这项工作是在病童医院和多伦多大学的鼠标成像中心（MICE）的一部分。

1。多鼠体内的脑功能成像: 环境控制和成像活的动物，几个主要特点时，必须在整个成像会议:1），2麻醉的安全方法）3）生理监测。此外，成像时多个主体同时，有增加的复杂性有关准备和重现性动物的立场，以方便图像配准的易用性和速度。因此，三种主要的自定义组件的设计和制造:加载系统插入到小鼠内MRI射频线圈，感应室，以方便准备和与嵌入式监控平台，导致规范的地位。 加载系统: 鼠标加载系统由两个主要部分:"鼠标配置单元"和"装阵"。鼠标配置单元的主要功能是7千足虫射频线圈（瓦里安核磁共振系统，帕洛阿尔托，加利福尼亚）在磁铁内六角阵列孔的位置。装阵的目的是持有和运输多个小鼠在50毫升的离心管内孔钻通过他们的技巧，让麻醉气体进入。后小鼠麻醉，在磁铁附近准备区域的监控设备的接口，它们是插入修改后的离心管，并安装到加载阵列。安装后所有小鼠，运输和装阵插入磁体和定位，在铁路系统。铁路系统允许情侣用鼠标配置单元的阵列，当推磁铁的孔。当完全插入磁铁，到麻醉输送系统的射频线圈内的离心管码头。与氧气混合的异氟醚是提供鼠标蜂房结束的标本，通过每一个人的线圈沿轴管。这种麻醉气体混合物流入管，过去的小鼠和清除附着回装阵（图1）由一个活跃的单位收集。 感应商会: 由于成像时间可以长达三个小时，最大限度地减少动物的准备时间是至关重要的限制鼠标的接触麻醉。因此，我们开发了一个定制的感应室精简编制过程（图2）。定制的感应室创建一个单一的环境诱导和处理多个小鼠。从丙烯酸构造，感应室selfclosing硅虹膜端口的功能，以尽量减少麻醉剂泄漏，并允许用户访问的内部环境，而不需要特殊的手套。相比传统的面具和一个鼠标的电路，感应室是大到足以容纳到二十只小鼠，并允许自由操纵​​的老鼠没有繁琐管和口罩的附件。单位提供的麻醉气体的流量恒定，这是使用被动清除系统收集。电阻加热元件用于加热室的地板，在制备过程中保持动物的体温。 雪橇: 准备的MRI小鼠的最尴尬和耗时的方面之一是心电图（ECG）电极和直肠温度探头的应用程序。此外，许多传统的电极，如袖口和电极针，发现扭曲动物的姿势，使其难以规范定位。因此，我们设计了一个自定义窗体定位平台装有嵌入式心电图，呼吸和温度探测器称为"雪橇"（美国专利7146936）（图3）。魔术贴紧固件的议案限制被用来限制头部运动。 多鼠体内的脑成像步骤: <ol><li>所有鼠标的研究需要当地ACC（动物保健委员会），IACUC（机构动物护理和使用委员会）或相当于鼠​​标处理程序批准。 </li><li>应在生物安全柜（BSC）和MRI检查组的所有程序，如动物识别和称重。动物们转移到一个高温高压灭菌的塑料容器中，运到磁共振成像感应室。 </li><li>小鼠麻醉在预热感应室使用4％的异氟醚和4升/分钟的氧气。动物完全麻醉，一旦他们无法应对爪子掐。使用头发卸妆（NAIR）如有必要，以提供更好的接触与心电图和温度监测设备已内置入一个自定义的雪橇从胸前的毛皮被删除。夏娃的药膏（泪Naturale PM）是适用于眼睛，以防止干燥，约0.3毫升生理盐水皮下注射，保持水化。 </li><li>的Gd - DTPA - BMA（OmniScan的）可能如果需要对比增强。如果要使用的Gd - DTPA，将生理盐水（终体积300uL稀释）和单剂量在1毫摩尔/公斤的前议员会议通过IP管理。 </li><li>小鼠，然后装入个人雪橇，固定头带和幻灯片到不限成员名额50ml的锥形管（图3）。可以一次扫描多达7个活体小鼠。一旦所有的动物都装有生理连接监测，设置在磁铁的异氟醚水平孔，2％，氧气含量为8 L / min的。 </li><li>锥形管安装到每个射频线圈在磁铁的中心定位孔均匀设计位置小鼠成一个系统的对接（图1）。一旦加载，异氟醚可降低到0.9-2％。整个扫描过程中对每个动物心电图和温度进行监测。在扫描与热空气的过程中，动物保持温暖。 </li><li>每个三维扫描时间约为3小时。详情如下:2300毫秒和36毫秒TEeff TR快速自旋回波。回声列车1平均长度为8。由此产生的图像分辨率是125微米（图4）。 </li><li>当扫描完成后，动物是从磁铁中删除和卸载在一个充满温暖的感应与100％氧气室。动物们转移到一个塑料的密封容器和一个BSC下运输。它们被放置在一个温暖的免费笼草案，并允许从麻醉中恢复。 </li></ol> 2。多鼠体内的脑功能成像: 固定磁共振成像运动伪影的影响，实现更高的分辨率比实时成像。高分辨率，三维数据集提供极大的灵活性，在提取定量信息，并允许自动图像分析。 16高分辨率MR固定在颅骨的老鼠的大脑在一夜之间扫描会话的数据集的并行采集自定义的射频线圈阵列。 16线圈离体脑成像阵列: 图像16样品同时创建一个定制的16线圈电磁阵列。这种设计改善后，同时在60毫米插入梯度设置用于图像的三个样本的早期原型。 8圈电磁线圈，两端在伤口内提供10％的统一灵敏度超过了26毫米长度和模块化车厢"（Idziak和Haeberlen，1982年）内单独屏蔽。 16线圈车厢组装一帧（图5），仓内的梯度线圈和夹具，使用气动膀胱，以尽量减少运动。 多鼠体内的脑成像步骤: <ol><li>打开胸腔，并插入进针麻醉小鼠的心脏的左心室（或安全翼输液器，25G X 3 / 4）（通过腹腔注射氯胺酮（150毫克/公斤）和甲苯噻嗪（10毫克/公斤） 。切右耳廓。 </li><li> Transcardiac灌注冲洗，用30 mL室温1 X PBS + 1μg/ ml肝素（1000美国药典单位/ ml）+ 2个MM在大约100毫升/小时的流量ProHance。 </li><li>用30 mL 4％PFA固定通（室温）+ 2 100毫米ProHance毫升/小时。 </li><li>斩首和清除皮肤，下颌，耳朵，鼻尖软骨。 </li><li>广场余下的头骨结构在4％煤灰+ 2毫米ProHance一夜之间在4 ° C。 </li><li>转移到1X PBS + 0.02％的叠氮化钠+ 2毫米ProHance。 </li><li>高分辨率三维7特斯拉的核磁共振扫描之间发生4天，不长于2.5个月后灌注。大脑是放置在一个16通道的电磁线圈阵列（图5）。 </li><li>成像参数如下:快速自旋回波与TR 325毫秒和30毫秒，回声6列车4平均长度TEeff。最终图像有一个各向同性分辨率为32微米（图6），扫描时间约12小时。 </li><li>扫描后，将10％的福尔马林头骨+ 2毫米保存ProHance。 </li></ol> 3。代表性的成果: <img src="/files/ftp_upload/2497/2497fig1.jpg" alt="图1" /> 图1，鼠标装载系统。 "装阵"和"鼠标蜂房"与常见的玻璃纤维的铁路系统连接。 <img src="/files/ftp_upload/2497/2497fig2.jpg" alt="图2" /> 图2感应室。 <img src="/files/ftp_upload/2497/2497fig3.jpg" alt="图3" /> 图3 A）的雪橇，显示嵌入式监测传感器和头枕。 B）与麻醉鼠标头枕上雪橇附后。雪橇大会很容易滑入离心管。 <img src="/files/ftp_upload/2497/2497fig4.jpg" alt="图4" /> 图4。 </strong&gt; 在体内多发性脑图像的代表，从一个3小时的三维扫描。 <img src="/files/ftp_upload/2497/2497fig5.jpg" alt="图5" /> 图5:16通道扫描16个固定的大脑标本的电磁线圈阵列。 <img src="/files/ftp_upload/2497/2497fig6.jpg" alt="图6" /> 图6代表前体内的脑图像。

