title: Dynamic magnetic resonance imaging evaluation of craniovertebral junction abnormalities.
abstract: OBJECTIVE
  To evaluate the role of dynamic magnetic resonance imaging (MRI) in craniovertebral junction (CVJ) abnormalities.
  
  
  METHODS
  Twenty-five patients with suspected CVJ abnormalities underwent dynamic MRI of the CVJ, and in 20 of these patients, noncontrast computed tomography scan of the CVJ was done. The images were evaluated for atlantoaxial instability (AAI), spinal canal narrowing, cord compression, presence of altered cord signal intensity, and bony abnormalities in neutral, flexion, and extension.
  
  
  RESULTS
  Dynamic MRI detected 15 cases of AAI (10 fixed and 5 mobile AAI), 21 patients had varying degrees of spinal canal narrowing. Five patients showed increased narrowing on flexion/extension. Two patients demonstrated direct cord compression in flexion, whereas in neutral position, only dural compression was seen. One patient had cord compression on extension that was not seen in neutral or flexed position.
  
  
  CONCLUSIONS
  Dynamic MRI was able to detect cases of cord compression that were not seen in neutral position and was diagnostic in all cases of mobile AAI where mobility at this joint affects the treatment options. Dynamic MRI is extremely useful for evaluating craniovertebral junction abnormalities and, in particular, cord compression.
authors.affiliation: Department of Radiodiagnosis, Postgraduate Institute of Medical Education and Research, Chandigarh, India. vivek_gupta21@hotmail.com
authors.forename: Vivek
authors.initials: V
authors.lastname: Gupta
authors.forename: Niranjan
authors.initials: N
authors.lastname: Khandelwal
authors.forename: Suresh Narain
authors.initials: SN
authors.lastname: Mathuria
authors.forename: Paramjit
authors.initials: P
authors.lastname: Singh
authors.forename: Ashish
authors.initials: A
authors.lastname: Pathak
authors.forename: Sudha
authors.initials: S
authors.lastname: Suri
mesh_terms: D000328:Adult; D001268:Atlanto-Axial Joint / Q000473:pathology*; D002574:Cervical Vertebrae / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D013117:Spinal Cord Compression / Q000473:pathology*; D013130:Spinal Stenosis / Q000473:pathology*; D014057:Tomography, X-Ray Computed