title: Efficacy of magnetic resonance imaging at 3 T compared with 1.5 T in small pituitary tumors for stereotactic radiosurgery planning.
abstract: OBJECTIVE
  The objective of this study was to determine the value of high-field magnetic resonance imaging and to clarify the characteristics of each image among three-dimensional gradient echo (3D-GRE), two-dimensional spin echo (2D-SE) and inversion recovery (2D-IR) sequences used as contrast-enhanced T1-weighted images for stereotactic irradiation treatment planning of sellar lesions.
  
  
  METHODS
  Pulse sequences of 2D-SE and 3D-spoiled gradient recalled acquisition in the steady state (3D-SPGR) using GRE at 1.5 T and 2D-IR and 3D-fast SPGR (3D-FSPGR) at 3 T after injection of contrast material were acquired for 14 small pituitary tumors. As quantitative methods, signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNR) were evaluated using a region-of-interest analysis.
  
  
  RESULTS
  There was no significant difference in SNR between 1.5-T SPGR and 3-T FSPGR, while 3-T IR was superior to 1.5-T SE. The 2D-SE and -IR provided significantly better CNR than 3D-GRE between tumor and normal structures.
  
  
  CONCLUSIONS
  Three Tesla was found to be superior to 1.5 T in distinguishing tumors from the normal sellar structure. Optimal dose planning will utilize each advantage of imaging; 3D-GRE allows high-resolution acquisition and 2D-SE and -IR can offer better tissue contrast.
authors.affiliation: Department of Radiological Sciences, Nagoya University Graduate School of Medicine, 1-1-20 Daikominami, Higashiku, Nagoya, Aichi, 461-8673, Japan, hnakazawa@kaikou.or.jp.
authors.forename: Hisato
authors.initials: H
authors.lastname: Nakazawa
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shibamoto
authors.forename: Takahiko
authors.initials: T
authors.lastname: Tsugawa
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Mori
authors.forename: Masami
authors.initials: M
authors.lastname: Nishio
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Takami
authors.forename: Masataka
authors.initials: M
authors.lastname: Komori
authors.forename: Chisa
authors.initials: C
authors.lastname: Hashizume
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Kobayashi
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010347:Patient Care Planning; D010911:Pituitary Neoplasms / Q000473:pathology* / Q000601:surgery*; D016634:Radiosurgery; D012658:Sella Turcica