title: High-spatial-resolution MR cisternography of the cerebellopontine angle in 90 seconds with a zero-fill interpolated fast recovery 3D fast asymmetric spin-echo sequence.
abstract: OBJECTIVE
  Although the 12-minute 3D fast asymmetric spin-echo (FASE) protocol for imaging the inner ear has been satisfactory, reducing imaging time to minimize patient discomfort and maximize system throughput is desirable. We therefore evaluated the performance of a zero-fill interpolated (ZIP) fast recovery 3D FASE sequence in screening for cerebellopontine (CP) angle lesions in 90 seconds.
  
  
  METHODS
  Thirty consecutive patients known or suspected to have CP angle lesions underwent MR imaging at 1.5 T with use of bilateral quadrature phased-array coils designed for examination of the CP angle. Conventional 3D FASE images (4000/240/1 [TR/TE/NEX]) were obtained in 11 minutes 48 seconds with a field of view (FOV) of 16 cm, matrix of 512 x 512 x 40, section thickness of 0.8 mm, and echo train length of 80. Then, ZIP fast recovery 3D FASE images (2000/240/1) were obtained in 90 seconds by using the same FOV. Contrast-enhanced T1-weighted 3D spoiled gradient-echo (SPGR) images were obtained as the reference standard. Three radiologists evaluated the images independently. Conventional 3D FASE and ZIP fast recovery 3D FASE images were reviewed at separate sessions.
  
  
  RESULTS
  On 3D SPGR images, 10 tumors were detected in 10 of the 30 patients. All lesions were depicted with both 3D FASE protocols. There were no false-positive results with either 3D FASE protocol. Both protocols showed 100% sensitivity and 100% specificity for all three reviewers.
  
  
  CONCLUSIONS
  High-spatial-resolution MR cisternography with the ZIP fast recovery 3D FASE protocol in 90 seconds results in a substantial reduction (by a factor of about eight) in the time required for screening for CP angle lesions compared with the previously reported conventional 3D FASE protocol, while maintaining high sensitivity and specificity.
authors.affiliation: Department of Radiology, Nagoya University School of Medicine, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nakamura
authors.forename: Shinji
authors.initials: S
authors.lastname: Naganawa
authors.forename: Tokiko
authors.initials: T
authors.lastname: Koshikawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Fukatsu
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Sakurai
authors.forename: Ikuo
authors.initials: I
authors.lastname: Aoki
authors.forename: Ayako
authors.initials: A
authors.lastname: Ninomiya
authors.forename: Takeo
authors.initials: T
authors.lastname: Ishigaki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002528:Cerebellar Neoplasms / Q000175:diagnosis*; D002530:Cerebellopontine Angle / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis*; D019047:Phantoms, Imaging