Development of Desktop MR Microscopes

台式核磁共振显微镜的开发

• 批准号: 12555016
• 负责人: KOSE Katsumi
• 金额: $ 7.94万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12555016/
• 关键词: MRI; MR Microscope; permanent magnet; NMR; 勾配コイル; 静磁場

Compact MR microscopes were developed using yokeless permanent magnets. Two different size permanent magnets with 1.0 T central magnetic fields were used ; larger one : gap width ; 60 mm, weight ; 210 kg, size ; 36 cm x 32 cm x 28 cm, homogeneous regions ; 20 mm dsv (13 ppm), and smaller one : gap width ; 41 mm, weight ; 85 kg, size ; 27 cm x 24 cm x 18 cm, homogeneous regions ; 13 mm dsv (13 ppm). The most serious problem in the development of the MR microscopes was temperature drift of the central magnetic field mainly due to the large negative temperature coefficient (-1200 ppm/deg) of the residual magnetic flux density of the Nd-Fe-B magnetic material. Long-term changes of magnet temperatures and Larmor precession frequencies were measured under various thermal conditions of the magnets. As a result, we concluded that the internal NMR locking technique in a time-sharing mode of which time interval was several minutes could compensate the frequency drift and present high-resolution 3D images of chemically fixed animal samples with less than 100 microns cube voxel dimensions.

使用无轭永磁体开发了紧凑型MR显微镜。使用具有1.0 T中心磁场的两个不同尺寸的永磁体;较大的一个：间隙宽度; 60 mm，重量; 210 kg，尺寸; 36 cm x 32 cm x 28 cm，均匀区域; 20 mm dsv（13 ppm），较小的一个：间隙宽度; 41 mm，重量; 85 kg，尺寸; 27 cm x 24 cm x 18 cm，均匀区域; 13 mm dsv（13 ppm）。在MR显微镜的发展中最严重的问题是中心磁场的温度漂移，主要是由于Nd-Fe-B磁性材料的剩余磁通密度的大的负温度系数（~ 1200 ppm/deg）。在不同的热条件下，测量了磁体温度和拉莫尔进动频率的长期变化。因此，我们的结论是，内部NMR锁定技术的时间间隔为几分钟的分时模式，可以补偿频率漂移，并提出高分辨率的三维图像的化学固定的动物样品与小于100微米的立方体体素尺寸。

项目成果

Nobuaki Ishida, Hiroyuki Takano, Shigehiro Naito, Seiichiro Isobe, Kunihiko Uemura, Tomoyuki Haishi, Katsumi Kose, Mika Koizumi, Hiromi Kano: "Architecture of baked breads depicted by a magnetic resonance imaging"Magnetic Resonance Imaging. 19. 867-874 (2

Nobuaki Ishida、Hiroyuki Takano、Shigehiro Naito、Seiichiro Isobe、Kunihiko Uemura、Tomoyuki Haishi、Katsumi Kose、Mika Koizumi、Hiromi Kano：“磁共振成像描绘的烤面包结构”磁共振成像。

Tomoyuki Haishi, Takaaki Uematsu, Yoshimasa Matsuda, Katsumi Kose: "Development of a 1.0 T MR microscope using a Nd-Fe-B permanent magnet"Magnetic Resonance Imaging. 19. 875-880 (2001)

Tomoyuki Haishi、Takaaki Uematsu、Yoshimasa Matsuda、Katsumi Kose：“使用 Nd-Fe-B 永磁体开发 1.0 T MR 显微镜”磁共振成像。

N.Ishida et al.: "Architecture of baked bread depicted by a magnetic resonance imaging"Magnetic Resonance Imaging. 19. 867-874 (2001)

N.Ishida 等人：“磁共振成像描绘的烤面包的结构”磁共振成像。

T.Haishi et al.: "Development of a 1.0T MR microscope using a Nd-Fe-B permanent magnet"Magnetic Resonance Imaging. 19. 875-880 (2001)

T.Haishi 等人：“使用 Nd-Fe-B 永磁体开发 1.0T MR 显微镜”磁共振成像。

H.Yoshioka: "MR microscopy of articular carilage at 1.5T"Skeltal Radiology. 31. 505-510 (2002)

H.Yoshioka：“1.5T 下关节软骨的 MR 显微镜检查”骨骼放射学。