In-vivo probabilistic atlas of human thalamic nuclei based on diffusion- weighted magnetic resonance imaging

Abstract

The thalamic nuclei are involved in many neurodegenerative diseases and therefore, their identification is of key importance in numerous clinical treatments. Automated segmentation of thalamic subparts is currently achieved by exploring diffusion-weighted magnetic resonance imaging (DW-MRI), but in absence of such data, atlas-based segmentation can be used as an alternative. Currently, there is a limited number of available digital atlases of the thalamus. Moreover, all atlases are created using a few subjects only, thus are prone to errors due to the inter-subject variability of the thalamic morphology. In this work, we present a probabilistic atlas of anatomical subparts of the thalamus built upon a relatively large dataset where the individual thalamic parcellation was done by employing a recently proposed automatic diffusion-based clustering method. Our analyses, comparing the segmentation performance between the atlas-based and the clustering method, demonstrate the ability of the provided atlas to substitute the automated diffusion-based subdivision in the individual space when the DW-MRI is not available.

Partial‐volume modeling reveals reduced gray matter in specific thalamic nuclei early in the time course of psychosis and chronic schizophrenia

“…Today, there are few available methods to automatically parcellate the thalamic nuclei based on local structural imaging features (Iglesias et al, 2018; Najdenovska et al, 2018; Su et al, 2019). To our knowledge, none of them has previously been used for the GM analysis in early psychosis or schizophrenia.…”

Effects of genetic variability of CYP2D6 on neural substrates of sustained attention during on-task activity

“…Other networks involved in the effect of genotype included specific cortical areas involved in sustained attention tasks, such as the middle and inferior right frontal gyri, as well as in the functionally relevant subcortical structures of the anterior striatum/basal forebrain (Paus et al 1997(Paus et al , 2000. We also observed a selective involvement of the thalamus, consisting of a posterior portion (mainly localized to the lateral-posterior group and medial pulvinar) and the ventral-anterior portion (Najdenovska et al 2018). A structural connectivity study by Behrens et al (2003) has shown differential connectivity between thalamic nuclei and broad cortical areas.…”

Cortical and subcortical hemodynamic changes during human sleep slow waves

“…In order to investigate whether this may be true also in humans, here we analyzed and characterized the anatomical and functional nature of thalamic portions recruited during the occurrence of human sleep slow waves ( Figure 4). First, we determined the percentage of activated voxels that fell within specific thalamic substructures identified using a probabilistic atlas of the human thalamus based on diffusion-weighted imaging (Najdenovska et al, 2018). For both the left and the right thalamus, we found that significant BOLD-signal changes especially involved medial nuclei located anteriorly, centrally and posteriorly (Figures 4D-E).…”

“…Specific analyses were performed to characterize the anatomical and functional nature of thalamic and cerebellar portions recruited during the occurrence of human sleep slow waves. First, anatomical atlases were used to determine the relative distribution (percentage) of activated voxels with respect to thalamic (probabilistic atlas based on diffusion-weighted imaging; Najdenovska et al, 2018) and cerebellar (SUIT atlas; Diedrichsen et al, 2011Diedrichsen et al, , 2009 subdivisions. Then, thalamic and cerebellar connectivity maps were generated and used to determine the preferential functional connectivity of activated voxels with respect to the seven canonical cortical networks defined on the basis of cortical intrinsic functional connectivity (Yeo et al, 2011): visual, somatomotor, dorsal attention, ventral attention, limbic, fronto-parietal and default mode.…”