title: MRI of the transverse and alar ligaments in rheumatoid arthritis: feasibility and relations to atlantoaxial subluxation and disease activity.
abstract: BACKGROUND
  Dysfunctional transverse and alar craniovertebral ligaments can cause instability and osseous destruction in rheumatoid arthritis (RA). This study examined (1) the feasibility of high-resolution magnetic resonance imaging (MRI) of these ligaments in RA and (2) the relation between ligament high-signal changes and atlantoaxial subluxation and RA duration/severity.
  
  
  METHODS
  Consecutive RA patients (n=46) underwent clinical examination, functional radiography, and high-resolution MRI. Two blinded radiologists rated MRI image quality, graded ligament high-signal changes 0-3 on proton-weighted sequences using an existing grading system, and assessed cervical spine rheumatic changes on short tau inversion recovery images. Agreement was analyzed using kappa and relations using multiple logistic regression.
  
  
  RESULTS
  MRI images had good quality in 42 (91.3%) of 46 patients and were interpretable in 44 (32 women and 12 men, median age/disease duration 60.4/9.1 years). MRI grades 2-3 changes of the transverse and alar ligaments showed moderate and good interobserver agreement (kappa 0.59 and 0.78), respectively, and prevalence 31.8% and 34.1%. Such ligament changes were more frequent with increasing anterior atlantoaxial subluxation (p=0.012 transverse, p=0.028 alar), higher erythrocyte sedimentation rate (p=0.003 transverse), positive rheumatoid factor (p=0.002 alar), and neck pain (p=0.004 alar).
  
  
  CONCLUSIONS
  This first study of high-resolution MRI of these ligaments in RA showed high feasibility and relations with atlantoaxial subluxation, RA disease activity, and neck pain. The clinical usefulness of such MRI needs further evaluation.
authors.affiliation: Department of Radiology, Haukeland University Hospital, Bergen, 5021, Norway. nils.vetti@helse-bergen.no
authors.forename: Nils
authors.initials: N
authors.lastname: Vetti
authors.forename: Rikke
authors.initials: R
authors.lastname: Alsing
authors.forename: Jostein
authors.initials: J
authors.lastname: Kråkenes
authors.forename: Jarle
authors.initials: J
authors.lastname: Rørvik
authors.forename: Nils Erik
authors.initials: NE
authors.lastname: Gilhus
authors.forename: Johan Gorgas
authors.initials: JG
authors.lastname: Brun
authors.forename: Ansgar
authors.initials: A
authors.lastname: Espeland
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008022:Ligaments / Q000000981:diagnostic imaging / Q000473:pathology*; D016015:Logistic Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D019547:Neck Pain / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000473:pathology; D011859:Radiography; D012720:Severity of Illness Index; D013997:Time Factors; D055815:Young Adult