title: Phased-array surface coil MR of the orbits and optic nerves.
abstract: OBJECTIVE
  To devise a practical technique for high-resolution evaluation of the anterior optic apparatus using a phased-array surface coil system, and to evaluate this system in patients with suspected optic pathway abnormalities.
  
  
  METHODS
  A four-element phased-array coil pair was placed on each side of the head, and signal-to-noise measurements were obtained using a head phantom. Comparison between the phased-array coil, the quadrature coil, and a single-turn 12.7-cm (5-in) surface coil was done. T1 spin-echo and T2 fast spin-echo sequences were obtained in the oblique axial and oblique sagittal planes, to approximate the long axis of the optic nerves and the nonoblique coronal plane.
  
  
  RESULTS
  The phantom signal-to-noise measurements at simulated locations of the optic nerve head, optic canal, and optic chiasm revealed an improvement of at least 30% using the phased-array system. Of 24 imaged cases, 9 had trauma, 5 had suspected neoplasms, and 2 had optic neuritis. In 3 patients, an unexpected diagnosis of optic pathway contusion or infarction was made. The remaining 8 patients had various suspected visual pathway lesions.
  
  
  CONCLUSIONS
  Phased-array surface coils allow rapid, thin-section imaging of the entire anterior optic pathway, with improved signal-to-noise ratio. This may improve evaluation of optic pathway lesions over conventional techniques.
authors.affiliation: Department of Radiology and Diagnostic Imaging Sciences Center, University of Washington School of Medicine, Seattle 98195, USA.
authors.forename: J
authors.initials: J
authors.lastname: Breslau
authors.forename: R W
authors.initials: RW
authors.lastname: Dalley
authors.forename: J S
authors.initials: JS
authors.lastname: Tsuruda
authors.forename: C E
authors.initials: CE
authors.lastname: Hayes
authors.forename: K R
authors.initials: KR
authors.lastname: Maravilla
mesh_terms: D000293:Adolescent; D000328:Adult; D001930:Brain Injuries / Q000175:diagnosis*; D002648:Child; D003288:Contusions / Q000175:diagnosis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D008953:Models, Anatomic; D009103:Multiple Sclerosis / Q000175:diagnosis; D009408:Nerve Compression Syndromes / Q000175:diagnosis; D009900:Optic Nerve / Q000473:pathology*; D020221:Optic Nerve Injuries; D009902:Optic Neuritis / Q000175:diagnosis*; D009915:Orbit / Q000473:pathology*; D009917:Orbital Fractures / Q000175:diagnosis*; D009918:Orbital Neoplasms / Q000175:diagnosis*; D012507:Sarcoidosis / Q000175:diagnosis; D014795:Visual Pathways / Q000293:injuries / Q000473:pathology; D014948:Wounds, Gunshot / Q000175:diagnosis