Search results for "Computer-Assisted"
showing 10 items of 1186 documents
Assessment of the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level in patients with emphysema.
2006
Abstract Purpose To assess the relationship between lung parenchymal destruction and impaired pulmonary perfusion on a lobar level using CT and MRI in patients with emphysema. Material and methods Forty-five patients with severe emphysema (GOLD III and IV) underwent inspiratory 3D-HRCT and contrast-enhanced MR-perfusion (1.5T; 3.5 mm × 1.9 mm × 4 mm). 3D-HRCT data was analyzed using a software for detection and visualization of emphysema. Emphysema was categorized in four clusters with different volumes and presented as overlay on the CT. CT and lung perfusion were visually analyzed for three lobes on each side using a four-point-score to grade the abnormalities on CT (1: predominantly smal…
Influence of heart rate in the selection of the optimal reconstruction window in routine clinical multislice coronary angiography
2008
Purpose. The aim of our study was to assess the influence of heart rate on the selection of the optimal reconstruction window with 40-slice multidetector-row computed tomography (40-MDCT) coronary angiography. Materials and methods. We studied 170 patients (114 men, age 60 +/- 11.3 years) with suspected or known coronary artery disease with 40-MDCT coronary angiography. Patients [mean heart rate (HR) 62.9 +/- 9.3 bpm, range 42-94 bpm] were clustered in two groups (group A: HR <= 65 bpm; group B: HR >65 bpm). Multiphase reconstruction data sets were obtained with a retrospective electrocardiogram (ECG)-gated 40-MDCT coronary angiography scan from 0% to 95% every 5% of the R-R interval.…
Differences of airway dimensions between patients with and without bronchiolitis obliterans syndrome after lung transplantation-Computer-assisted qua…
2016
Abstract Background The aim of our retrospective study was to determine whether a dedicated software for assessment of airway morphology can detect differences in airway dimensions between patients with and without bronchiolitis obliterans syndrome (BOS), regarded as the clinical correlate of chronic lung allograft rejection. Methods 12 patients with and 14 patients without diagnosis of BOS were enrolled in the study. Evaluation of bronchial wall area percentage (WA%) and bronchial wall thickness (WT) in all follow-up CT scans was performed using a semiautomatic airway assessment tool. We assessed temporal changes (ΔWA%, ΔWT) and compared these morphological parameters with forced expirator…
Quantification of mitral valve stenosis by three-dimensional transesophageal echocardiography
1996
The aim of this study was the evaluation of the diagnostic potentials of transesophageal 3D- echocardiography in the determination of mitral valve stenosis. 54 patients were investigated by transthoracic and multiplane transesophageal echocardiography. In 41 patients cardiac catheterization was performed. 3D- echocardiographic data acquisition was performed by automatic transducer rotation at 2 degree increments over a span of 180 degrees. The transesophageal probe was linked to an ultrasound unit and to a 3D- workstation capable of ECG- and respiration gated data acquisition, postprocessing and 2D/3D image reconstruction. The mitral valve was visualized in sequential cross-sectional planes…
Gabor frames for classification of paroxysmal and persistent atrial fibrillation episodes
2016
[EN] In this study, we propose a new classification method for early differentiation of paroxysmal and persistent atrial fibrillation episodes, i.e. those which spontaneously or with external intervention will return to sinus rhythm within 7 days of onset from the ones where the arrhythmia is sustained for more than 7 days. Today, clinicians provide patients classification once the course of the arrhythmia has been disclosed. This classification problem is dealt with in this study. We study a sparse representation of surface electrocardiogram signals by means of Gabor frames and afterwards we apply a linear discriminant analysis. Thus, we provide an early discrimination, obtaining promising…
Modulation of [18F]fluorodopa (FDOPA) kinetics in the brain of healthy volunteers after acute haloperidol challenge.
2006
In animal studies, acute antipsychotic treatment was shown to enhance striatal DOPA-decarboxylase (DDC) activity. However, this phenomenon has not been demonstrated in humans by positron emission tomography (PET). Therefore, we investigated acute haloperidol effects on DDC activity in humans using [18F]fluorodopa (FDOPA) PET. Nine healthy volunteers were scanned with FDOPA in drug-free baseline conditions and after 3 days of haloperidol treatment (5 mg/day). A continuous performance test (CPT) was administered in both conditions. The net blood-brain clearance of FDOPA (K(in)app) in striatum, mesencephalon, and medial prefrontal cortex was calculated by volume-of-interest analysis. The macro…
Capsule Endoscopy versus Push Enteroscopy in Patients with Occult Gastrointestinal Bleeding
2003
Background Wireless capsule endoscopy is a new method enabling non-invasive diagnostic endoscopy of the entire small intestine. In this study we prospectively examined the diagnostic precision of capsule endoscopy compared with push enteroscopy in patients with occult gastrointestinal bleeding. Methods Between July 2001 and October 2002 we examined 48 patients with suspected disorders of the small intestine using capsule endoscopy. 33 patients with obscure bleeding (19 men, 14 women, mean age 58 +/- 23 years) were prospectively examined using capsule endoscopy and push enteroscopy. Results On average, the patients had been suffering from chronic gastrointestinal bleeding for 30 +/- 36 (1-12…
Age-related dermal collagen changes during development, maturation and ageing - a morphometric and comparative study.
2014
The tissue organisation of dermal collagen is gaining importance as a contributing factor both in development and ageing, as well as in skin maturation processes. In this work we aim to study different representative parameters of this structural organisation in 45 human skin samples of assorted ages, by means of image analysis. The variation of these parameters on the basis of age was assessed using several regression models (linear, quadratic and cubic). The area occupied by collagen was significantly reduced as a function of age in the papillary dermis (R(2) = 0.437, P < 0.0001), as well as the thickness of the collagen bundles (R(2) = 0.461, P < 0.0001), following statistical models of …
Identification of unknown dead bodies by X-ray image comparison of the skull using the X-ray simulation program FoXSIS.
2001
The aim of the study was to improve the objectivity of X-ray image comparison for the identification of unknown dead individuals. CT-data were collected for 30 macerated skulls. An already presented computer program which uses CT data to establish virtual X-ray images was used to obtain X-rays with different beam angulations simulating rotation, dorsal flexion, and ventral flexion. Specific parameters were measured on the simulated images. The frontal sinus reveals the highest variability not only between the individual skulls but also within an individual skull in different positions. The most consistent parameters with respect to different positions were the skull breadth, the biorbital b…
Role of high-resolution ultrasonography without and with real-time spatial compound imaging in evaluating the injured posterior cruciate ligament: pr…
2009
This study sought to compare high-resolution ultrasonography (HRUS) without and with compound imaging in evaluating the injured posterior cruciate ligament (PCL). Thirteen patients with a magnetic resonance imaging (MRI) diagnosis of PCL lesions (ten acute and three chronic) and 20 healthy controls underwent conventional and compound HRUS performed by the same radiologist who was blinded to the subjects' case-control status. The PCL was scanned in a longitudinal direction in all cases. HRUS images were assessed for PCL thickness by two other radiologists blinded to the number and type of PCL injury. PCLs were classified as normal or injured, and the latter as having acute or chronic injurie…