MRI 低温探头

用于小鼠的MRI低温探头

高灵敏度的MRI 低温探头

与标准的室温射频线圈相比，布鲁克MRI CryoProbe 将活体检测灵敏度提高了 2.5 至 5.3 倍

布鲁克提供了适用于 BioSpec® 和 PharmaScan® 产品线的 MRI CryoProbe™。它采用 MRI 低温冷头技术和 MRI 冷冻剂处理方法，能够保持非常低的温度，并采用闭环循环冷却射频线圈和前置放大器，在常规 MRI 应用中，该产品相比于标准的室温射频线圈的将活体灵敏度提高了 2.5 至 5.3 倍。此外，它在小动物 MRI 中树立了新的信噪比标杆。

主要特点

体内灵敏度提高 2.5 至 5.3 倍
更高的空间分辨率和更短的扫描时间
设计灵活，易于安置
通过监控和保温措施，避免冷表面与动物接触
在磁体外冷却
满足所有关于用户和动物的安全要求

技术细节

MRI 低温探头技术

布鲁克MRI低温探头系统将射频线圈和前置放大器用闭路循环制冷系统来冷却。由于射频线圈和相关电子元件的热噪音与样本噪音相当，因此大大降低这种噪音能够显著提高MRI信噪比。布鲁克 BioSpin 是用于高分辨率 NMR 的 CryoProbe 技术发展的先驱，在过去 14 年间，世界各地的客户安装了 1300 多套 CryoProbe。

MRI CryoProbe 相比于标准的室温射频线圈提供了极大的 SNR 提升：

体内分辨率高达 20 µm
更短的测量时间
室温线圈不适用的新应用（高分辨率、fMRI…）
更短的麻醉时间
由于测量时间更短，因此研究变得更加经济有效

简便易用的 CryoProbe 设置

MRI CryoProbes 的动物处理和监护非常类似于标准的室温射频线圈。CryoProbe 冷却可在磁体外部实现，确保扫描仪时间得到最佳使用。

MRI CryoProbe 系列：4 种，涵盖所有应用

1. 质子正交发射接收一体 MRI CryoProbe，用于 105 mm 梯度或更大梯度

Bruker 在 BioSpec®、 PharmaScan® 和 ClinScan® 产品线中提供了该 MRI CryoProbe™。在常规 MRI 活体应用中，该产品相比于标准的室温射频线圈的灵敏度提高了 2.5 倍以上。可提供从 3 T 至 15.2 T 各种磁场强度的质子正交发射接收一体CryoProbe。

2. 用于 6 cm 梯度的质子正交发射接收一体 MRI CryoProbe

该 MRI CryoProbe 专门针对具有 6 cm 梯度线圈的布鲁克小鼠扫描仪开发，也可用于配备 6 cm 梯度线圈的BioSpec系统。用于 BGA6S 梯度的该质子正交发射接收一体 MRI CryoProbe 是 7 T 至 15.2 T 的标准产品。

3. 用于 12 cm 梯度及更大梯度的质子四通道相阵控

由于其产生巨大的信号增益，因此能够在保持分辨率的同时大大缩短扫描时间。相比于室温 4 通道相阵控线圈，通常可获得 2.6 倍的信噪比增益。当前，这些 CryoProbes 在 7 T 和 9.4 T 系统中作为标准产品提供。其它场强正在开发中。

4. 组合的质子室温射频线圈的 X 核 MRI CryoProbe

该信噪比增益得益于较低的核磁共振频率：核的共振频率越低，则 SNR 增益越高。因此，在13C 测量中能够实现 5 倍的信噪比增益。可根据要求提供其它 X 核 CryoProbe。

应用

活体小鼠脑解剖学

Very high spatial resolution: In-plane (19.5 µm)², slice thickness: 150 µm, while maintaining good contrast and signal-to-noise ratio. (a) Full field of view FLASH image, (b) Expanded area (c) Phase image of the same FLASH image

利用FLASH进行活体小鼠脑解剖 "MR组织学"

(a,d) Expanded FLASH images, (b,e) phase images of the very same FLASH images, and (c,f) corresponding Nissl stained plates. Images (a-c) Bregma -2.7, (d-f) Bregma -1.9. MRI acquisition details: Resolution in-plane: (19.5 x 19.5) µm², field of view: (1.5

小脑、海马和尾状丘脑的细节非常出色。

Six full field of view coronal RARE slices of mouse brain in vivo. Acquisition details: RARE, 6 echoes, resolution: (29 x 29 x 200) µm³, TR: 3500 ms, TE: 25.3 ms, scan time: 25 min 40 s. Picture made at 15.2T field strength