<ol>
	<li>Bock, N. A., Konyer, N. B., Henkelman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple-mouse+MRI.">Multiple-mouse MRI.</a> Magn. Reson. Med. 49, 158-167 (2003).</li><li>Dazai, J., Bock, N. A., Nieman, B. J., Davidson, L. M., Henkelman, R. M., Chen, X. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+mouse+biological+loading+and+monitoring+system+for+MRI.">Multiple mouse biological loading and monitoring system for MRI.</a> Magn. Reson. Med. 52, 709-715 (2004).</li><li>Spring, S., Lerch, J. P., Henkelman, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sexual+dimorphism+revealed+in+the+structure+of+the+mouse+brain+using+three-dimensional+magnetic+resonance+imaging.">Sexual dimorphism revealed in the structure of the mouse brain using three-dimensional magnetic resonance imaging.</a> NeuroImage. 35, 1424-1433 (2007).</li><li>Idziak, S., Haeberlen, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+and+construction+of+a+high+homogeneity+rf+coil+for+solid-state+multiple-pulse+NMR.">Design and construction of a high homogeneity rf coil for solid-state multiple-pulse NMR.</a> J. Magn. Reson. 50, 281-288 (1982).</li></ol>

都在体内和体外鼠标成像系统图像的多个一次科目增加，恕不成像研究的吞吐量大大提高了成像时间。 在体内和体外多鼠标成像技术的脑图像质量高，适合表型分别在小鼠大脑中的主要和次要结构。 为了尽量减少动物多个标本的准备时间，并行化的进程是非常重要的。例如，允许同时多个标本感应感应室的发展，并雪橇同步心电图和温度探测器的应用，而规范的身体定位。此外，我们的前活体成像系统，使我们能够获得高分辨率的16个固定的整个大脑的三维图像，在同一时间，这是适合于高通量分型研究。 在活体成像系统包括可能限制我们无法单独控制每个鼠标的麻醉剂和温度。如果需要个别麻醉控制，可以实现与每个鼠标专用麻醉喷雾器此外。 活体成像系统中的另一个限制是，扫描限制小于约32克的老鼠。然而，目前的计划，增加线圈的大小，以容纳较大的动物。

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<td>Isoflurane, USP (AErrane)</td>
<td>&nbsp;</td>
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<td>CA2L9108</td>
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multiple-mouse neuroanatomical magnetic resonance imaging

鼠标与磁共振成像（MRI）的表型领域正在迅速增长，出于表征和评价人类疾病的小鼠模型需要改进的工具。 MRI是一个出色的方式调查基因改变的动物。它能够覆盖全脑，可在体内 ，并提供了多个调查neuranatomy和生理学的不同方面的对比机制。高场强扫描仪能够扫描多个小鼠的出现，同时，允许新的突变快速表型。 有效鼠标MRI研究的实验设计的许多方面需要注意。在这篇文章中，我们将描述一般的方法来获取鼠标使用系统表型高质量的图像，图像小鼠同时屏蔽发送/接收无线电频率（RF）在一个共同的磁铁线圈（ 博克等，2003） 。我们特别注重解剖分型，已经表现出了许多小鼠模型的影响，在我们的成像中心的高潜力的一个重要的和可访问的应用程序。我们可以提供详细的操作步骤来获得这种图像之前，也有在体内的脑成像（太宰等人 ，2004年）和离体脑成像（春等 ，2007），应注意两个重要的现实考虑。这些在下面讨论。

