Follow-up MR imaging of the alar and transverse ligaments after whiplash injury: a prospective controlled study.

BACKGROUND AND PURPOSE The cause and clinical relevance of upper neck ligament high signal intensity on MR imaging in WAD are controversial. The purpose of this study was to explore changes in the signal intensity of the alar and transverse ligaments during the first year after a whiplash injury. MATERIALS AND METHODS Dedicated high-resolution upper neck proton attenuation-weighted MR imaging was performed on 91 patients from an inception WAD1-2 cohort, both in the acute phase and 12 months after whiplash injury, and on 52 controls (noninjured patients with chronic neck pain). Two blinded radiologists independently graded alar and transverse ligament high signal intensity 0-3, compared initial and follow-up images to assess alterations in grading, and solved any disagreement in consensus. The Fisher exact test was used to compare proportions. RESULTS Alar and transverse ligament grading was unchanged from the initial to the follow-up images. The only exceptions were 1 alar ligament changing from 0 to 1 and 1 ligament from 1 to 0. The prevalence of grades 2-3 high signal intensity in WAD was thus identical in the acute phase and after 12 months, and it did not differ from the prevalence in noninjured neck pain controls (alar ligaments 33.0% versus 46.2%, P = .151; transverse ligament 24.2% versus 23.1%, P = 1.000). CONCLUSIONS Alar and transverse ligament high signal intensity in patients with WAD1-2 observed within the first year after injury cannot be explained by the trauma. Dedicated upper neck MR imaging cannot be recommended as a routine examination in these patients.