Search results for "image processing"
showing 10 items of 3285 documents
Reconstruction of critical-size mandibular defects in immunoincompetent rats with human adipose-derived stromal cells
2013
In patients with bony defects, autologous bone grafts are the "gold standard" for reconstruction. In children, autologous bone harvesting is limited but tissue engineering offers an alternative. Next to bone marrow, adipose tissue is a source of mesenchymal stromal cells, and adipose-derived stromal cells (ADSC) can differentiate into osteocytes. The aim of this study was to evaluate the efficacy of bioactive implants (ADSC in fibrin glue) for repair of critical-size mandibular defects in athymic rats. Human adult ADSC embedded in fibrin glue were implanted into a critical-size defect in the rat mandible and their efficacy was compared to those of protected bone healing (pbh), autologous bo…
Diffusion-weighted MRI of the lung with hyperpolarized helium-3: A study of reproducibility
2005
Purpose To determine the reproducibility of several parameters of the ADC measurement by calculating the scan-to-scan intrasubject variability. Materials and Methods Measurements were performed using a gradient-echo sequence with a bipolar gradient for diffusion weighting (b = 3.89 sec/cm2). Five patients with pulmonary emphysema, and six healthy-lung volunteers were included in the study. Images were acquired after inspiration of 3He during a single inspiratory breath-hold. To assess the reproducibility, the measurement was performed twice (time between measurements = 20 minutes) without repositioning the subjects. Analysis was performed on the basis of region-of-interest (ROI) analysis an…
PERIODONTAL MICROCIRCULATORY ABNORMALITIES IN PATIENTS WITH SYSTEMIC SCLEROSIS
2005
BACKGROUND: The aim of this study was to observe the differences in periodontal microcirculation between healthy patients and patients with systemic sclerosis (SSc). METHODS: Fifteen healthy patients and 15 patients with SSc were examined. Periodontal capillaroscopy was used to investigate the characteristics of microcirculation. The visibility, course, tortuosity, possible presence of microhemorrhages, average caliber of the capillary loops, and number of visible capillary loops per square millimeter were evaluated for each patient. RESULTS: The investigation was simple, non-invasive, and repeatable for each patient. In patients with SSc, it was possible to observe a reduced number of capi…
Straight gyrus morphology in first-episode schizophrenia-spectrum patients
2010
et al.
Emotional words induce enhanced brain activity in schizophrenic patients with auditory hallucinations.
2005
Neuroimaging studies of emotional response in schizophrenia have mainly used visual (faces) paradigms and shown globally reduced brain activity. None of these studies have used an auditory paradigm. Our principal aim is to evaluate the emotional response of patients with schizophrenia to neutral and emotional words. An auditory emotional paradigm based on the most frequent words heard by psychotic patients with auditory hallucinations was designed. This paradigm was applied to evaluate cerebral activation with functional magnetic resonance imaging (fMRI) in 11 patients with schizophrenia with persistent hallucinations and 10 healthy subjects. We found a clear enhanced activity of the fronta…
Motor abnormalities and basal ganglia in first-episode psychosis (FEP)
2020
AbstractBackgroundMotor abnormalities (MAs) are the primary manifestations of schizophrenia. However, the extent to which MAs are related to alterations of subcortical structures remains understudied.MethodsWe aimed to investigate the associations of MAs and basal ganglia abnormalities in first-episode psychosis (FEP) and healthy controls. Magnetic resonance imaging was performed on 48 right-handed FEP and 23 age-, gender-, handedness-, and educational attainment-matched controls, to obtain basal ganglia shape analysis, diffusion tensor imaging techniques (fractional anisotropy and mean diffusivity), and relaxometry (R2*) to estimate iron load. A comprehensive motor battery was applied incl…
Non-compact myocardium assessment by cardiac magnetic resonance: dependence on image analysis method
2018
To compare image analysis methods for the assessment of left ventricle non-compaction from cardiac magnetic resonance (CMR) imaging. CMR images were analyzed in 20 patients and 10 normal subjects. A reference model of the MR signal was introduced and validated based on image data. Non-compact (NC) myocardium size and distribution were assessed by tracing a single, continuous contour delimiting trabeculated region (Jacquier) or by one-by-one selection of trabeculae (Grothoff). The global non-compact/compact (NC/C) ratio, the NC mass, and the segmental NC/C ratio were assessed. Results were compared with the reference model. A significant difference between Grothoff and Jacquier approaches in…
TC perfusionale nell'ischemia cerebrale acuta: Valore predittivo dei parametri di perfusione cerebrale nel discriminare il tessuto vitale da quello i…
2007
Purpose. The aim of this study was to assess the value of computed tomography (CT) perfusion parameters in differentiating tissue viability in acute stoke patients. Materials and methods. Thirteen patients (mean age 63.3 years) with nonhaemorrhagic stroke underwent multidetector perfusion CT within 3 h of symptom onset. Images were continuously acquired at the basal ganglia over 40 s during injection of 90 ml of iodinated contrast medium injected at a rate of 9 ml/s with a 9-s delay. Z-axis coverage was 20 mm. All patients underwent diffusion-weighted magnetic resonance imaging (DWI) within 12 h of perfusion CT to define the extent of the infarct. Perfusion CT data were analysed in regions …
Maternal history of reading difficulty is associated with reduced language-related gray matter in beginning readers.
2012
Family history and poor preliteracy skills (referred to here as familial and behavioral risk, respectively) are critical predictors of developmental dyslexia. This study systematically investigated the independent contribution of familial and behavioral risks on brain structures, which had not been explored in past studies. We also examined the differential effects of maternal versus paternal history on brain morphometry, and familial risk dimensionally versus categorically, which were also novel aspects of the study. We assessed 51 children (5 to 6 years of age) with varying degrees of familial and behavioral risks for developmental dyslexia and examined associations with brain morphometry…
Reproducibility of digital image analysis for measuring corneal haze after myopic photorefractive keratectomy.
1997
Purpose To evaluate the usefulness of digital image analysis for quantifying corneal haze by determining the reproducibility of its measurements at the corneal plane. Methods In a prospective study, 20 randomly selected eyes that had undergone myopic photorefractive keratectomy were photographed focusing the slit beam on their anterior corneal surface. Each photograph was examined using computer image analysis techniques that detect the edge of the reticular pattern of the image. Quantification of the difference between two areas, treated and adjacent untreated cornea, each containing 3,750 pixels with a resolution of 256 gray levels, was performed. Intra-analyzer variation was determined b…