title: Value of "functional" magnetic resonance imaging in the diagnosis of ligamentous affection at the craniovertebral junction.
abstract: BACKGROUND
  Objective of this investigation was to evaluate the rotational mobility at the craniocervical junction and changes in the width of the subarachnoid space during head rotation in healthy volunteers using Magnetic Resonance Imaging (MRI).
  
  
  METHODS
  In 30 healthy volunteers axial 3mm Half-Fourier Acquisition Single-Shot Turbo Spin-Echo (HASTE) sequences were obtained with the subject's head in neutral position, and in maximal rotation to the left and right respectively. All MRI examinations were evaluated by two neuroradiologists in consensus. The ranges of axial rotation at C0-C2 as well as the width of the subarachnoid space in neutral, and in maximal rotated position were measured. Student's t-tests were used to compare group differences.
  
  
  RESULTS
  Total range of right-to-left-rotation at C0-C2 was 59-183° with mean rotation to the right and left side of 70° (±12.7°) and 75° (±13.0°). Difference between degrees of rotation to both sides was on average 4.9° (±7.1°) with a significantly greater rotational range to the left compared to the right. In neutral position, distance between the dura and the ventral wall of the cervical spinal cord was 1.6-4.2mm. In active rotation interface between dura and myelon was evident in 19 volunteers with unilateral contact in 7, and bilateral contact in 12 cases.
  
  
  CONCLUSIONS
  High variablity of rotational mobility at the craniocervical junction and attenuation of width of the subarachnoid space during head rotation are frequent findings in an asymptomatic population. Our results indicate that the assessment of these parameters is of limited diagnostic value in patients with whiplash-associated disorders.
authors: Department of Neuroradiology, University of Munich (LMU), Marchioninistrasse 15, D - 81377 Munich, Germany. nina.lummel@med.uni-muenchen.de
authors: Nina
authors: N
authors: Lummel
authors: Harro
authors: H
authors: Bitterling
authors: Andrea
authors: A
authors: Kloetzer
authors: Christian
authors: C
authors: Zeif
authors: Hartmut
authors: H
authors: Brückmann
authors: Jennifer
authors: J
authors: Linn
mesh_terms: D000328:Adult; D001269:Atlanto-Occipital Joint / Q000033:anatomy & histology* / Q000502:physiology*; D005260:Female; D006801:Humans; D008022:Ligaments / Q000033:anatomy & histology* / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult