Fig. 1

Magnetic resonance imaging of the cervical spinal cord. a. Sagittal T2-weighted imaging showed increased intramedullary signal intensity along the posterior column of the spinal cord extending from C2 to C6 on August 3, 2018. b. A V-shaped hyperintensity on axial T2-weighted imaging at the C4 level was seen within the dorsal cervical spinal cord on August 3, 2018. c. Sagittal T2-weighted imaging showed abnormal, longitudinally and horizontally extensive hyperintensities involving the lateral and posterior columns of the spinal cord extending from C1 through T2 on September 3, 2018. d. Axial T2-weighted imaging at the C4 level showed a ball-shaped hyperintensity on September 3, 2018. e. Sagittal T2-weighted imaging showed hyperintensity along the posterior column of the spinal cord extending from C1 to T1 on October 4, 2018. f. Axial T2-weighted imaging at the C4 level showed that the V-shaped hyperintensity had decreased compared to that in September (d)