Brain MRI Findings in Children with Acute Lymphoblastic Leukemia

Background: Patients with leukemia are facing more complications in order to achieve longer survival. We aimed to evaluate the frequency of central nervous system abnormalities (CNS) on MRI of children with acute lymphoblastic leukemia (ALL). Methods: Sixty-six children with diagnosis of ALL aged 2-18 years were recruited. Non-contrast sequences of brain MRI in addition to diffusion weighted imaging of brain were obtained with 1.5 T (Siemens medical system) scanners in their maintenance phase of treatment. The age of onset, type of leukemia, protocol of treatment, and elapsed time from diagnosis were recorded. Chi-square test was used to compare the groups and t-test was used to evaluate the effect of not normally distributed variables. Results: 19 (28.8%) had abnormal CNS findings identified on MRI images including: nonspecific white matter high signal intensity in flair images with normal DWI, white matter ischemia proved on DWI, generalized brain atrophy, isolated mild enlargement of lateral ventricle and extracerebral complications including sinus thrombosis and sinusitis. Brain abnormalities were correlated with leukemia type, chemotherapy protocol and radiotherapy (P=0.006, 0.036, and 0.01, respectively).   Conclusion: The wide spectrum of CNS abnormalities that were observed in children with ALL showed correlation with treatment methods and type of leukemia in this study. Combination of radiation therapy and chemotherapy increased CNS complications. Among extracerebral complications, dural sinus thrombosis proved by MRV was seen more frequently in T-cell leukemia patients treated with multiple high doses of the chemotherapy agent “L-asparaginase”. Since some neurological complications of leukemia are treatable, early diagnosis sounds essential.