Figure 1. MS-like (‘green flag’) and NMOSD-like (‘red flag’) MRI features of the patient. (A) Axial fluid-attenuated inversion recovery (FLAIR): Oval/round lesions, asymmetrical distribution, abutting and perpendicular to the lateral ventricles without infiltrating the white matter (MS-like). (B) Sagittal T1 without contrast: periventricular lesions perpendicular to the corpus callosum (‘Dawson’s fingers’) and black holes (MS-like). (C) Cerebral peduncles (MS-like); (D) Axial FLAIR: periependymal lesions surrounding the lateral ventricles and the third ventricle (NMOSD-like or other nonspecific lesions such as ependymitis granularis). (E) Axial FLAIR: lesions touching or within the cortex (MS-like). (F) Axial FLAIR: lesions around the fourth ventricle (NMOSD-like). (G) Sagittal T2: multiple discrete (focal) short eccentric lesions, ≤2 vertebral segments (MS-like); suspected area postrema lesions (NMOSD-like). (G’) Sagittal T2: follow-up was conducted in the first month after the end of treatment, and new lesions appeared in the cervical spinal cord (MS-like).