Strotmann Barbara, Heidemann Robin M, Anwander Alfred, Weiss Marcel, Trampel Robert, Villringer Arno, Turner Robert
Department of Neurophysics, Max-Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
J Magn Reson Imaging. 2014 Apr;39(4):1018-26. doi: 10.1002/jmri.24252. Epub 2013 Nov 20.
To investigate the feasibility of discriminating the habenula in human brain using high-resolution structural MRI and diffusion-weighted imaging at 7 Tesla (T).
MRI experiments included a MP2RAGE and GRE sequence to acquire quantitative parameter maps of T1, T2*, and a calculated proton density map and the combined approach of zoomed and parallel imaging (ZOOPPA) to obtain dw images. Probabilistic tractography algorithms were used to identify multiple fiber orientations in submillimetre voxels, and constrained spherical deconvolution to resolve orientations in regions where fibers cross.
Maps of T1, T2*, and proton density showed high contrast of the human habenula. The lateral habenula and its commissure can be distinguished from medial habenula and adjacent tissue. DWI data with 0.7 mm isotropic resolution revealed that fiber populations differ in medial and lateral habenula and two major fiber bundles that connect habenular nuclei with forebrain structures and brainstem.
High resolution 7T MR imaging of the human habenula provides sufficient signal-to-noise and contrast to enable identification of the lateral and medial nuclei. In vivo high resolution DWI at 7T is able to distinguish between lateral and medial habenula, and to detect major fiber tracts that connect the habenula with other brain areas.
探讨使用7特斯拉（T）高分辨率结构磁共振成像（MRI）和扩散加权成像鉴别人类大脑缰核的可行性。
MRI实验包括一个MP2RAGE序列和GRE序列，用于获取T1、T2*的定量参数图以及计算得到的质子密度图，还有采用缩放并行成像（ZOOPPA）的联合方法来获取扩散加权（dw）图像。概率性纤维束成像算法用于识别亚毫米体素中的多种纤维方向，并采用约束球形反卷积来解析纤维交叉区域的方向。
T1、T2*和质子密度图显示出人类缰核的高对比度。外侧缰核及其连合可与内侧缰核及相邻组织区分开来。具有0.7毫米各向同性分辨率的扩散加权成像（DWI）数据显示，内侧和外侧缰核中的纤维群不同，并且有两条主要纤维束将缰核与前脑结构和脑干相连。
人类缰核的高分辨率7T MR成像提供了足够的信噪比和对比度，能够识别外侧和内侧核。7T的体内高分辨率DWI能够区分外侧和内侧缰核，并检测将缰核与其他脑区相连的主要纤维束。
