Human brain and AI

The Pineal Gland (PG) is a part of the human brain epithalamus that plays an important role in sleep, circadian rhythm, immunity, and reproduction. PG parenchyma is composed mainly of pinealocytes secreting melatonin.
The formation of concrements in human pineal gland (PG) is a physiological process. However, according to many researchers, it is associated with the involution of PG structures. The calcium deposits in PG can interfere with normal function of the organ and can be associated with different health disorders I ncluding serious neurological diseases.

(a) Photographic image of the sagittal section of the human brain; (b) human PG; (c) micro-computed tomography (micro-CT) image of a calciﬁed human PG, dense-calciﬁed structures appear white, whereas low-density PG soft tissue is assigned dark color.

(d) X-ray phase contrast image (XPCT) image of pinealocytes visible as a green cell’s bodies with bright nuclei. (e) Histological image of the pinealocytes with processes surrounded by connective fibers, halocyanine staining

*(d) Large conglomerate of calcifications. (e) Tomographic slice of the conglomerate with a noticeable layered structure at the edges.*

XPCT imaging revealed high-resolution details of age-related PG alteration and noticeable degenerative change in both concrements and soft tissue of PGs with neuropathology. In particular, we observed a hollow core and separated layers as well as deep ragged cracks in PG concrements of Alzheimer’s disease and vascular dementia samples.

(a–c) VD group: (a) concrement with segregation of layers. The arrow indicates the internal links remaining after the segregation; (b) concrement with a hollow core. The arrow indicates characteristic irregularities on the surface of the concrement; (c) calciﬁed conglomerate traversed by a deep, jagged ﬁssure; (d–f) AD group: (d) concrements with segregation of layers and hollow core; (e) concrements with numerous large cracks; (f) zoom of a concrement with cracks. (a–d) SYRMEP ELETTRA experiment, voxel size 0.9 × 0.9 × 0.9 µm3; (e and f) PETRA III, DESY experiment, voxel 0.64 × 0.64 × 0.64 µm3

The mammalian olfactory bulb (OB) is a part of the forebrain involved in olfaction. It plays an essential role in the sense of smell. OB has a laminar structure.
XPCT offers sufficient resolution and contrast to identify single cells in large volumes of the brain. The numerous microanatomical structures detectable in XPCT image of the OB, however, greatly complicate the manual delineation of OB neuronal cell layers. To address the challenging problem of fully automated segmentation of XPCT images of human OB morphological layers convolutional neural networks (CNN) were used to segment XPCT image of native unstained human OB.

(a) Photographic image of the human brain with two olfactory bulbs (bilateral reddishcolored structures) and olfactory tract (violet-colored bilateral bundle of nerve fibers); (b) immunohistochemical staining with antibodies to neuron-specific β-III-tubulin in human OB section (axial plane) with multi-layered cellular architecture: glomerular layer (GL), external plexiform layer (EPL), mitral cell layer & internal plexiform layer (MCL (+IPL)), granule cell layer (GL), anterior olfactory nucleus (AON); (c,d) XPCT grayscale image of the OB slice, (c) axial plane, (d) sagittal plane.

Multi-Class Segmentation. (a) Grayscale image of the OB tomographic slice; (b) multiclass mask manually annotated to segment OB anatomical layers, each color corresponds to one OB layer with a specific neural structure; (c) CNN generated multiclass ROI masks (the U-Net model). The grayscale of each mask corresponds to a specific OB layer; (d) grayscale slice image of the OB with the boundary of the OB layers outlined in red with ground-truth mask (manual segmentation) and in blue with CNN generated mask (the U-Net model).

References
Bukreeva I, et al. Med Phys. 2023 Mar;50(3):1601-1613. doi: 10.1002/mp.16080. Epub 2022 Nov 26. PMID: 36309985.

Junemann O.et al.. Cell Tissue Res. 2023 Jun 24. doi: 10.1007/s00441-023-03800-7. Epub ahead of print. PMID: 37354235.

Junemann O, ey al.. J Gerontol A Biol Sci Med Sci. 2023 Mar 26:glad091. doi: 10.1093/gerona/glad091. Epub ahead of print. PMID: 36966358.

Bukreeva I, et al. Micromorphology of pineal gland calcification in age-related neurodegenerative diseases. Med Phys. 2023 Mar;50(3):1601-1613. doi: 10.1002/mp.16080. Epub 2022 Nov 26. PMID: 36309985.

Meshkov A.et al.Deep Learning-Based Segmentation of Post-Mortem Human’s Olfactory Bulb Structures in X-ray Phase-Contrast Tomography. Tomography. 2022 Jul 22;8(4):1854-1868. doi: 10.3390/tomography8040156. PMID: 35894021; PMCID: PMC9331385.

A. Smolin, et al., Proceedings Volume 13072, Sixteenth International Conference on Machine Vision (ICMV 2023); 1307209 (2024) https://doi.org/10.1117/12.3023398