This paper presents a new combinatorial approach to surface reconstruction with sharp features. Different from other postprocessing methods, the proposed method provides a systematic way to identify and reconstruct sharp features from unorganized sample points in one integrated reconstruction process. In addition, unlike other approximation methods, the reconstructed triangulated surface is guaranteed to pass through the original sample points. In this paper, the sample points in the sharp regions are defined as characteristic vertices (c-vertices), and their associated poles (c-poles) are used as a "sculptor" to extract triangles from a Delaunay structure for the sharp features. But, for smooth surface regions, an efficient region-growing scheme is used for triangle extraction and connection. Since only the c-poles associated with the sharp regions are used to participate in the Delaunay computation with the sample points, the proposed algorithm is adaptive in the sense that, given a sampled object with less sharp features, the triangulation becomes more efficient. To validate the proposed algorithm, some detailed illustrations are given. Experimental results show that it is robust and highly efficient.
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http://dx.doi.org/10.1109/TVCG.2006.2 | DOI Listing |
Radiography (Lond)
January 2025
Department of Radiology, Charité Universitätsmedizin Berlin, Berlin, Germany; Berlin Institute of Health, Berlin, Germany.
Background: Facial recognition technology in medical imaging, particularly with head scans, poses privacy risks due to identifiable facial features. This study evaluates the use of facial recognition software in identifying facial features from head CT scans and explores a defacing pipeline using TotalSegmentator to reduce re-identification risks while preserving data integrity for research.
Methods: 1404 high-quality renderings from the UCLH EIT Stroke dataset, both with and without defacing were analysed.
Epilepsia
January 2025
Epilepsy Unit, Hôpital Gui de Chauliac, Montpellier, France.
Contemporary studies report nonconvulsive status epilepticus (NCSE) in Creutzfeldt-Jakob disease (CJD), based on benzodiazepine (BZP)-responsive epileptiform discharges on the electroencephalogram (EEG), with the following false syllogism: (1) intravenous (IV) administration of BZPs usually suppress ictal activity in NCSE; (2) in CJD, periodic sharp wave complexes (PSWCs) are suppressed by IV BZPs; (3) therefore, these patients have NCSE. This is a simplistic and invalid conclusion, because authors of 20th-century science reports have clearly shown that IV BZPs, short-acting barbiturates, and drugs with no antiseizure effects, such as chloral hydrate and IV naloxone, suppress PSWCs, but patients fall asleep with no clinical improvement. In contrast, IV methylphenidate transiently improves both the EEG and clinical states.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Cornell University, Ithaca, NY, USA.
Background: Spatial disorientation is an early symptom of Alzheimer's disease (AD). The hippocampus creates a cognitive map, wherein cells form firing fields in specific locations within an environment, termed place cells. Critically, place cells remain stable across visits to an environment, but change their firing rate or field location in a different environment.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Cornell University, Ithaca, NY, USA.
Background: Alzheimer's disease (AD) manifests with early spatial memory impairment and is linked to the degeneration of hippocampal circuits. Hippocampal sharp wave ripples (SWRs) are high-frequency population-burst events that coordinate the reactivation of neural assemblies (groups of neurons that become correlated in their firing patterns during learning) in post-learning sleep, which is the neural basis of memory consolidation. SWRs are reduced in the APP/PS1 mouse model of AD-like pathology.
View Article and Find Full Text PDFEur Radiol Exp
January 2025
Unit of Medical Physics, Pisa University Hospital "Azienda Ospedaliero-Universitaria Pisana", Pisa, Italy.
Background: Photon-counting detector (PCD) technology has the potential to reduce noise in computed tomography (CT). This study aimed to carry out a voxelwise noise characterization for a clinical PCD-CT scanner with a model-based iterative reconstruction algorithm (QIR).
Methods: Forty repeated axial acquisitions (tube voltage 120 kV, tube load 200 mAs, slice thickness 0.
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