TY - JOUR T1 - High-Resolution MR Cisternography of the Cerebellopontine Angle, Obtained with a Three-Dimensional Fast Asymmetric Spin-Echo Sequencein a 0.35-T Open MR Imaging Unit JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 1143 LP - 1147 VL - 20 IS - 6 AU - Shinji Naganawa AU - Tokiko Ito AU - Eriko Iwayama AU - Hiroshi Fukatsu AU - Takeo Ishigaki Y1 - 1999/06/01 UR - http://www.ajnr.org/content/20/6/1143.abstract N2 - Summary: High-resolution MR cisternography performed with 3D fast asymmetric spin-echo imaging (3D fast spin-echo with an ultra-long echo train length and asymmetric Fourier imaging) was optimized in a 0.35-T open MR imaging unit. The 0.35- and 1.5-T images of the two volunteers and three patients with acoustic schwannomas were then compared. The optimal parameters for images obtained by 3D fast asymmetric spin-echo imaging at 0.35 T were as follows: field of view, 15 cm; matrix, 256 × 256 × 40; section thickness, 1 mm; echo train length, 76; and imaging time, 10 minutes 44 seconds. Scans obtained from both normal volunteers showed the facial, cochlear, and superior and inferior vestibular nerves separately in the internal auditory canal on both 0.35- and 1.5-T images. All three acoustic schwannomas were depicted on both 0.35- and 1.5-T images. Screening for disease at the cerebellopontine angle and in the internal auditory canal, without the administration of contrast material on a low-field open MR imaging unit and within a clinically acceptable imaging time, may be possible. Further controlled prospective studies are required, however, before implementation on a wide basis. If proved effective, this may be of particular value for reducing healthcare costs and for imaging claustrophobic and pediatric patients in an open system. ER -