Search results for "imaging techniques"
showing 10 items of 178 documents
Increased liver stiffness is associated with mortality in HIV/HCV coinfected subjects: The French nationwide ANRS CO13 HEPAVIH cohort study
2019
Background The association between liver stiffness measurements (LSM) and mortality has not been fully described. In particular the effect of LSM on all-cause mortality taking sustained virological response (SVR) into account needs further study. Methods HIV/HCV participants in the French nation-wide, prospective, multicenter ANRS CO13 HEPAVIH cohort, with ≥1 LSM by FibroScan (FS) and a detectable HCV RNA when the first valid FS was performed were included. Cox proportional hazards models with delayed entry were performed to determine factors associated with all-cause mortality. LSM and SVR were considered as time dependent covariates. Results 1,062 patients were included from 2005 to 2015 …
Dynamics of serum-induced endothelial cell apoptosis in patients with myocardial infarction
2013
In patients with ST-segment elevation myocardial infarction (STEMI) reperfused with primary coronary intervention (PCI), the dynamics of endothelial cell (EC) viability, apoptosis and necrosis and its relationship with the structural consequences on the left ventricle have not been addressed so far.In 20 STEMI patients, we incubated human umbilical vein endothelial cells (HUVECs) with serum drawn before reperfusion and subsequently afterwards (24, 96 h, 30 days). Viability, apoptosis and necrosis percentages were evaluated by flow cytometry. Values were compared with 12 age- and sex-matched control subjects with normal coronary arteries. Cardiac magnetic resonance (CMR) was performed during…
"I Know that You Know that I Know": Neural Substrates Associated with Social Cognition Deficits in DM1 Patients.
2016
Myotonic dystrophy type-1 (DM1) is a genetic multi-systemic disorder involving several organs including the brain. Despite the heterogeneity of this condition, some patients with non-congenital DM1 can present with minimal cognitive impairment on formal testing but with severe difficulties in daily-living activities including social interactions. One explanation for this paradoxical mismatch can be found in patients' dysfunctional social cognition, which can be assessed in the framework of the Theory of Mind (ToM). We hypothesize here that specific disease driven abnormalities in DM1 brains may result in ToM impairments. We recruited 20 DM1 patients who underwent the "Reading the Mind in th…
Outcomes of Surgery in Patients with Lumbar Spinal Canal Stenosis: Comparison of Three Types of Stenosis on MRI.
2016
The aim of the study was to compare outcome of surgery in patients with lumbar canal stenosis (LCS) based on magnetic resonance imaging (MRI) morphology. This was a prospective study of 96 consecutive patients who underwent surgery at 143 levels of LCS (from L3-L4 to L5-S1). Using patterns on T2 axial MRI, the type of stenosis was determined for each patient. The Swiss Spinal Stenosis Score (SSS) was used to evaluate patients’ functionality and outcomes. The definition of treatment success was based on the criteria developed by Stucki et al. Demographic characteristics and post-operative outcomes were compared between trefoil, triangular, and pin-hole groups. Finally, correlation between SS…
Quantification of intramuscular fat in patients with late-onset Pompe disease by conventional magnetic resonance imaging for the long-term follow-up …
2018
Objective The objective of this study was to evaluate a quantitative method based on conventional T1-weighted magnetic resonance (MR) imaging to assess fatty muscular degeneration in patients with late-onset Pompe disease and to compare it with semi-quantitative visual evaluation (the Mercuri score). In addition, a long-term retrospective data analysis was performed to evaluate treatment response to enzyme replacement therapy with alglucosidase alfa. Methods MR images of the lumbar spine were acquired in 41 patients diagnosed with late-onset Pompe disease from 2006 through 2015. Two independent readers retrospectively evaluated fatty degeneration of the psoas and paraspinal muscles by apply…
Automatic classification of tissues on pelvic MRI based on relaxation times and support vector machine
2019
International audience; Tissue segmentation and classification in MRI is a challenging task due to a lack of signal intensity standardization. MRI signal is dependent on the acquisition protocol, the coil profile, the scanner type, etc. While we can compute quantitative physical tissue properties independent of the hardware and the sequence parameters, it is still difficult to leverage these physical properties to segment and classify pelvic tissues. The proposed method integrates quantitative MRI values (T1 and T2 relaxation times and pure synthetic weighted images) and machine learning (Support Vector Machine (SVM)) to segment and classify tissues in the pelvic region, i.e.: fat, muscle, …
A co-registration investigation of inter-word spacing and parafoveal preview: Eye movements and fixation-related potentials
2019
Participants’ eye movements (EMs) and EEG signal were simultaneously recorded to examine foveal and parafoveal processing during sentence reading. All the words in the sentence were manipulated for inter-word spacing (intact spaces vs. spaces replaced by a random letter) and parafoveal preview (identical preview vs. random letter string preview). We observed disruption for unspaced text and invalid preview conditions in both EMs and fixation-related potentials (FRPs). Unspaced and invalid preview conditions received longer reading times than spaced and valid preview conditions. In addition, the FRP data showed that unspaced previews disrupted reading in earlier time windows of analysis, com…
Supplementing sleep actigraphy with button pressing while awake
2020
Objective/backgroundWrist-worn sleep actigraphs are limited for evaluating sleep, especially in sleepers who lie awake in bed without moving for extended periods. Sleep logs depend on the accuracy of perceiving and remembering times of being awake. Here we evaluated pressing an event-marker button while lying awake under two conditions: self-initiated pressing every 5 to 10 minutes or pressing when signaled every 5 minutes by a vibration pulse from a wristband. We evaluated the two conditions for acceptability and their concordance with actigraphically scored sleep.Participants and methodsTwenty-nine adults wore actigraphs on six nights. On nights 1 and 4, they pressed the marker to a vibra…
Aortic Function's Adaptation in Response to Exercise-Induced Stress Assessing by 1.5T MRI : A Pilot Study in Healthy Volunteers
2015
AIM:Evaluation of the aortic "elastic reserve" might be a relevant marker to assess the risk of aortic event. Our aim was to compare regional aortic elasticity at rest and during supine bicycle exercise at 1.5 T MRI in healthy individuals. METHODS:Fifteen volunteers (8 men), with a mean age of 29 (23-41) years, completed the entire protocol. Images were acquired immediately following maximal exercise. Retrospective cine sequences were acquired to assess compliance, distensibility, maximum rates of systolic distension and diastolic recoil at four different locations: ascending aorta, proximal descending aorta, distal descending aorta and aorta above the coeliac trunk level. Segmental aortic …
Fractionating auditory priors: A neural dissociation between active and passive experience of musical sounds
2019
Learning, attention and action play a crucial role in determining how stimulus predictions are formed, stored, and updated. Years-long experience with the specific repertoires of sounds of one or more musical styles is what characterizes professional musicians. Here we contrasted active experience with sounds, namely long-lasting motor practice, theoretical study and engaged listening to the acoustic features characterizing a musical style of choice in professional musicians with mainly passive experience of sounds in laypersons. We hypothesized that long-term active experience of sounds would influence the neural predictions of the stylistic features in professional musicians in a distinct…