Watch this Scientific Journal Video about Multiple-mouse Neuroanatomical Magnetic Resonance Imaging at JoVE.com

Multiple-mouse Neuroanatomical Magnetic Resonance Imaging

磁共振成像（MRI）已成为一个日益流行的工具，用于研究的转基因小鼠的表型。本文介绍了必要的方法来实现高通量基因改变使用多个鼠标MRI小鼠的表型。

多鼠神经解剖学磁共振成像

The field of mouse phenotyping with magnetic resonance imaging (MRI) is rapidly growing, motivated by the need for improved tools for characterizing and ...

multiple-mouse-neuroanatomical-magnetic-resonance-imaging

Research

JoVE Journal

Neuroscience

15.7K 次观看.  Hospital for Sick Children. 磁共振成像（MRI）已成为一个日益流行的工具，用于研究的转基因小鼠的表型。本文介绍了必要的方法来实现高通量基因改变使用多个鼠标MRI小鼠的表型。

视频: Multiple-mouse Neuroanatomical Magnetic Resonance Imaging

Magnetic Resonance Spectroscopy of live Drosophila melanogaster using Magic Angle Spinning

High-Resolution Magic Angle Spinning (HRMAS) proton magnetic resonance spectroscopy (1H-MRS) is a novel non-destructive technique that improves spectral line-widths and allows high-resolution spectra to be obtained from extracts, intact cells, cell cultures, and more importantly intact tissue to investigate relationships between metabolites and cellular processes. In vivo HRMAS 1H-MRS studies have yet to be reported in the live fruit fly Drosophila melanogaster. Drosophila, as a simpler genetic organism, allows the multiple biological functions and various evolutionarily conserved signaling pathways to be examined at the whole organism level and it is a useful model for investigating genetics and physiology. To this end, we developed and implemented an in vivo HRMAS 1H-MRS method to investigate live Drosophila at 14.1 T. Here, we outline an HRMAS 1H-MRS protocol for the molecular characterization of Drosophila with a conventional MR spectrometer equipped with an HRMAS probe. This technique is a novel, in vivo, non-destructive Drosophila metabolite measurement approach, which enables the identification of disease biomarkers and thus may contribute to novel therapeutic development.

Magnetic Resonance Spectroscopy of live Drosophila melanogaster using Magic Angle Spinning

This technique enables the use of high-resolution magic angle spinning proton MR spectroscopy (HRMAS 1H-MRS) for molecular characterization of live Drosophila melanogaster with a conventional 14.1 tesla spectrometer equipped with an HRMAS probe.

生活磁共振波谱果蝇</em用魔角旋转

High-Resolution Magic Angle Spinning (HRMAS) proton magnetic resonance spectroscopy (1H-MRS) is a novel non-destructive technique that improves spectral ...

