"The sign describes the involvement of the spinal cord as seen on axial T2 sequences in patients with myelitis, whereby there is a round hyperintense lesion with a hypointense central core 1-4. There may or may not be peripheral post-gadolinium enhancement, and the ring may or may not be complete 1-4. Overall, this gives the appearance to that of a bagel 1-4. On sagittal sequences, lesions with the bagel sign often demonstrate features of a longitudinally extensive transverse myelitis 1."