Cervical ribs: A common variant overlooked in CT imaging

BACKGROUND AND PURPOSE: Cervical ribs are congenital variants that are known to cause TOS or brachial plexopathy in up to 10% of the affected individuals. We investigated how often cervical ribs are present on cervical spine CT scans to determine the incidence in humans and the percentage of reported cervical ribs. MATERIALS AND METHODS: Cervical spine CT scans and the reports of 3404 consecutive adult patients were retrospectively reviewed to determine the presence of cervical ribs and whether they had been reported. RESULTS: Cervical ribs were found in 2.0% (67/3404) of the population. Of the 67 patients with cervical ribs, 27 (40.3%) had bilateral ribs. The prevalence of cervical ribs in women was twice that in men, 2.8% (39/1414) versus 1.4% (28/1990). Although African Americans accounted for 50.1% (1706/3404) and whites, 41.2% (1402/3404) of the patient population, African Americans were 70.1% (47/67) of patients with cervical ribs, whereas whites were 26.9% (18/67). Radiologists commented on 25.5% (24/94) of the cervical ribs in 25.4% (27/67) of patients. CONCLUSIONS: The prevalence of cervical ribs in the human population has been a source of uncertainty due to the degree of difficulty that comes in detecting this often subtle congenital variation. In our sample, the prevalence was 2.0% of patients. Our study determined that cervical ribs are underreported in patients undergoing cervical spine CT. Given the potential clinical implications of these anatomic variants, neuroradiologists must be more meticulous in identifying cervical ribs when reviewing cervical spine CT scans.