科研

神经科学

High-resolution Functional Magnetic Resonance Imaging Methods for Human Midbrain

Functional MRI (fMRI) is a widely used tool for non-invasively measuring correlates of human brain activity. However, its use has mostly been focused upon measuring activity on the surface of cerebral cortex rather than in subcortical regions such as midbrain and brainstem. Subcortical fMRI must overcome two challenges: spatial resolution and physiological noise. Here we describe an optimized set of techniques developed to perform high-resolution fMRI in human SC, a structure on the dorsal surface of the midbrain; the methods can also be used to image other brainstem and subcortical structures.
High-resolution (1.2 mm voxels) fMRI of the SC requires a non-conventional approach. The desired spatial sampling is obtained using a multi-shot (interleaved) spiral acquisition1. Since, T2* of SC tissue is longer than in cortex, a correspondingly longer echo time (TE ~ 40 msec) is used to maximize functional contrast. To cover the full extent of the SC, 8-10 slices are obtained. For each session a structural anatomy with the same slice prescription as the fMRI is also obtained, which is used to align the functional data to a high-resolution reference volume.
In a separate session, for each subject, we create a high-resolution (0.7 mm sampling) reference volume using a T1-weighted sequence that gives good tissue contrast. In the reference volume, the midbrain region is segmented using the ITK-SNAP software application2. This segmentation is used to create a 3D surface representation of the midbrain that is both smooth and accurate3. The surface vertices and normals are used to create a map of depth from the midbrain surface within the tissue4.
Functional data is transformed into the coordinate system of the segmented reference volume. Depth associations of the voxels enable the averaging of fMRI time series data within specified depth ranges to improve signal quality. Data is rendered on the 3D surface for visualization.
In our lab we use this technique for measuring topographic maps of visual stimulation and covert and overt visual attention within the SC1. As an example, we demonstrate the topographic representation of polar angle to visual stimulation in SC.

This article describes techniques to perform high-resolution functional magnetic resonance imaging with 1.2 mm sampling in human midbrain and subcortical structures using a 3T scanner. Use of these techniques to resolve topographic maps of visual stimulation in the human superior colliculus (SC) is given as an example.

高分辨率人类中脑功能磁共振成像方法

Functional MRI (fMRI) is a widely used tool for non-invasively measuring correlates of human brain activity. However, its use has mostly been focused upon ...

The Use of Magnetic Resonance Spectroscopy as a Tool for the Measurement of Bi-hemispheric Transcranial Electric Stimulation Effects on Primary Motor Cortex Metabolism

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of neurological and psychiatric disorders such as stroke and depression. Yet, the mechanisms underlying its ability to modulate brain excitability to improve clinical symptoms remains poorly understood 33. To help improve this understanding, proton magnetic resonance spectroscopy (1H-MRS) can be used as it allows the in vivo quantification of brain metabolites such as &#947;-aminobutyric acid (GABA) and glutamate in a region-specific manner 41. In fact, a recent study demonstrated that 1H-MRS is indeed a powerful means to better understand the effects of tDCS on neurotransmitter concentration 34. This article aims to describe the complete protocol for combining tDCS (NeuroConn MR compatible stimulator) with 1H-MRS at 3 T using a MEGA-PRESS sequence. We will describe the impact of a protocol that has shown great promise for the treatment of motor dysfunctions after stroke, which consists of bilateral stimulation of primary motor cortices 27,30,31. Methodological factors to consider and possible modifications to the protocol are also discussed.

This article aims to describe a basic protocol for combining transcranial direct current stimulation (tDCS) with proton magnetic resonance spectroscopy (1H-MRS) measurements to investigate the effects of bilateral stimulation on primary motor cortex metabolism.

磁共振波谱的用途，用于对初级运动皮层新陈代谢双半球经颅电刺激效果的测量工具一

Transcranial direct current stimulation (tDCS) is a neuromodulation technique that has been increasingly used over the past decade in the treatment of ...

High-resolution In Vivo Manual Segmentation Protocol for Human Hippocampal Subfields Using 3T Magnetic Resonance Imaging

