Shepherd Timothy M, Hoch Michael J, Bruno Mary, Faustin Arline, Papaioannou Antonios, Jones Stephen E, Devinsky Orrin, Wisniewski Thomas
Department of Radiology, New York University, New York, NY, United States.
Center for Advanced Imaging Innovation and Research (CAI2R), New York, NY, United States.
Front Neuroanat. 2020 Mar 19;14:9. doi: 10.3389/fnana.2020.00009. eCollection 2020.
Clinically relevant neuroanatomy is challenging to teach, learn and remember since many functionally important structures are visualized best using histology stains from serial 2D planar sections of the brain. In clinical patients, the locations of specific structures then must be inferred from spatial position and surface anatomy. A 3D MRI dataset of neuroanatomy has several advantages including simultaneous multi-planar visualization in the same brain, direct end-user manipulation of the data and image contrast identical to clinical MRI. We created 3D MRI datasets of the postmortem brain with high spatial and contrast resolution for simultaneous multi-planar visualization of complex neuroanatomy.
Whole human brains ( = 6) were immersion-fixed in 4% formaldehyde for 4 weeks, then washed continuously in water for 48 h. The brains were imaged on a clinical 3-T MRI scanner with a 64-channel head and neck coil using a 3D T2-weighted sequence with 400-micron isotropic resolution (voxel = 0.064 mm; time = 7 h). Besides resolution, this sequence has multiple adjustments to improve contrast compared to a clinical protocol, including 93% reduced turbo factor and 77% reduced effective echo time.
This MRI microscopy protocol provided excellent contrast resolution of small nuclei and internal myelinated pathways within the basal ganglia, thalamus, brainstem, and cerebellum. Contrast was sufficient to visualize the presence and variation of horizontal layers in the cerebral cortex. 3D isotropic resolution datasets facilitated simultaneous multi-planar visualization and efficient production of specific tailored oblique image orientations to improve understanding of complex neuroanatomy.
We created an unlabeled high-resolution digital 3D MRI dataset of neuroanatomy as an online resource for readers to download, manipulate, annotate and use for clinical practice, research, and teaching that is complementary to traditional histology-based atlases. Digital MRI contrast is quantifiable, reproducible across brains and could help validate novel MRI strategies for structure visualization.
临床相关神经解剖学在教学、学习和记忆方面具有挑战性，因为许多功能重要的结构在使用大脑连续二维平面切片的组织学染色时能得到最佳显示。在临床患者中，特定结构的位置必须从空间位置和表面解剖结构推断出来。神经解剖学的三维磁共振成像（MRI）数据集有几个优点，包括在同一大脑中同时进行多平面可视化、数据的直接最终用户操作以及与临床MRI相同的图像对比度。我们创建了具有高空间和对比度分辨率的死后大脑三维MRI数据集，用于复杂神经解剖学的同时多平面可视化。
完整的人脑（n = 6）浸入4%甲醛中固定4周，然后在水中连续冲洗48小时。使用具有64通道头颈部线圈的临床3-T MRI扫描仪，采用各向同性分辨率为400微米（体素 = 0.064立方毫米；时间 = 7小时）的三维T2加权序列对大脑进行成像。除了分辨率外，与临床方案相比，该序列还有多项调整以改善对比度，包括将涡轮因子降低93%和将有效回波时间降低77%。
这种MRI显微镜检查方案提供了基底神经节、丘脑、脑干和小脑中的小核团和内部有髓神经通路的出色对比度分辨率。对比度足以显示大脑皮层水平层的存在和变化。三维各向同性分辨率数据集便于同时进行多平面可视化，并能高效生成特定定制的斜向图像方向，以增进对复杂神经解剖学的理解。
我们创建了一个未标记的高分辨率神经解剖学数字三维MRI数据集，作为在线资源供读者下载、操作、注释并用于临床实践、研究和教学，它是对传统基于组织学的图谱的补充。数字MRI对比度是可量化的，在不同大脑之间具有可重复性，并且有助于验证用于结构可视化的新型MRI策略。
