RESUMEN
<p><b>OBJECTIVE</b>To investigate the changes in brain injury after the induction chemotherapy in children with acute lymphoblastic leukemia (ALL) by cranial MRI.</p><p><b>METHODS</b>The clinical data and cranial MRI results of 62 children with ALL who were hospitalized from March 2014 to June 2015 were analyzed retrospectively.</p><p><b>RESULTS</b>Before chemotherapy, MRI showed bone marrow infiltration of the skull in 33 patients (53%); the children with WBC<20×10(9)/Lhad a significantly lower incidence rate of bone marrow infiltration of the skull than those with WBC≥20×10(9)/L (16 patients/42% vs 17 patients/71%; P<0.05), and the high-risk group had a significantly higher incidence rate of bone marrow infiltration of the skull than the non-high-risk group (71% vs 44%; P<0.05). Before chemotherapy, there were 4 cases (7%) of brain atrophy, and 2 cases (3%) of abnormal signals in the sensory conduction bundle. MRI reexamination in 28 patients after 3 months of chemotherapy showed 3 new cases (11%) of brain atrophy and 1 aggravated case of brain atrophy.</p><p><b>CONCLUSIONS</b>The children with ALL have bone marrow infiltration of the skull, brain atrophy, and abnormal signals in the sensory conduction bundle before chemotherapy, especially bone marrow infiltration of the skull, and some changes in brain injury disappear after treatment.</p>