"MR Histology" Using RARE

Direct comparison of high-resolution in vivo mouse brain images with Nissl stained plates. Resolution in-plane: (29 µm)², Slice thickness: 200 µm. (a) Full field of view coronal RARE image. Picture made at 15.2T field strength

"MR Histology" Using RARE

Direct comparison of high-resolution in vivo mouse brain images with Nissl stained plates. Resolution in-plane: (29 µm)², Slice thickness: 200 µm. Image (b) shows an expanded view of the hippocampal area, and image (c) a corresponding Nissl stained plate

3D Time of Flight (ToF) Angiography in vivo

3D Time of Flight (ToF) angiography in vivo without contrast agent, (a) MIP rotating around AP axis. Acquisition details: GEFC, TR: 37 ms, TE: 3.3 ms, matrix: 384 × 256 × 256, resolution: (49 µm)³ isotropic. Picture made at 15.2T field strength

3D Time of Flight (ToF) Angiography in vivo

3D Time of Flight (ToF) Angiography in vivo without contrast agent, (b) MIP rotating around LR axis. Acquisition details: GEFC, TR: 37 ms, TE: 3.3 ms, matrix: 384 × 256 × 256, resolution: (49 µm)³ isotropic. Picture made at 15.2T field strength

In vivo murine brain micro-imaging with resolutions slowly approaching cellular levels

In vivo murine brain micro-imaging with resolutions slowly approaching cellular levels becomes feasible at high magnetic field strengths (15.2 T) using a cryogenic RF coil.

2D Gradient echo

2D Gradient echo, TE/TR= 5.5/400 ms, α = 30°, 40x40x160 µm, 21 min Courtesy Aline Seuwen, ETH Zurich

3D FLASH

3D Flash: 40*40*60 μm, TR=400, TE=7.6, α= 30°, 1h17min Courtesy Aline Seuwen, ETH Zurich

High resolution structural imaging

Upper row: 2D Gradient echo, TE/TR= 5.5/400 ms, α = 30°, 40x40x160 µm, 21 min. Lower row: 2D spin echo,TEeff/TR= 45/3500 ms, 42x44x300 µm, 21 min, Courtesy Aline Seuwen, ETH Zurich

FLASH

FOV: 1.6*1.6 cm, Mtx: 384*384, Res: 42*42 um, Slice th.: 150 um, TE: 5.5 ms, TR: 400 ms, Acqu. Time: 25 min

TURBORARE T2

FOV: 1.96*2.54 cm, Mtx: 512*512, Res: 38*50 um, Slice th.: 300 um, TE (eff): 46.3 ms, TR: 3500 ms, Acqu. Time: 1h

Cardiac Angiography of Mouse

The full cycle of a beating mouse heart in MIP representation. IntraGate self-gated angiography (work-in-progress)

Mouse Spine Angiography with Self-Gating

Maximum Intensity Projection of mouse spine with MRI CryoProbe. Visualization of posterior intercostal arteries and veins.

DTI of Mouse Spine

Gray-white matter differentiation in fractional anisotropy map. Clear identification of nerve fibers (yellow arrows) in the color-coded diffusion tensor display.

Mouse Spine Imaging

High resolution T2- weighted TurboRARE mouse spine images. Excellent differentiation of gray and white matter.

Liver Angiography of Mouse

Triggered Snapshot Time-of-Flight angiography. Visualization of liver vessels with Maximum Intensity Projection

SWI of Subcutaneous Mouse Flank Tumors

SWI processed FLASH image of a subcutaneous mouse tumor, and the corresponding RARE reference image

ISIS Localized 13C Spectroscopy of Mouse Brain

Direct detection of glucose metabolism in mouse brain. After overnight fasting, a bolus of 130 mg/kg [1-13C] glucose was given within 20 sec, f4

STEAM: Short TE Localized 1H Spectroscopy of Mice

STEAM localized 1H spectroscopy in mouse frontal brain. Minimal evolution of VTJ-coupled resonances due to short echo time (3 ms); Optimal for investigation of macromolecules

Tumor Partitioning: Susceptibility Weighted Imaging

Subcutaneous tumors in mice; Correlation of susceptibility weighted imaging and T2* maps. SWI indicated tumor vascularization. Precise partitioning of the tumor

Susceptibility Weighted Imaging of Mouse Brain