Search results for "Computer-assisted"
showing 10 items of 1186 documents
18F-Florbetaben PET/CT to Assess Alzheimer's Disease: A new Analysis Method for Regional Amyloid Quantification.
2019
Background and purpose While AD can be definitively confirmed by postmortem histopathologic examination, in vivo imaging may improve the clinician's ability to identify AD at the earliest stage. The aim of the study was to test the performance of amyloid PET using new processing imaging algorithm for more precise diagnosis of AD. Methods Amyloid PET results using a new processing imaging algorithm (MRI-Less and AAL Atlas) were correlated with clinical, cognitive status, CSF analysis, and other imaging. The regional SUVR using the white matter of cerebellum as reference region and scores from clinical and cognitive tests were used to create ROC curves. Leave-one-out cross-validation was carr…
Impaired semantic processing during sentence reading in children with dyslexia: combined fMRI and ERP evidence
2008
Developmental dyslexia is a specific disorder of reading acquisition characterized by a phonological core deficit. Sentence reading is also impaired in dyslexic readers, but whether semantic processing deficits contribute is unclear. Combining spatially and temporally sensitive neuroimaging techniques to focus on semantic processing can provide a more comprehensive characterization of sentence reading in dyslexia. We recorded brain activity from 52 children (16 with dyslexia, 31 controls) with functional magnetic resonance imaging (fMRI) and event-related potentials (ERP) in two separate counterbalanced sessions. The children silently read and occasionally judged simple sentences with seman…
Influence of image reconstruction parameters on cardiovascular risk reclassification by Computed Tomography Coronary Artery Calcium Score
2018
Objective: To investigate the influence of different CT reconstruction parameters on coronary artery calcium scoring (CACS) values and reclassification of predicted cardiovascular (CV) risk. Methods: CACS was evaluated in 113 patients undergoing ECG-gated 64-slice CT. Reference CACS protocol included standard kernel filter (B35f) with slice thickness/increment of 3/1.5 mm, and field-of-view (FOV) of 150â180 mm. Influence of different image reconstruction algorithms (reconstructed slice thickness/increment 2.0/1.0â1.5/0.8â3.0/2.0â3.0/3.0 mm; slice kernel B30f-B45f; FOV 200â250 mm) on Agatston score was assessed by Bland-Altman plots and concordance correlation coefficient (CCC) ana…
Plaque levels of patients with fixed orthodontic appliances measured by digital plaque image analysis
2011
Introduction A digital plaque image analysis system was developed to objectively assess dental plaque formation and coverage in patients treated with fixed orthodontic appliances. Methods The technique was used to assess plaque levels of 52 patients undergoing treatment with fixed appliances in the Department of Orthodontics at Johannes Gutenberg University in Mainz, Germany. Results Plaque levels ranged from 5.1% to 85.3% of the analyzed tooth areas. About 37% of the patients had plaque levels over 50% of the dentition, but only 10% exhibited plaque levels below 15% of tooth coverage. The mean plaque coverage was 41.9% ± 18.8%. Plaque was mostly present along the gum line and around the or…
The Structure and Usage of Female and Male Mouse Ultrasonic Vocalizations Reveal only Minor Differences
2012
Ultrasonic vocalizations (USV) of mice are increasingly recognized as informative dependent variables in studies using mouse models of human diseases. While pup vocalizations primarily serve to re-establish contact with the mother, adult male ‘‘songs’’ were considered to be courtship signals. Alternatively, mouse USVs may generally function as territorial signals. To distinguish between these two hypotheses, we compared the structure and usage of adult male and female USVs in staged resident-intruder encounters. If calls function primarily as courtship signals, males should respond stronger than females, specifically when presented with a female intruder. Refuting this hypothesis, we found …
Cognitive reserve impacts on inter-individual variability in resting-state cerebral metabolism in normal aging
2012
There is a great deal of heterogeneity in the impact of aging on cognition and cerebral functioning. One potential factor contributing to individual differences among the elderly is the cognitive reserve, which designates the partial protection from the deleterious effects of aging that lifetime experience provides. Neuroimaging studies examining task-related activation in elderly people suggested that cognitive reserve takes the form of more efficient use of brain networks and/or greater ability to recruit alternative networks to compensate for age-related cerebral changes. In this exploratory multi-center study, we examined the relationships between cognitive reserve, as measured by educa…
Color-coded diffusion-tensor-imaging of posterior cingulate fiber tracts in mild cognitive impairment.
2005
Abstract Different processes like microvascular dysfunction, free radical toxicity, β-amyloid deposits, and Wallerian degeneration can cause functionally relevant disturbances of cerebral neuronal networks by myelin degeneration. Color-coded diffusion-tensor-imaging (ccDTI) allows the structural identification and quantification of myelinated fiber tracts. Particularly, posterior cingulate fiber tracts, which are regarded as important neuronal substrates of the network representing memory processing can be localized only imprecisely by conventional magnetic resonance imaging techniques. The posterior cingulate bundles were assessed by ccDTI in 17 patients with amnestic mild cognitive impair…
Effects of cuticle structure and crystalline wax coverage on the coloration in young and old males of Calopteryx splendens and Calopteryx virgo
2010
Male secondary sexual characters, such as color patterns, are often investigated at the macroscale level. However, micro- and nanoscale levels of morphological investigations may reveal functional features responsible for a particular coloration, thus providing more information, e.g., about the condition dependence of male sexual characters. The aim of this paper was to investigate cuticle color and its structure in males of two congeneric damselfly species, Calopteryx splendens and Calopteryx virgo, and reveal possible color changes with age. According to spectrometer measurements, C. splendens males were bluer and had a greater saturation of blue in their abdomen than C. virgo males, whic…
Resting state glucose utilization and the CERAD cognitive battery in patients with Alzheimer's disease
2004
The present study examined the cortical functional representation of neuropsychological domains in Alzheimer's disease (AD) using positron emission tomography (PET) and the neuropsychological assessment battery of the Consortium to Establish a Registry of Alzheimer's Disease (CERAD). Thirty patients with clinical probable AD and 10 elderly healthy controls underwent (18)FDG brain PET imaging during a resting state. Correlations between metabolic values and cognitive measures were determined using a region of interest analysis with NEUROSTAT (University of Michigan, USA) and a voxel-based analysis with SPM96 (Wellcome Department, London, UK). Specific correlations were seen between measures …
Optimal frame rate when there were stallion sperm motility evaluations and determinations for kinematic variables using CASA-Mot analysis in differen…
2020
This study was conducted to determine optimum image capture frame rates (FRO) when there was evaluation of different types of counting chambers used for CASA-Mot determinations of stallion sperm motility. Sperm VCL was determined at frame rates of 25-250 f/s in: 1) Spermtrack® (Spk) 10 and 20 chambers (drop displacement-type chambers 10 and 20 μm-deep respectively; and 2) ISAS®D4C10, ISAS®D4C20 (10 and 20 μm-deep respectively) and ISAS®D4C20 L (20 μm-deep) capillary loaded chambers. Values for different sperm kinematic variables were determined using each chamber at 250 f/s, which is the maximum frame rate that the software can be used for analyses. With evaluation of Spk chambers, there wa…