Search results for " Computer"
showing 10 items of 6910 documents
D2-receptor imaging with [123I]IBZM and Single Photon Emission Tomography in psychiatry: a survey of current status
1995
D2-dopamine receptors can be visualized in the human brain in vivo by Single Photon Emission Tomography (SPECT) and the radiolabeled benzamide [123I]IBZM. The present paper reviews the current status of this type of functional brain imaging with respect to basic methodological aspects, data analysis and quantification. The results from published clinical studies in different psychiatric patient populations and normal controls with [123I]IBZM are reviewed. [123I]IBZM-SPECT is a powerful tool for the investigation of D2-dopamine receptor status in psychiatric disorders, different types of drug treatment as well as therapeutic and side effects of pharmacologic agents. However, there still is a…
High Dynamic Range Spectral Imaging Pipeline For Multispectral Filter Array Cameras
2017
Spectral filter arrays imaging exhibits a strong similarity with color filter arrays. This permits us to embed this technology in practical vision systems with little adaptation of the existing solutions. In this communication, we define an imaging pipeline that permits high dynamic range (HDR)-spectral imaging, which is extended from color filter arrays. We propose an implementation of this pipeline on a prototype sensor and evaluate the quality of our implementation results on real data with objective metrics and visual examples. We demonstrate that we reduce noise, and, in particular we solve the problem of noise generated by the lack of energy balance. Data are provided to the community…
Hypertrophic cardiomyopathy and fibrosis: correlation between late gadolinium enhancement on CMR and speckle tracking imaging using Ultrasound
2015
Background Hypertrophic cardiomyopathy (HCM) is the most frequent genetic cardiovascular disorder and represents one of the most common cause of heart related sudden death in young adults. Myocardial fibrosis seems to be an independant predictor of adverse events including sudden death, ventricular arrhythmias and heart failure. While late gadolinium enhancement (LGE) on Cardiac Magnetic Resonance (CMR) is actually the gold-standard to detect fibrosis, new techniques are being evaluated such as 2D strain echocardiography.
Causal analysis of short-term cardiovascular variability: state-dependent contribution of feedback and feedforward mechanisms.
2016
Baroreflex function is usually assessed from spontaneous oscillations of blood pressure (BP) and cardiac RR interval assuming a unidirectional influence from BP to RR. However, the interaction of BP and RR is bidirectionalâRR also influences BP. Novel methods based on the concept of Granger causality were recently developed for separate analysis of feedback (baroreflex) and feedforward (mechanical) interactions between RR and BP. We aimed at assessing the proportion of the two causal directions of the interactions between RR and systolic BP (SBP) oscillations during various conditions, and at comparing causality measures from SBP to RR with baroreflex gain indexes. Arterial BP and ECG sig…
Cardiovascular magnetic resonance-derived aortic compliance, distensibility and pulse wave velocity at rest and during a supine bicycle exercise in y…
2014
Background Purpose: Risk of aortic rupture is evaluated based on the vessel diameter; this parameter is probably insufficient. In vivo evaluation of biomechanical property of the aortic tissue might be of interest to discriminate between normal and altered aortic tissue (A Lalande et al, JMRI 2008). The purpose of this study was to describe a technique to measure regional aortic compliance (AC), aortic distensibility (AD) and aortic stiffness with 1.5 T MRI in young individuals under resting conditions and during supine bicycle exercise.
Imaging of Ventriculoperitoneal Shunt Complications: Comparison of Whole Body Low-Dose Computed Tomography and Radiographic Shunt Series.
2016
OBJECTIVE To determine diagnostic value and radiation exposure of low-dose computed tomography (LD-CT) compared to radiographic shunt series (SS) for the detection of ventriculoperitoneal (VP) shunt complications. METHODS Fourteen VP shunts were implanted in 7 swine cadavers. Mechanical complications were induced in 50% of VP shunts. Low-dose CT (80 kVp, 10 mAs, Pitch = 1.5) and SS were acquired. Dose area product (DAP) and effective doses for SS and LD-CT were collected. Scoring of diagnostic confidence and blinded readings of SS and CT data were performed. RESULTS The sensitivity of LD-CT was high (0.97; 95% confidence interval, 0.91-1.00) with excellent interobserver agreement (κ = 0.88)…
Accuracy of automatic airway morphometry in computed tomography-correlation of radiological-pathological findings.
2010
Abstract Objectives Airway morphology shows characteristic changes in different pathologies. This study assesses the accuracy of a current automatic airway assessment technique by correlating CT images of porcine airways to histological slices of the same localization. Materials and methods Four isolated and ventilated porcine lungs were frozen in a liquid nitrogen bath and examined with a CT scanner (MDCT). This technique both preserved normal radiomorphological appearance and made it possible to slice the specimens for histological examination for subsequent correlation. The parameters wall thickness (WT), wall percentage (WP), and total diameter (TD) were assessed by computer-aided measu…
Towards EEG-Based Haptic Interaction within Virtual Environments
2019
International audience; Current virtual environments (VE) enable perceiving haptic stimuli to facilitate 3D user interaction, but lack brain-interfacial contents. Using electroencephalography (EEG), we undertook a feasibility study on exploring event-related potential (ERP) patterns of the user's brain responses during haptic interaction within a VE. The interaction was flying a virtual drone along a curved transmission line to detect defects under the stimuli (e.g., force increase and/or vibrotactile cues). We found that there were variations in the peak amplitudes and latencies (as ERP patterns) of the responses at about 200 ms post the onset of the stimuli. The largest negative peak occu…
Use of a Virtual Environment to Engage Motor and Postural Abilities in Elderly Subjects With and Without Mild Cognitive Impairment (MAAMI Project)
2016
Objectives: In the context of rehabilitation, the use of new technology such as Virtual Reality Technology (VRT) offers multiple possibilities to modulate the functional stimulation of subjects according to needs. Material and methods: In this study, the validity and reliability of our VRT system were investigated in fifteen healthy aged adults (HAA) and seven aged subjects with mild cognitive impairment (MCI). One implicit session was designed through two virtual environments (VEs) in order to induce the adapted activities associated with balance and postural control. In comparison, the same activities were achieved in explicit sessions with a physiotherapist. This cross-over study made us…
Use of telemedicine in inflammatory bowel disease: a real monitoring option?
2016
Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn’s disease (CD), is a chronic and relapsing disorder characterized by inflammation of the gastrointestinal tract. The natural progression includes periods of flares and remission, requiring continuous and personalized follow-up to achieve long remission and minimize short and long term damage. In fact, IBD patients show significantly higher rates of utilization of healthcare resources than patients with other conditions [1]. It is important to emphasize that 30-45% of adults are nonadherents [2], making these patients five times more likely to suffer relapses and consequently increasing health care costs [3]. …