Department of Neurology, University of Duisburg-Essen, Hufelandstrasse 55, Essen, Germany.
Cerebellum. 2012 Jun;11(2):314-24. doi: 10.1007/s12311-010-0194-5.
The present review focuses on recent developments in structural and functional magnetic resonance imaging (MRI) of the deep cerebellar nuclei (DCN), the main output structure of the cerebellum. The high iron content in the DCN allows for their visibility in T2*-weighted images. Spatial resolution has improved allowing the identification of DCN in individual cerebellar patients and healthy subjects. Based on findings in larger groups of healthy subjects, probabilistic MRI-based atlases of the deep cerebellar nuclei have been developed, which are important tools in human lesion and functional imaging studies. High iron content in the DCN, on the other hand, decreases the blood oxygenation level dependent-signal making functional imaging a difficult challenge. Compared to the vast amount of studies reporting activation of the cerebellar cortex, the number of studies demonstrating activation of the DCN is much less. Most studies report activation of the dentate nucleus. Dentate activations appear to be more reliable in more complex tasks for reasons currently unknown. As yet, few studies tried to show activations of functional subunits of the dentate nucleus. Increased signal-to-noise ratio and better spatial resolution using higher MR field strength together with recent progress in dentate normalization methods will allow identification of functional subunits and their interactions with the cerebellar cortex in future studies.
本综述重点介绍了小脑深部核（DCN）的结构和功能磁共振成像（MRI）的最新进展，小脑深部核是小脑的主要输出结构。DCN 中的高铁含量使其在 T2*-加权图像中可见。空间分辨率的提高使得能够在个体小脑患者和健康受试者中识别 DCN。基于对更大组健康受试者的发现，已经开发了基于概率 MRI 的深部小脑核图谱，这是人类病变和功能成像研究的重要工具。另一方面，DCN 中的高铁含量降低了血氧水平依赖信号，使得功能成像成为一项具有挑战性的任务。与大量报告小脑皮层激活的研究相比，证明 DCN 激活的研究数量要少得多。大多数研究报告了齿状核的激活。由于目前尚不清楚原因，齿状核激活在更复杂的任务中似乎更可靠。迄今为止，很少有研究试图显示齿状核功能亚单位的激活。使用更高的磁共振场强提高信噪比和更好的空间分辨率，以及最近在齿状核归一化方法方面的进展，将允许在未来的研究中识别功能亚单位及其与小脑皮层的相互作用。
