[MRI abnormalities of the brain in neurologic complications following treatment of cancer in children].

During a 3-year period, 6 of 50 children with systemic malignacies developed neurologic complications such as hemiparesis, convulsions and loss of consciousness. The children consisted of 1 boy and 5 girls, from 3 to 12 years old, 3 with acute lymphoblastic leukemia and 3 with malignant lymphoma. Four patients received induction treatment that included intravenous administration of L-asparaginase and/or intrathecal administration of methotrexate. One patient received induction treatment and consolidation treatment that included intravenous administration of L-asparaginase. One patient received induction and consolidation treatment, and the protocol for peripheral blood stem cell transplantation. Laboratory examinations revealed coagulation dysfunction in 3 patients treated with L-asparaginase and 1 patient with disseminated intravascular coagulation (DIC). Magnetic resonance imaging (MRI) was performed on a 1.5-T unit, using spin-echo or fast spin-echo sequences. T1-weighted, T2-weighted, and proton density-weighted images were obtained in the axial and/or coronal plane (section thickness, 4 mm; inter-section gap, 2 mm). MRI was initially performed within 36 hours after the onset in all patients, and follow-up MRIs were performed for 6 months. MRI showed lesions involving the cortex and subcortex in 4 patients with coagulation dysfunction. In 2 of these 4 patients, Gd-enhanced T1-weighted images showed contrast enhancement in the surface of the gyrus, suggesting focal vascular stasis. Serial MRI revealed nearly complete resolution of the lesions. Symptoms were relieved in every case. The lesions on MRI were presumed to be due to venous thrombosis related to the coagulation dysfunction caused by L-asparaginase or DIC. On the other hand, in 2 patients with onset after intrathecal administration of high-dose methotrexate and cytarabine, MRI revealed multiple lesions involving the centrum semiovale and periventricular white matter. No Gd-enhancement of the lesion was detected. This MRI finding was consistent with leukoencephalopathy. As time passed, the symptoms improved completely, and the lesions became better demarcated. MRI is useful for differentiating lesions related to coagulation dysfunction from leukoencephalopathy.