title: Diffusion tensor imaging of the human cerebellar pathways and their interplay with cerebral macrostructure.
abstract: Cerebellar white matter (WM) connections to the central nervous system are classified functionally into the Spinocerebellar (SC), vestibulocerebellar (VC), and cerebrocerebellar subdivisions. The SC pathways project from spinal cord to cerebellum, whereas the VC pathways project from vestibular organs of the inner ear. Cerebrocerebellar connections are composed of feed forward and feedback connections between cerebrum and cerebellum including the cortico-ponto-cerebellar (CPC) pathways being of cortical origin and the dentate-rubro-thalamo-cortical (DRTC) pathway being of cerebellar origin. In this study we systematically quantified the whole cerebellar system connections using diffusion tensor magnetic resonance imaging (DT-MRI). Ten right-handed healthy subjects (7 males and 3 females, age range 20-51 years) were studied. DT-MRI data were acquired with a voxel size = 2 mm × 2 mm × 2 mm at a 3.0 Tesla clinical MRI scanner. The DT-MRI data were prepared and analyzed using anatomically-guided deterministic tractography methods to reconstruct the SC, DRTC, fronto-ponto-cerebellar (FPC), parieto-ponto-cerebellar (PPC), temporo-ponto-cerebellar (TPC) and occipito-ponto-cerebellar (OPC). The DTI-attributes or the cerebellar tracts along with their cortical representation (Brodmann areas) were presented in standard Montréal Neurological Institute space. All cerebellar tract volumes were quantified and correlated with volumes of cerebral cortical, subcortical gray matter (GM), cerebral WM and cerebellar GM, and cerebellar WM. On our healthy cohort, the ratio of total cerebellar GM-to-WM was ~3.29 ± 0.24, whereas the ratio of cerebral GM-to-WM was approximately 1.10 ± 0.11. The sum of all cerebellar tract volumes is ~25.8 ± 7.3 mL, or a percentage of 1.6 ± 0.45 of the total intracranial volume (ICV).
authors.affiliation: Department of Physical Medicine and Rehabilitation and TIRR Memorial Hermann Neuro-Recovery Research Center, University of Texas Health Science Center Houston Houston, TX, USA.
authors.forename: Zafer
authors.initials: Z
authors.lastname: Keser
authors.affiliation: Department of Diagnostic and Interventional Radiology, University of Texas Health Science Center at Houston Houston, TX, USA.
authors.forename: Khader M
authors.initials: KM
authors.lastname: Hasan
authors.affiliation: UT Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, University of Texas Health Science Center Houston, TX, USA.
authors.forename: Benson I
authors.initials: BI
authors.lastname: Mwangi
authors.affiliation: Department of Diagnostic Radiology, Division of Neuroradiology, Johns Hopkins University Baltimore, MD, USA.
authors.forename: Arash
authors.initials: A
authors.lastname: Kamali
authors.affiliation: Department of Diagnostic Radiology, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center Houston, TX, USA.
authors.forename: Fehime Eymen
authors.initials: FE
authors.lastname: Ucisik-Keser
authors.affiliation: Department of Diagnostic and Interventional Radiology, University of Texas Health Science Center at Houston Houston, TX, USA.
authors.forename: Roy F
authors.initials: RF
authors.lastname: Riascos
authors.affiliation: Department of Physical Medicine and Rehabilitation and TIRR Memorial Hermann Neuro-Recovery Research Center, University of Texas Health Science Center Houston Houston, TX, USA.
authors.forename: Nuray
authors.initials: N
authors.lastname: Yozbatiran
authors.affiliation: Department of Physical Medicine and Rehabilitation and TIRR Memorial Hermann Neuro-Recovery Research Center, University of Texas Health Science Center Houston Houston, TX, USA.
authors.forename: Gerard E
authors.initials: GE
authors.lastname: Francisco
authors.affiliation: Department of Diagnostic and Interventional Radiology, University of Texas Health Science Center at Houston Houston, TX, USA.
authors.forename: Ponnada A
authors.initials: PA
authors.lastname: Narayana
keywords: cerebellum; cerebral-cerebellar volumes; cortical thickness; cortico-ponto-cerebellar; dentate-rubro-thalamo-cortical; diffusion tensor tractography; spinocerebellar