Brain and spinal cord MRI of acute enhancing lesions due to multiple sclerosis

(A) On axial brain MRI, actively inflamed MS lesions demonstrate enhancement on post-contrast T1-weighted images, often incomplete ring with the opening pointing to the cortex (arrows). Complete rings as well as solid patterns of enhancement (dashed arrow) are also common. Similar patterns of enhancement can be seen in the spinal cord.

(B) Sagittal MRI of the spinal cord demonstrates a ring-enhancing cervical cord lesion in a patient with MS. Damage to the spinal cord is one of the major reasons for MS-related disability. While brain lesions may be clinically silent, this is rarely the case for spinal cord lesions, which can cause significant weakness, sensory symptoms, and/or bowel and bladder dysfunction. As in the brain, these lesions are typically discrete plaques within the white matter of the spinal cord. Over time, they may become more confluent. On axial cord imaging (not shown), MS lesions are typically eccentric within the cord and do not occupy the entire spinal cord.