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
Tatsuya Nakamuraa,
Shinji Naganawaa,
Tokiko Koshikawab,
Hiroshi Fukatsua,
Yasuo Sakuraia,
Ikuo Aokic,
Ayako Ninomiyac and
Takeo Ishigakia
a Department of Radiology, Nagoya University School of Medicine, Japan
b Department of Radiology, Komaki City Hospital, Japan
c Medical System Company, Toshiba Corporation, Tokyo, Japan
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FIG 1. A–H, MR images of the phantom acquired with a conventional 3D FASE protocol (4000/4 [TR/number of shots], A) and seven fast recovery 3D FASE protocols (B–H): 1000/4 (B), 1500/2 (C), 2000/2 (D), 2500/2 (E), 3000/2 (F), 3000/1 (G), 4000/1 (H). Grids were aligned parallel to the phase-encoding direction, which has more blurring than the frequency direction. Note that protocols A, B, D, E, and F clearly depict the 0.75-mm grids separately. Only protocol A depicts the 0.5-mm grids separately.
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FIG 2. Relative C/N values between CSF and cerebellum in a given time in the volunteer study. The fast recovery (FR) 3D FASE protocols in two-shot mode with TRs of 2000, 2500, and 3000 ms show comparable C/N values in a given time. Among these TRs, a TR of 2000 ms allows the widest slab coverage in a given time. Thus, a TR of 2000 ms with two-shot mode was used in this study. Note that the C/N in a given time is higher in most of the fast recovery 3D FASE protocols than in the conventional protocol.
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FIG 3. A–H, MR images acquired in the volunteer by means of a conventional 3D FASE protocol (4000/4 [TR/number of shots], A) and seven fast recovery 3D FASE protocols (B-H): 1000/4 (B), 1500/2 (C), 2000/2 (D), 2500/2 (E), 3000/2 (F), 3000/1 (G), 4000/1 (H).
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FIG 4. A–C, MR images show a small superior vestibular nerve schwannoma (arrow). The mass is clearly depicted with both 3D FASE protocols.
A, Conventional 3D FASE image (4000/240/1 [TR/TE/NEX]). Imaging time, 12 minutes.
B, ZIP fast recovery 3D FASE image (2000/240/1). Imaging time, 90 seconds.
C, Contrast-enhanced 3D-SPGR image (23/10/1).
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FIG 5. A–C, MR images show a small intravestibular schwannoma (arrow). The mass is clearly depicted with both 3D FASE protocols.
A, Conventional 3D FASE image (4000/240/1). Imaging time, 12 minutes.
B, ZIP fast recovery 3D FASE image (2000/240/1). Imaging time, 90 seconds.
C, Contrast-enhanced 3D SPGR image (23/10/1).
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