Spinal cord ring enhancement in multiple sclerosis.

OBJECTIVE To describe the clinical and imaging characteristics of spinal cord ring enhancement in multiple sclerosis (MS). DESIGN Clinical case series. SETTING Academic referral center. PATIENTS Twenty patients with MS who had spinal cord ring enhancement were retrospectively identified from 322 cervical and thoracic spinal cord magnetic resonance imaging studies during a 3-year period. MAIN OUTCOME MEASURES Demographics, disability, and pattern of enhancement on spinal cord and concomitant brain magnetic resonance imaging results. RESULTS Ring enhancement was seen in 20 patients with spinal cord enhancement, most commonly in the cervical cord. Incomplete or "open" ring enhancement was the dominant pattern in 19 of the 20 patients (95%). Concurrent enhancing brain lesions were present in 14 patients, 8 of which (57%) exhibited a ring pattern of enhancement. At the time of imaging, the Expanded Disability Status Scale scores ranged from 1.0 to 7.0 (median score, 3.0). CONCLUSIONS Ring enhancement is not an uncommon pattern for spinal cord lesions in MS, occurring with a prevalence of 6.2% (20 of 322 imaging studies). The most common pattern is incomplete ring enhancement in the cervical spinal cord. Recognition of this pattern may improve and expedite the diagnosis of MS and preclude the need for invasive diagnostic interventions.