title: Imaging characteristics of cervical spine extra-arachnoid fluid collections managed conservatively.
abstract: OBJECTIVE
  Determine the MRI characteristics of large post-traumatic cervical spine extra-arachnoid collections managed conservatively in clinically stable patients and whether evidence of clinical or imaging deterioration materialized.
  
  
  METHODS
  Following IRB approval, we conducted a retrospective search for all patients (>16 years old) over a 17-months period who had an extra-arachnoid fluid collection reported on a post-traumatic cervical spine MRI. Patients were excluded if they had surgery for an unstable fracture (n = 21), emergent decompression (n = 1) or lacked a follow-up MRI within 15 days (n = 1). Two MSK radiologists recorded the size, morphology and MRI signal characteristics of the collections.
  
  
  RESULTS
  Eight patients (5 male, 3 female) met the inclusion criteria (mean age 40 years; range 19-78 years). Seven of the eight patients had fluid collections that demonstrated thin, tapered margins, extended >7 vertebral bodies and involved >180 degrees of the spinal canal. The signal characteristics of these collections varied: hyper-T1/iso-T2 (n = 1), iso-T1/T2 (n = 3), hyper-T1/hypo-T2 (n = 3) and mixed-T1/T2 (n = 1). Six of seven collections were ventral. Follow-up MRI demonstrated resolution/significant decrease in size (n = 4 between 1 and 12 days) or no change/slight decrease in size (n = 3; between 2 and 11 days). None of the seven fluid collections enlarged, no patient had abnormal cord signal, and no patient's neurologic symptoms worsened. One of eight patients had a dorsal "mass-like" collection that was slightly smaller 9 days later.
  
  
  CONCLUSIONS
  In stable patients with large, tapered post-traumatic cervical spine extra-arachnoid collections managed non-surgically, none developed (1) clinical worsening, (2) abnormal cord signal or (3) collection enlargement, regardless of the collection's signal characteristics.
authors.affiliation: Department of Radiology and Medical Imaging, University of Virginia, 1218 Lee Street, Box 800170, Charlottesville, VA, 22908, USA.|Progressive Radiology, 7799 Leesburg Pike, Suite 1000 N, Falls Church, VA, 22043, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Lawrence
authors.affiliation: Department of Radiology and Medical Imaging, University of Virginia, 1218 Lee Street, Box 800170, Charlottesville, VA, 22908, USA.|Carolina Radiology Associates, LLC, P.O. Box 1885, Myrtle Beach, SC, 29578, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Trotta
authors.affiliation: Department of Orthopedic Surgery, University of Virginia, P.O. Box 800159, Charlottesville, VA, 22901, USA.
authors.forename: Francis H
authors.initials: FH
authors.lastname: Shen
authors.affiliation: Department of Radiology and Medical Imaging, University of Virginia, 1218 Lee Street, Box 800170, Charlottesville, VA, 22908, USA.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Druzgal
authors.affiliation: Department of Radiology and Medical Imaging, University of Virginia, 1218 Lee Street, Box 800170, Charlottesville, VA, 22908, USA. mf3kx@virginia.edu.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Fox
mesh_terms: D000328:Adult; D000368:Aged; D001099:Arachnoid / Q000000981:diagnostic imaging*; D002574:Cervical Vertebrae; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009333:Neck / Q000000981:diagnostic imaging; D012189:Retrospective Studies; D013124:Spinal Injuries / Q000000981:diagnostic imaging*; D013131:Spine / Q000000981:diagnostic imaging*; D055815:Young Adult
keywords: Cervical spine; Epidural hematoma; Magnetic resonance imaging; Trauma