Inclusion criteria:  Age under 25 y.o.; A history of transfusion-dependent anemia of various origins. indications for the appointment of chelation therapy  Non-inclusion criteria:  Age over 25 y.o. The number of RBC transfusions previously received by the patient is less than 10  Exclusion criteria:  Absolute contraindications to magnetic resonance imaging (pacemaker, ferromagnetic implants, etc.); Refusal to sign the informed consent.