Objective: A fine structure of the corpus callosum (CC), consisting of radial lines, is seen in historical anatomical atlases as far back as that of Vicq d'Azyr (1786). This study examines a similar pattern observed in vivo using high-resolution MR images at 7 T.
Methods: 8 healthy subjects were examined with 7.0-T MRI. Anatomical images were collected with a gradient echo scan with 0.5-mm isotropic resolution, which were rated for visibility of the radial pattern. In addition, the second eigenvector of the diffusion tensor images was examined.
Results: The fine radial lines are detected not only in the sagittal view but also in the axial view of the in vivo MR images. From this, it is likely that these structures are two-dimensional ribbons. Interestingly, and confirming the structural nature of these stripes, the second eigenvector of the diffusion tensor imaging data shows an extremely similar pattern of oriented foliate structure. A similar modular structure involving transient septa has been observed previously in histological sections of human fetal CC.
Conclusion: The separate sets of data-the atlas of Klingler, anatomical images and second eigenvector images-all indicate a ribbon-like arrangement of the fibres in the CC. As such, they closely match the structures shown in the drawn atlases of as old as 1786. Advances in knowledge: This ribbon arrangement of fibres in the CC, previously unseen in CT or lower field MRI, can now be observed in vivo. This appears to match over two centuries of ex vivo observations.
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http://dx.doi.org/10.1259/bjr.20160906 | DOI Listing |
J Chem Phys
January 2025
Hylleraas Centre for Quantum Molecular Sciences, Department of Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway.
Traditionally, excitation energies in coupled-cluster (CC) theory have been calculated by solving the CC Jacobian eigenvalue equation. However, based on our recent work [Jørgensen et al., Sci.
View Article and Find Full Text PDFJ Chem Theory Comput
January 2025
Research Unit of Structural Chemistry & Computational Biophysics, Leibniz-Forschungsinstitut für Molekulare Pharmakologie, Berlin 13125, Germany.
Density functional theory (DFT) calculations have emerged as a powerful theoretical toolbox for interpreting and analyzing the experimental nuclear magnetic resonance (NMR) spectra of chemical compounds. While DFT has been extensively used and benchmarked for isotropic NMR observables, the evaluation of the full chemical shielding tensor, which is necessary for interpreting residual chemical shift anisotropy (RCSA), has received much less attention, despite its recent applications in the structural elucidation of organic molecules. In this study, we present a comprehensive benchmark of carbon shielding anisotropies based on coupled cluster reference tensors taken from the NS372 benchmark data set.
View Article and Find Full Text PDFPurpose: Defining a microscopic tumor infiltration boundary is critical to the success of radiation therapy. Currently, radiation oncologists use margins to geometrically expand the visible tumor for radiation treatment planning in soft tissue sarcomas (STS). Image-based models of tumor progression would be critical to personalize the treatment radiation field to the pattern of sarcoma spread.
View Article and Find Full Text PDFRadiol Cardiothorac Imaging
February 2025
From the Department of Magnetic Resonance Imaging, Radiology Imaging Center, Fuwai Hospital, National Center for Cardiovascular Diseases, State Key Laboratory of Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road No. 167, Xicheng District, Beijing 100037, China (Z.D., Y.T., G.Y., X.M., S.Y., J.W., X.X., K.Y., M.L., X.C., S.Z.); Clinical and Technical Support, Philips Healthcare, Beijing, China (P.S.); and Paul C. Lauterbur Research Center for Biomedical Imaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, SZ University Town, Shenzhen, China (K.Z., Y.Z.).
Purpose To explore the diffusion characteristics of hypertrophic cardiomyopathy (HCM) using in vivo cardiac diffusion-tensor imaging (cDTI) and to determine whether cDTI could help identify abnormal myocardium beyond cardiac MRI findings of fibrosis and hypertrophy. Materials and Methods In this prospective study conducted from April to August 2023, participants with HCM and healthy volunteers were enrolled for cardiac MRI evaluation, including cine, late gadolinium enhancement (LGE), T1 mapping, and cDT imaging, using a 3.0-T scanner.
View Article and Find Full Text PDFISA Trans
December 2024
Department of Electrical Engineering, POSTECH, Gyungbuk Pohang 37673, Republic of Korea. Electronic address:
This study investigates the H consensus problem for multi-agent systems under Markov switching topology by designing a dynamic output-feedback (DOF) controller. First, an invariant property is presented to address the Markov switching topology utilizing the eigenvalues and eigenvectors of the Laplacian matrix. Second, the eigenvalues of each Laplacian matrix are regarded as bounded uncertainties, representing the variations between the second smallest eigenvalue and the largest eigenvalue, removing the effect of variable eigenvalues.
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