The human hippocampus has been broadly studied in the context of memory and normal brain function and its role in different neuropsychiatric disorders has been heavily studied. While many imaging studies treat the hippocampus as a single unitary neuroanatomical structure, it is, in fact, composed of several subfields that have a complex three-dimensional geometry. As such, it is known that these subfields perform specialized functions and are differentially affected through the course of different disease states. Magnetic resonance (MR) imaging can be used as a powerful tool to interrogate the morphology of the hippocampus and its subfields. Many groups use advanced imaging software and hardware (&#62;3T) to image the subfields; however this type of technology may not be readily available in most research and clinical imaging centers. To address this need, this manuscript provides a detailed step-by-step protocol for segmenting the full anterior-posterior length of the hippocampus and its subfields: cornu ammonis (CA) 1, CA2/CA3, CA4/dentate gyrus (DG), strata radiatum/lacunosum/moleculare (SR/SL/SM), and subiculum. This protocol has been applied to five subjects (3F, 2M; age 29-57, avg. 37). Protocol reliability is assessed by resegmenting either the right or left hippocampus of each subject and computing the overlap using the Dice&#39;s kappa metric. Mean Dice&#39;s kappa (range) across the five subjects are: whole hippocampus, 0.91 (0.90-0.92); CA1, 0.78 (0.77-0.79); CA2/CA3, 0.64 (0.56-0.73); CA4/dentate gyrus, 0.83 (0.81-0.85); strata radiatum/lacunosum/moleculare, 0.71 (0.68-0.73); and subiculum 0.75 (0.72-0.78). The segmentation protocol presented here provides other laboratories with a reliable method to study the hippocampus and hippocampal subfields in vivo using commonly available MR tools.

High-resolution In Vivo Manual Segmentation Protocol for Human Hippocampal Subfields Using 3T Magnetic Resonance Imaging

The goal of this manuscript is to study the hippocampus and hippocampal subfields using MRI. The manuscript describes a protocol for segmenting the hippocampus and five hippocampal substructures: cornu ammonis (CA) 1, CA2/CA3, CA4/dentate gyrus, strata radiatum/lacunosum/moleculare, and subiculum.

高分辨率<em&gt;在体内</em&gt;使用3T磁共振成像手动分割协议为人类海马子字段

The human hippocampus has been broadly studied in the context of memory and normal brain function and its role in different neuropsychiatric disorders has ...

High-resolution Structural Magnetic Resonance Imaging of the Human Subcortex In Vivo and Postmortem

The focus of this study was to test the resolution limits of structural MRI of a postmortem brain compared to living human brains. The resolution of structural MRI in vivo is ultimately limited by physiological noise, including pulsation, respiration and head movement. Although imaging hardware continues to improve, it is still difficult to resolve structures on the millimeter scale. For example, the primary visual sensory pathways synapse at the lateral geniculate nucleus (LGN), a visual relay and control nucleus in the thalamus that normally is organized into six interleaved monocular layers. Neuroimaging studies have not been able to reliably distinguish these layers due their small size that are less than 1 mm thick.
The resolving limit of structural MRI, in a postmortem brain was tested using multiple images averaged over a long duration (~24 h). The purpose was to test whether it was possible to resolve the individual layers of the LGN in the absence of physiological noise. A proton density (PD)1 weighted pulse sequence was used with varying resolution and other parameters to determine the minimum number of images necessary to be registered and averaged to reliably distinguish the LGN and other subcortical regions. The results were also compared to images acquired in living human brains. In vivo subjects were scanned in order to determine the additional effects of physiological noise on the minimum number of PD scans needed to differentiate subcortical structures, useful in clinical applications.

High-resolution Structural Magnetic Resonance Imaging of the Human Subcortex In Vivo and Postmortem

Here we present a protocol to determine the minimum number images that needed to be registered and averaged to resolve subcortical structures and test whether the individual layers of the LGN could be resolved in the absence of physiological noise.

高分辨率结构磁共振人类皮质下的成像<I&gt;在体内</I&gt;与死亡

The focus of this study was to test the resolution limits of structural MRI of a postmortem brain compared to living human brains. The resolution of ...

