All patients were investigated using a 3T MRI and 1,5 T MRI scanners. For myocardium, pancreas and pituitary gland iron overload quantification in children we have used special sequences for T2*-mapping.

Miocardium, pancreas and pituitary gland T2* relaxometry maps were calculated automatically by commertial application ReportCARD Functool (GE Healthcare) and integrated Philips T2* maps. Then for selected ROI T2* data acquisition in milisecond [ms] were performed and calculated automatically.

All patients were investigated using a 3T MRI scanner (Philips Achieva) and 1,5 T MRI scanner (GE Signa) with 8-channel surface coil for body scanning. For myocardium, pancreas and pituitary gland iron overload quantification in children we have used special sequences for T2*-mapping based on fast gradient echo sequences - multi-phase fast gradient echo and ultrashort gradient echo (uTE) in axial and coronary plane. For breath-hold acquisition due to failure of communication and invariable behavior some children received anaesthetic support with mechanical ventilation. Miocardium, pancreas and pituitary gland T2* relaxometry maps were calculated automatically by commertial application ReportCARD Functool (GE Healthcare) and integrated Philips T2* maps.

The placement of region of interest (ROI) in target organ were performed by following criterion: for the myocardium - in the interventricular septum in short axis plane; for the pancreas - in corpus in axial plane; for the pituitary gland - in adenohypophysis; for all organs the area of large and small blood vessels, which can introduce distortions of the obtained results were excluded. Then for selected ROI T2* data acquisition in milisecond [ms] were performed and calculated automatically by approximating the attenuation curve with the highest likelihood method.

Inclusion criteria:

1. Age under 25 y.o.;
2. A history of transfusion-dependent anemia of various origins.
3. indications for the appointment of chelation therapy

Non-inclusion criteria:

1. Age over 25 y.o.
2. The number of RBC transfusions previously received by the patient is less than 10

Exclusion criteria:

1. Absolute contraindications to magnetic resonance imaging (pacemaker, ferromagnetic implants, etc.);
2. Refusal to sign the informed consent.