Avanto 1.5t mri unit

Magnetic resonance imaging of the brain and spinal cord was performed by a Siemens Avanto 1.5T MRI unit (Siemens, Germany), and MRI results were evaluated by a pediatric neurologist and a radiologist who were blinded to the clinical diagnosis. MRI scans included T1-axial, T2-axial, T2-sagittal, fluid-attenuated inversion recovery (FLAIR)-axial, and diffusion-weighted imaging (DWI). The lesion location of the brain and spinal cord was classified as white matter (such as subcortical and paraventricular), corpus callosum, optic nerve, thalamus, basal ganglia, cerebellum, brainstem, cortical area, and spinal cord. Typical cerebral and spinal cord lesions were defined according to the previous reports (15 (link), 16 (link)).

All patients received cerebral and spinal cord MRI with the Siemens Avanto 1.5T MRI unit (Siemens AG, Erlangen, Germany) or the GE750 Discovery 3T MRI unit (GE Healthcare, Waukesha, WI, USA). Cerebral MRI included axial T1, T2, T2 fluid-attenuated inversion recovery, diffusion-weighted and sagittal T1 images of the brain. Spinal cord MRI included sagittal T1, T2, T2 fat-suppressed and axial T2 fat-suppressed images of the spinal cord. Intravenous contrast was used in most patients. All MRI studies were evaluated by a radiologist and a senior pediatric neurologist (JS and LZ, respectively), who were blinded to the clinical diagnosis of the patients before immunotherapy, and by a third rater (SZ) in instances of discordant results. Cerebral and spinal lesion locations were the supratentorial white matter (e.g., juxtacortical, non-juxtacortical, and non-periventricular white matter, periventricular white matter, and corpus callosum), thalamus/basal ganglia, brainstem, cerebellum, or myelin with and without LETM (which was defined as spinal cord lesions extending over three or more vertebral levels on sagittal spinal MRI) (2 (link)). A typical cerebral MRI was defined as blurred/hazy, large (i.e., ≥2 cm on the axial sequence) lesions in the aforementioned anatomical locations (13 (link)).