The study is aimed at assessing changes in the brain of patients from 6 to 18 years old with a diagnosis of acute lymphoblastic leukemia during chemotherapy.

Children with acute lymphoblastic leukemia receive long-term combined chemotherapy treatment, one of the main part of this treatment is methotrexate. Methotrexate can cause acute, subacute, and long-term neurotoxicity. Clinical symptoms of neurotoxicity, such as seizures, aphasia, are often associated with leukoencephalopathy. However, leukoencephalopathy may develop asymptomatically in children receiving methotrexate.

The effect of chemotherapy on the neurological status of patients is widely covered in the literature. There are very few studies devoted to the quantitative assessment of MRI parameters, especially in children. MRI is a non-invasive method that does not harm the patient and can be used to assess absolutely all structures of the brain.

Inclusion Criteria:

1. patients from 6 to 18 years old
2. diagnosis of acute lymphoblastic leukemia during chemotherapy

Exclusion Criteria:

1. patients less then 6, and older then 18 years old
2. patients who cannot perform the study MRI without general anesthesia
3. Refusal to sign informed consent.
4. The presence of absolute contraindications to MRI studies.
5. Extremely serious condition of the patient.