title: Heavily T2 weighted MR images of anterior optic pathways in patients with sellar and parasellar tumours - prediction of surgical anatomy.
abstract: OBJECTIVE
  Location of anterior optic pathways in sellar and parasellar tumours was preoperatively evaluated, by use of heavily T2 weighted MR images.
  
  
  METHODS
  Heavily T2 and conventional T1 weighted images were studied in 20 patients with sellar and parasellar tumours who underwent craniotomy. Pathology revealed pituitary adenoma in 5 patients, craniopharyngioma in 8 and parasellar meningioma in 7. Maximum sizes ranged from 15 mm to 58 mm. Sequence parameters of TR/TE for heavily T2 weighted and T1 weighted images were 5800/220 msec and 600/20 msec, respectively, and slice thickness was 3 mm for both.
  
  
  RESULTS
  The anterior optic pathway was detected in 95% on heavily T2 weighted images and 50% on T1 weighted images. All preoperative heavily T2 weighted images were compatible with operative findings. The optic chiasms were most commonly supero-posterior in pituitary adenomas, anterior (prefixed) in craniopharyngiomas and posterior in meningiomas. The optic nerves were commonly located superior or lateral to the tumours. However, parasellar meningiomas, off the midline, revealed the optic nerves in various locations, depending on the tumour origin. In such tumours, heavily T2 weighted images provided surgical information on the width of the working space through prechiasmal and/or optico-carotid spaces in the pterional approach. Spatial relation of the tumours to the lamina terminalis, anterior commissure and anterior communicating artery complex was clearly shown in craniopharyngioma patients, who underwent the anterior interhemispheric approach.
  
  
  CONCLUSIONS
  Heavily T2 weighted MR images are useful in determining the location of optic pathways and surgical approach and in individual prediction of the anatomy for even large sellar and parasellar tumours.
authors.affiliation: Department of Neurosurgery, Chiba University, School of Medicine, Chiba City, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Saeki
authors.forename: H
authors.initials: H
authors.lastname: Murai
authors.forename: M
authors.initials: M
authors.lastname: Kubota
authors.forename: N
authors.initials: N
authors.lastname: Fujimoto
authors.forename: T
authors.initials: T
authors.lastname: Iuchi
authors.forename: A
authors.initials: A
authors.lastname: Yamaura
authors.forename: K
authors.initials: K
authors.lastname: Sunami
mesh_terms: D000236:Adenoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D003397:Craniopharyngioma / Q000473:pathology* / Q000601:surgery; D003399:Craniotomy; D005260:Female; D005544:Forecasting; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000473:pathology* / Q000601:surgery; D008579:Meningioma / Q000473:pathology* / Q000601:surgery; D008875:Middle Aged; D009897:Optic Chiasm / Q000033:anatomy & histology*; D009900:Optic Nerve / Q000033:anatomy & histology*; D010347:Patient Care Planning; D010911:Pituitary Neoplasms / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D011300:Preoperative Care