A Magnetic Resonance Imaging Protocol for Stroke Onset Time Estimation in Permanent Cerebral Ischemia

MRI provides a sensitive and specific imaging tool to detect acute ischemic stroke by means of a reduced diffusion coefficient of brain water. In a rat model of ischemic stroke, differences in quantitative T1 and T2 MRI relaxation times (qT1 and qT2) between the ischemic lesion (delineated by low diffusion) and the contralateral non-ischemic hemisphere increase with time from stroke onset. The time dependency of MRI relaxation time differences is heuristically described by a linear function and thus provides a simple estimate of stroke onset time. Additionally, the volumes of abnormal qT1 and qT2 within the ischemic lesion increase linearly with time providing a complementary method for stroke timing. A (semi)automated computer routine based on the quantified diffusion coefficient is presented to delineate acute ischemic stroke tissue in rat ischemia. This routine also determines hemispheric differences in qT1 and qT2 relaxation times and the location and volume of abnormal qT1 and qT2 voxels within the lesion. Uncertainties associated with onset time estimates of qT1 and qT2 MRI data vary from &plusmn; 25 min to &plusmn; 47 min for the first 5 hours of stroke. The most accurate onset time estimates can be obtained by quantifying the volume of overlapping abnormal qT1 and qT2 lesion volumes, termed 'Voverlap' (&plusmn; 25 min) or by quantifying hemispheric differences in qT2 relaxation times only (&plusmn; 28 min). Overall, qT2 derived parameters outperform those from qT1. The current MRI protocol is tested in the hyperacute phase of a permanent focal ischemia model, which may not be applicable to transient focal brain ischemia.

A protocol for stroke onset time estimation in a rat model of stroke exploiting quantitative magnetic resonance imaging (qMRI) parameters is described. The procedure exploits diffusion MRI for delineation of the acute stroke lesion and quantitative T1 and T2 (qT1 and qT2) relaxation times for timing of stroke.

脑缺血中风发作时间估计的磁共振成像协议

MRI provides a sensitive and specific imaging tool to detect acute ischemic stroke by means of a reduced diffusion coefficient of brain water. In a rat ...

Diffusion Tensor Magnetic Resonance Imaging in Chronic Spinal Cord Compression

Chronic spinal cord compression is the most common cause of spinal cord impairment in patients with nontraumatic spinal cord damage. Conventional magnetic resonance imaging (MRI) plays an important role in both confirming the diagnosis and evaluating the degree of compression. However, the anatomical detail provided by conventional MRI is not sufficient to accurately estimate neuronal damage and/or assess the possibility of neuronal recovery in chronic spinal cord compression patients. In contrast, diffusion tensor imaging (DTI) can provide quantitative results according to the detection of water molecule diffusion in tissues. In the present study, we develop a methodological framework to illustrate the application of DTI in chronic spinal cord compression disease. DTI fractional anisotropy (FA), apparent diffusion coefficients (ADCs), and eigenvector values are useful for visualizing microstructural pathological changes in the spinal cord. Decreased FA and increases in ADCs and eigenvector values were observed in chronic spinal cord compression patients compared to healthy controls. DTI could help surgeons understand spinal cord injury severity and provide important information regarding prognosis and neural functional recovery. In conclusion, this protocol provides a sensitive, detailed, and noninvasive tool to evaluate spinal cord compression.

Here, we present a protocol for the application of diffusion tensor imaging parameters to evaluate spinal cord compression.

扩散张量磁共振成像在慢性脊髓压迫中的应用

Chronic spinal cord compression is the most common cause of spinal cord impairment in patients with nontraumatic spinal cord damage. Conventional magnetic ...

Standardized Data Acquisition for Neuromelanin-Sensitive Magnetic Resonance Imaging of the Substantia Nigra

The dopaminergic system plays a crucial role in healthy cognition (e.g., reward learning and uncertainty) and neuropsychiatric disorders (e.g., Parkinson's disease and schizophrenia). Neuromelanin is a byproduct of dopamine synthesis that accumulates in dopaminergic neurons of the substantia nigra. Neuromelanin-sensitive magnetic resonance imaging (NM-MRI) is a noninvasive method for measuring neuromelanin in those dopaminergic neurons, providing a direct measure of dopaminergic cell loss in the substantia nigra and a proxy measure of dopamine function. Although NM-MRI has been shown to be useful for studying various neuropsychiatric disorders, it is challenged by a limited field-of-view in the inferior-superior direction resulting in the potential loss of data from the accidental exclusion of part of the substantia nigra. In addition, the field is lacking a standardized protocol for the acquisition of NM-MRI data, a critical step in facilitating large-scale multisite studies and translation into the clinic. This protocol describes a step-by-step NM-MRI volume placement procedure and online quality control checks to ensure the acquisition of good-quality data covering the entire substantia nigra.

