique myocardial tissue characterization, playing a key role in diagnosis, risk stratification, and treatment assessment.

- Key MRI sequences:
Conventional cardiomyopathies protocols in children may use 1.5 or 3 Tesla field strengths and include the following sequences:
Initial localizers.
Cine imaging.
Phase contrast.
Parametric mapping.
LGE.

- Dilated Cardiomyopathy:
Most common.
Leading cause of heart transplant.
Dilated chambers.
Reduced systolic function.
LGE: Patchy or longitudinal mid-wall, transmural, subepicardial, or diffuse subendocardial involvement. Presence of LGE indicates poor prognosis and increased risk of SCD.
Native T1 mapping is suggested to be the strongest independent predictor of diffuse myocardial disease, allowing for the identification of patients at risk for adverse outcomes.

- Hypertrophic Cardiomyopathy:
2nd most common.
LV hypertrophy z-score >2.5 (no family history) or >2 (with family history/genetic test).
LVOT obstruction and SAM.
LGE: Independent risk factor for SCD.
Differential diagnosis with athlete's heart.

- Arrhythmogenic Cardiomyopathy:
RV and/or LV dilatation and reduced EF.
Wall motion abnormalities – most important finding in kids.
Myocardial fibrosis.
Fatty infiltration rare in children.

- Restrictive Cardiomyopathy:
Rarest CMP.
Non-dilated biventricular failure and biatrial dilatation.
Ddx: constrictive pericarditis.

- Excessive trabeculation/NCCM:
Non-compacted/Compacted myocardium ratio > 2.3 measured in diastole.
In the absence of dilation or systolic dysfunction, can be considered a phenotypic trait not necessarily associated with CMP.
Methods & Materials:
Results:
Conclusions: