title: Magnetic resonance imaging of the alar and transverse ligaments in acute whiplash-associated disorders 1 and 2: a cross-sectional controlled study.
abstract: METHODS
  Cross-sectional.
  
  
  OBJECTIVE
  To describe alar- and transverse-ligament magnetic resonance imaging (MRI) high-signal changes in acute whiplash-associated disorders (WAD) grades 1 and 2 in relation to the severity and mechanics of trauma, and to compare them with controls.
  
  
  BACKGROUND
  The alar and transverse ligaments are important stabilizers at the craniovertebral junction. Acute injury of these ligaments should be detected as high-signal changes on high-resolution MRI.
  
  
  METHODS
  In the study, 114 consecutive acute WAD 1-2 patients and 157 noninjured controls underwent upper-neck high-resolution MRI, using proton-weighted sequences and Short Tau Inversion Recovery (STIR). Two blinded radiologists independently graded high-signal changes 0 to 3 on proton images and assessed ligament high-signal intensity on STIR. Image quality was evaluated as good, reduced, or poor (not interpretable). Multiple logistic regression was used for both within- and between-groups analyses.
  
  
  RESULTS
  All proton and STIR images were interpretable. Interobserver agreement for grades 2 to 3 versus grades 0 to 1 changes was moderate to good (κ = 0.71 alar; and 0.54 transverse). MRI showed grades 2 to 3 alar ligament changes in 40 (35.1%) and grades 2 to 3 transverse ligament changes in 27 (23.7%) of the patients. Such changes were related to contemporary head injury (P = 0.041 alar), neck pain (P = 0.042 transverse), and sex (P = 0.033 transverse) but did not differ between patients and controls (P = 0.433 alar; and 0.254 transverse). STIR ligament signal intensity, higher than bone marrow, was found in only three patients and one control.
  
  
  CONCLUSIONS
  This first study on high-resolution MRI of craniovertebral ligaments in acute WAD 1-2 indicates that such trauma does not induce high-signal changes. Follow-up studies are needed to find out whether pretraumatic high-signal changes imply reduced ligament strength and can predict chronic WAD.
authors.affiliation: Department of Radiology, Haukeland University Hospital, Bergen, Norway. nils.vetti@helse-bergen.no
authors.forename: Nils
authors.initials: N
authors.lastname: Vetti
authors.forename: Jostein
authors.initials: J
authors.lastname: Kråkenes
authors.forename: Eivind
authors.initials: E
authors.lastname: Damsgaard
authors.forename: Jarle
authors.initials: J
authors.lastname: Rørvik
authors.forename: Nils Erik
authors.initials: NE
authors.lastname: Gilhus
authors.forename: Ansgar
authors.initials: A
authors.lastname: Espeland
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008022:Ligaments / Q000000981:diagnostic imaging* / Q000293:injuries*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011859:Radiography; D014911:Whiplash Injuries / Q000175:diagnosis*; D055815:Young Adult