A frameless stereotaxic MRI technique for macaque neuroscience studies.
A frameless stereotaxic MRI technique for macaque neuroscience studies.
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DOI：
10.2174/1874440001105010198
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Scadeng M
中科院分区：
文献类型：
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作者：
Dubowitz DJ;Scadeng M
MRI已广泛用于非人类灵长类动物研究的预先计划神经科学程序。然而，在立体定位空间中定向成像研究主要依赖于使用立体定位框架或将基准标记与神经成像共配准。在这项研究中，我们提出了一种简单的方法，其中MRI数据集与定义法兰克福立体定位基线平面的骨性标志对齐，而不需要立体定位框架或额外的外部基准。为了便于在MRI扫描上定位骨性标志（眶下缘、外耳道），讨论了其他成像标志（中眼平面、颞下颌关节），这些标志提供了补充和容易看到的参考点。 本文应用0.7mm各向同性分辨率的3D快速梯度回波MRI图像，对8只恒河猴进行了无框架MRI立体定位技术的评价。1)比较了传统立体定位框架和无框架MRI技术（n=2）之间基准标记物的立体定位坐标的差异。2)比较了无框架MRI技术和将动物置于MRI兼容立体定位框架中获得的MRI（n=4）之间脑区立体定位坐标的差异。3)进一步完善了无框架MRI技术，以相对于电极微驱动器的立体定位坐标在硬脑膜记录室内规定电极穿透。将MRI坐标的差异与电极微驱动器进行比较（n=3）。 无框架MRI技术和传统立体定位框架之间基准标记的平均定位相差1.6 +/- 0.6 mm。在无框架技术和MRI兼容的立体定位框架之间，大脑解剖结构的定位相差2.8 +/- 2.2 mm，主要误差来源是矢状面上仰旋转。去除旋转后，定位差异降至0.5 +/- 0.6 mm。硬脑膜记录腔内电极束的无框MRI坐标在电极微驱动器读数的0.5 mm +/- 0.2 mm范围内。 这种简单的技术提供了在个体动物中准确计划手术和神经生理记录的能力，并使用可获得的软件来定义大脑解剖结构和电极或注射道的位置，而不需要专用的MRI兼容定位硬件。对深度麻醉的需求减少（传统立体定位框架的必要性）使得该技术更适合功能性MRI研究。由于每只动物都提供了骨性标志来定义自己的立体定位空间，因此该技术很容易适用于其他物种。
MRI has achieved widespread use for preplanning neuroscience procedures for non-human primate studies. However, orienting imaging studies in stereotaxic space has relied primarily on using a stereotaxic frame or co-registering fiducial markers with the neuroimaging. In this study, we present a simple approach in which the MRI dataset is aligned to the bony landmarks that define the Frankfurt stereotaxic baseline plane, without the need for a stereotaxic frame or additional external fiducials. To facilitate localizing the bony landmarks (infraorbital margin, external bony auditory meatus) on the MRI scans additional imaging landmarks (mid ocular plane, temporomandibular joint) are discussed that provide supplementary and readily visible points of reference. The frameless MRI stereotaxic technique was evaluated in 8 rhesus macaque monkeys using 3D fast gradient echo MRI images with 0.7mm isotropic resolution. 1) Difference in stereotaxic coordinates of fiducial markers was compared between a traditional stereotaxic frame and the frameless MRI technique (n=2). 2) Differences in stereotaxic coordinates for cerebral regions were compared between the frameless MRI technique and MRI obtained with the animal positioned in a MRI-compatible stereotaxic frame (n=4). 3) The frameless MRI technique was further refined to prescribe electrode penetrations within a dural recording chamber in stereotaxic coordinates relative to the electrode microdrive. Differences in MRI coordinates were compared with the electrode microdrive (n=3). Mean localization of fiducial markers differed by 1.6 +/- 0.6 mm between the frameless MRI technique and a traditional stereotaxic frame. Between the frameless technique and an MRI-compatible stereotaxic frame, localization of cerebral anatomy differed by 2.8 +/- 2.2 mm with the primary source of error being a pitch-up rotation in the sagittal plane. This localization difference was reduced to 0.5 +/- 0.6 mm when this rotation was removed. Frameless MRI coordinates for electrode tracts within the dural recording chamber were within 0.5mm +/- 0.2 mm of the electrode microdrive readings. This simple technique provides the ability to accurately plan surgery and neurophysiological recordings in an individual animal, and to define the location of cerebral anatomy and electrode or injection tracts using publically available software, and without the need for dedicated MRI-compatible localization hardware. The reduced need for deep anesthesia (a necessity with traditional stereotaxic frames) makes the technique more amenable for functional MRI studies. Since each animal provides the bony landmarks to define their own stereotaxic space, this technique is readily applicable to other species.