The aim of this study was to demonstrate the advantages of patient dosimetry using voxel models and to present sets of dose estimates for patients of different gender and size. These models offer greater realism with respect to organ shape and topology than the well-established Medical Internal Radiation Dose (MIRD)-type mathematical models. At the National Research Centre for Environment and Health (GSF), specific absorbed fractions have been previously calculated for 4 male and 3 female voxel models, representing different age and stature, for a wide range of source organs. For this study, estimates both for established and new radiopharmaceuticals were performed using biokinetic data from International Commission on Radiological Protection (ICRP). The above calculations allowed for comparison to the MIRD technique in relation to the resulting absorbed organ and effective doses. Furthermore, data sets representing a range of voxel phantoms were investigated. It was found that dose differences among the voxel models can amount up to a factor of 3.
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http://dx.doi.org/10.1089/cbr.2005.20.103 | DOI Listing |
J Magn Reson Imaging
January 2025
Department of Neurology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
Background: Central arterial stiffening is associated with brain white matter (WM) damage and gray matter (GM) volume loss in older adults, but little is known about this association from an adult lifespan perspective.
Purpose: To investigate the associations of central arterial stiffness with WM microstructural organization, WM lesion load, cortical thickness, and GM volume in healthy adults across the lifespan.
Study Type: This is a cross-sectional study.
Alzheimers Res Ther
January 2025
Laboratory for Clinical Neuroscience, Center for Biomedical Technology, Universidad Politécnica de Madrid, IdISSC, Crta M40, km38, Madrid, 28223, Spain.
Background: Dementia patients commonly present multiple neuropathologies, worsening cognitive function, yet structural neuroimaging signatures of dementia have not been positioned in the context of combined pathology. In this study, we implemented an MRI voxel-based approach to explore combined and independent effects of dementia pathologies on grey and white matter structural changes.
Methods: In 91 amnestic dementia patients with post-mortem brain donation, grey matter density and white matter hyperintensity (WMH) burdens were obtained from pre-mortem MRI and analyzed in relation to Alzheimer's, vascular, Lewy body, TDP-43, and hippocampal sclerosis (HS) pathologies.
NMR Biomed
February 2025
MR Methodology, Department for Diagnostic and Interventional Neuroradiology, University of Bern, Bern, Switzerland.
The purpose of this study was to produce metabolite-specific T and concentration maps in a clinically compatible time frame. A multi-TE 2D MR spectroscopic imaging (MRSI) experiment (multi-echo single-shot MRSI [MESS-MRSI]) deployed truncated and partially sampled multi-echo trains from single scans and was combined with simultaneous multiparametric model fitting. It was tested in vivo for the brain in five healthy subjects.
View Article and Find Full Text PDFTrends Biotechnol
January 2025
State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310058, People's Republic of China; School of Mechanical Engineering, Zhejiang University, Hangzhou, 310058, People's Republic of China. Electronic address:
Replicating the contractile function of arterial tissues in vitro requires precise control of cell alignment within 3D structures, a challenge that existing bioprinting techniques struggle to meet. In this study, we introduce the voxel-based embedded construction for tailored orientational replication (VECTOR) method, a voxel-based approach that controls cellular orientation and collective behavior within bioprinted filaments. By fine-tuning voxel vector magnitude and using an omnidirectional printing trajectory, we achieve structural mimicry at both the macroscale and the cellular alignment level.
View Article and Find Full Text PDFAJNR Am J Neuroradiol
January 2025
Department of Neurosurgery and Neurooncology (M.M., A.B., T.M., D.K., D.N.), First Faculty of Medicine, Charles University and Military University Hospital, Prague, Czech Republic.
Background And Purpose: Diffuse gliomas, a heterogeneous group of primary brain tumors, have traditionally been stratified by histology, but recent insights into their molecular features, especially the mutation status, have fundamentally changed their classification and prognosis. Current diagnostic methods, still predominantly relying on invasive biopsy, necessitate the exploration of noninvasive imaging alternatives for glioma characterization.
Materials And Methods: In this prospective study, we investigated the utility of the spherical mean technique (SMT) in predicting the status and histologic grade of adult-type diffuse gliomas.
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