This protocol shows how to acquire neuromelanin-sensitive magnetic resonance imaging data of the substantia nigra.

黑质神经黑色素敏感磁共振成像的标准化数据采集

The dopaminergic system plays a crucial role in healthy cognition (e.g., reward learning and uncertainty) and neuropsychiatric disorders (e.g., ...

Acquisition of Resting-State Functional Magnetic Resonance Imaging Data in the Rat

Resting-state functional magnetic resonance imaging (rs-fMRI) has become an increasingly popular method to study brain function in a resting, non-task state. This protocol describes a preclinical survival method for obtaining rs-fMRI data. Combining low dose isoflurane with continuous infusion of the &#945;2 adrenergic receptor agonist dexmedetomidine provides a robust option for stable, high-quality data acquisition while preserving brain network function. Furthermore, this procedure allows for spontaneous breathing and near-normal physiology in the rat. Additional imaging sequences can be combined with resting-state acquisition creating experimental protocols with anesthetic stability of up to 5 h using this method. This protocol describes the setup of equipment, monitoring of rat physiology during four distinct phases of anesthesia, acquisition of resting-state scans, quality assessment of data, recovery of the animal, and a brief discussion of post-processing data analysis. This protocol can be used across a wide variety of preclinical rodent models to help reveal the resulting brain network changes that occur at rest.

This protocol describes a method for obtaining stable resting-state functional magnetic resonance imaging (rs-fMRI) data from a rat using low dose isoflurane in combination with low dose dexmedetomidine.

获取大鼠的静态功能磁共振成像数据

Resting-state functional magnetic resonance imaging (rs-fMRI) has become an increasingly popular method to study brain function in a resting, non-task ...

Endovascular Perforation Model for Subarachnoid Hemorrhage Combined with Magnetic Resonance Imaging (MRI)

The endovascular filament perforation model to mimic subarachnoid hemorrhage (SAH) is a commonly used model - however, the technique can cause a high mortality rate as well as an uncontrollable volume of SAH and other intracranial complications such as stroke or intracranial hemorrhage. In this protocol, a standardized SAH mouse model is presented, induced by endovascular filament perforation, combined with magnetic resonance imaging (MRI) 24 h after operation to ensure the correct bleeding site and exclude other relevant intracranial pathologies. Briefly, C57BL/6J mice are anesthetized with an intraperitoneal ketamine/xylazine (70 mg/16 mg/kg body weight) injection and placed in a supine position. After midline neck incision, the common carotid artery (CCA) and carotid bifurcation are exposed, and a 5-0 non-absorbable monofilament polypropylene suture is inserted in a retrograde fashion into the external carotid artery (ECA) and advanced into the common carotid artery. Then, the filament is invaginated into the internal carotid artery (ICA) and pushed forward to perforate the anterior cerebral artery (ACA). After recovery from surgery, mice undergo a 7.0 T MRI 24 h later. The volume of bleeding can be quantified and graded via postoperative MRI, enabling a robust experimental SAH group with the option to perform further subgroup analyses based on blood quantity.

Endovascular Perforation Model for Subarachnoid Hemorrhage Combined with Magnetic Resonance Imaging MRI

Here we present a standardized SAH mouse model, induced by endovascular filament perforation, combined with magnetic resonance imaging (MRI) 24 h after operation to ensure the correct bleeding site and exclude other relevant intracranial pathologies.

蛛网膜下腔出血结合磁共振成像（MRI）的血管内穿孔模型

The endovascular filament perforation model to mimic subarachnoid hemorrhage (SAH) is a commonly used model - however, the technique can cause a high ...