title: Imaging features in Hirayama disease.
abstract: OBJECTIVE
  To evaluate the MR findings in clinically suspected cases of Hirayama disease.
  
  
  METHODS
  The pre and post contrast neutral and flexion position cervical MR images of eight patients of clinically suspected Hirayama disease were evaluated for the following findings: localized lower cervical cord atrophy, asymmetric cord flattening, abnormal cervical curvature, loss of attachment between the posterior dural sac and subjacent lamina, anterior shifting of the posterior wall of the cervical dural canal and enhancing epidural component with flow voids. The distribution of the above features in our patient population was noted and correlated with their clinical presentation and electromyography findings.
  
  
  METHODS
  Although lower cervical cord atrophy was noted in all eight cases of suspected Hirayama disease, the rest of the findings were variably distributed with asymmetric cord flattening, abnormal cervical curvature, anterior shifting of the posterior wall of the cervical dural canal and enhancing epidural component seen in six out of eight (75%) cases. An additional finding of thoracic extension of the enhancing epidural component was also noted in five out of eight cases.
  
  
  CONCLUSIONS
  Dynamic post contrast MRI evaluation of cervicothoracic spine is an accurate method for the diagnosis of Hirayama disease.
authors.affiliation: Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India.
authors.forename: Hemant A
authors.initials: HA
authors.lastname: Sonwalkar
authors.forename: Rakesh S
authors.initials: RS
authors.lastname: Shah
authors.forename: Firosh K
authors.initials: FK
authors.lastname: Khan
authors.forename: Arun K
authors.initials: AK
authors.lastname: Gupta
authors.forename: Narendra K
authors.initials: NK
authors.lastname: Bodhey
authors.forename: Surjith
authors.initials: S
authors.lastname: Vottath
authors.forename: Sukalyan
authors.initials: S
authors.lastname: Purkayastha
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000293:Adolescent; D002574:Cervical Vertebrae / Q000473:pathology; D002648:Child; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009431:Neural Conduction / Q000502:physiology; D010525:Peripheral Nerves / Q000503:physiopathology; D014897:Spinal Muscular Atrophies of Childhood / Q000175:diagnosis* / Q000503:physiopathology*; D034941:Upper Extremity / Q000503:physiopathology*; D055815:Young Adult