In vivo Probabilistic Structural Atlas of the Inferior and Superior Colliculi, Medial and Lateral Geniculate Nuclei and Superior Olivary Complex in Humans Based on 7 Tesla MRI

Abstract

Despite extensive neuroimaging research of primary sensory cortices involved in auditory and visual functions, subcortical structures within these domains, such as the inferior and superior colliculi, the medial and lateral geniculate nuclei and the superior olivary complex, are currently understudied with magnetic resonance imaging (MRI) in living humans. This is because a precise localization of these nuclei is hampered by the limited contrast and sensitivity of conventional neuroimaging methods for deep brain nuclei. In this work, we used 7 Tesla multi-modal (T 2 -weighted and diffusion fractional anisotropy) 1.1 mm isotropic resolution MRI to achieve high sensitivity and contrast for single-subject brainstem and thalamic nuclei delineation. After precise coregistration to stereotactic space, we generated an in vivo human probabilistic atlas of auditory (medial geniculate nucleus, inferior colliculus, and superior olivary complex) and visual (lateral geniculate nucleus and superior colliculus) subcortical nuclei. We foresee the use of this atlas as a tool to precisely identify the location and shape of auditory/visual deep nuclei in research as well as clinical human studies.

Probabilistic Template of the Lateral Parabrachial Nucleus, Medial Parabrachial Nucleus, Vestibular Nuclei Complex, and Medullary Viscero-Sensory-Motor Nuclei Complex in Living Humans From 7 Tesla MRI

“…The quantitative validation using the inter-rater agreement and internal consistency of in vivo probabilistic labels provided positive results for all nuclei. The number of subjects in this study was limited; nevertheless, a sample size of 10-12 subjects was enough to achieve significant results in the current as well as previous brain/brainstem template work (Bianciardi et al, 2015(Bianciardi et al, , 2018Croxson et al, 2018;García-Gomar et al, 2019). Comparison of the probabilistic label volume with the volume derived from the Paxinos histologybased atlas drawings (Olszewski and Baxter, 1954) was quite good for MPB, Ve, and VSM, yet there was some mismatch for LPB.…”

Regionconnect: Rapidly extracting standardized brain connectivity information in voxel-wise neuroimaging studies

“…Since the accuracy of regionconnect directly depends on the accuracy of registration to the IIT space, it should also be noted that registration to the IIT diffusion tensor template has been shown to allow higher spatial normalization accuracy compared to all other available tensor templates, including study-specific templates constructed with state of the art techniques, for both younger and older adults ( Cabeen et al, 2017 ; Zhang and Arfanakis, 2018 ). The diffusion tensor template of the atlas was successfully used for spatial normalization in a study of the effects of tetrahydrocannabinol on the brain of young adults ( Cabeen et al, 2020 ), a study of diffuse axonal injury ( Ware et al, 2017 ), an investigation of the relation between fructose intake and brain connectivity in children ( Clark et al, 2020 ), a study on the effects of perivascular spaces on water diffusion in white matter ( Sepehrband et al, 2019 ), and studies that generated atlases of brainstem nuclei in IIT space ( Singh et al, 2019 ) ( Garcia-Gomar et al, 2019 ). The HARDI template of the atlas, which served as the foundation for the tractogram developed in the present work, was recently used to perform whole brain tractography in studies of depression ( Avecillas-Chasin et al, 2019 ), white matter maturation from infancy to adolescence ( Lynch et al, 2020 ), and Parkinson’s disease progression ( Yau et al, 2018 ).…”

Mapping the human subcortical auditory system using histology, postmortem MRI and in vivo MRI at 7T

“…A possible reason for this is the reduced signal- and contrast-to-noise ratio in these regions. Only very recently has 7T MRI enabled anatomical localization at the level of the SOC in individual subjects (García-Gomar et al, 2019). It should be noted that we could identify the SOC in the MNI ICBM 152 dataset that results from the average of a much larger cohort.…”