In vivo Assessment of the Cerebellum by Novel MRI Techniques and Application to Hereditary Ataxias: Morphological, Pathoanatomical and Clinical Aspects

这项由大学诊所Essen和耶拿大学医院的合作伙伴开展的合作项目的目的是，通过使用新的MRI技术，包括定量敏感性图、轴突方向弥散和密度图以及基于扩散的纤维束成像，更深入地了解常见形式的退行性共济失调小脑核的病理解剖。将在活体内研究健康人和遗传性(即Friedreichs共济失调、脊髓小脑性共济失调1、2、3、6和17型)和非遗传性退行性共济失调(即散发性成人共济失调，病因不明，多系统萎缩-小脑型)患者的小脑核团及其神经纤维联系。将比较不同类型共济失调患者与疾病相关的核团体积和铁含量的变化，以及传入和传出纤维连接的变化。此外，还将评估这些标记物在退行性共济失调的诊断和后续检查中的可能临床应用。这些病理解剖学和临床方面的答案得到方法学发展的支持，这些发展包括自动和稳健地分割小脑核，收集其体积和磁化率(铁含量的指标)的随年龄变化的规范性参考数据，以及生成小脑核团和白质纤维束的概率图谱，以便于MRI数据的自动分析。

The aim of this collaboration project between the two partners from the University Clinic Essen and the Jena University Hospital is to obtain deeper insight into the pathoanatomy of cerebellar nuclei in common forms of degenerative ataxias by using novel MRI techniques, including quantitative susceptibility mapping, neurite orientation dispersion and density mapping, and diffusion-based fiber tractography. Cerebellar nuclei and their neuronal fiber connections will be studied in vivo in healthy subjects and in patients with hereditary (i.e., Friedreich`s ataxia, spinocerebellar ataxias type 1, 2, 3, 6, and 17) and nonhereditary degenerative ataxias (i.e., sporadic onset adult ataxia of unknown etiology, multi system atrophy - cerebellar type). Disease-related changes in volume and iron content of the nuclei as well as alterations in their afferent and efferent fiber connections will be compared between the different types of ataxia. In addition, possible clinical applications of these markers will be evaluated for the diagnosis and follow-up examination of degenerative ataxias. Answering these pathoanatomical and clinical aspects is supported by methodological developments that include automatic and robust segmentation of the cerebellar nuclei, collection of age-dependent normative reference data of their volume and magnetic susceptibility (an indicator for iron content), and the generation of probabilistic atlases of the nuclei and the white matter fiber tracts of the cerebellum to facilitate automatic analysis of MRI data.