Search results for " mr"
showing 10 items of 495 documents
Medullary infarcts may cause ipsilateral masseter reflex abnormalities.
2007
There is a suprasegmental influence on the masseter reflex (MassR) in animals, which is mediated via the fifth nerve spinal nucleus (5SpN). Corresponding data in humans are lacking. Out of 268 prospectively recruited patients with clinical signs of acute brainstem infarctions, we identified 38 with magnetic resonance imaging (MRI)-documented unilateral infarcts caudal to the levels of the fifth nerve motor and main sensory nuclei. All had biplanar T2- and echo planar diffusion-weighted MRI and MassR testing. Five patients (13%) had ipsilateral MassR abnormalities. In all, the infarcts involved the region of the 5SpN. Patients with medullary infarcts involving the region of the 5SpN may thus…
Hidden sources of joy, fear, and sadness: Explicit versus implicit neural processing of musical emotions.
2016
Music is often used to regulate emotions and mood. Typically, music conveys and induces emotions even when one does not attend to them. Studies on the neural substrates of musical emotions have, however, only examined brain activity when subjects have focused on the emotional content of the music. Here we address with functional magnetic resonance imaging (fMRI) the neural processing of happy, sad, and fearful music with a paradigm in which 56 subjects were instructed to either classify the emotions (explicit condition) or pay attention to the number of instruments playing (implicit condition) in 4-s music clips. In the implicit vs. explicit condition, stimuli activated bilaterally the infe…
Gaming is related to enhanced working memory performance and task-related cortical activity
2017
Gaming experience has been suggested to lead to performance enhancements in a wide variety of working memory tasks. Previous studies have, however, mostly focused on adult expert gamers and have not included measurements of both behavioral performance and brain activity. In the current study, 167 adolescents and young adults (aged 13–24 years) with different amounts of gaming experience performed an n-back working memory task with vowels, with the sensory modality of the vowel stream switching between audition and vision at random intervals. We studied the relationship between self-reported daily gaming activity, working memory (n-back) task performance and related brain activity measured u…
Dynamic contrast-enhanced MRI parameters as biomarkers for the effect of vatalanib in patients with non-small-cell lung cancer.
2014
ABSTRACT: Aims: To assess the utility of dynamic contrast-enhanced MRI parameters in the demonstration of early antiangiogenic effects and as prognostic biomarkers in second-line treatment of advanced-stage non-small-cell lung cancer with vatalanib. Patients & methods: The transfer constant (Ktrans) and the initial area under the contrast concentration–time curve at 60 s (AUC60) were assessed in 46 patients. Changes were compared with response evaluation from computed tomography imaging and Response Evaluation Criteria In Solid Tumors guidelines. Results: Statistically significant mean reductions in Ktrans (38.4%; p < 0.0001) and AUC60 (24.9%; p < 0.0001) were found at day 2. Af…
Knockout of the KH-Type Splicing Regulatory Protein Drives Glomerulonephritis in MRL-Faslpr Mice
2021
KH-type splicing regulatory protein (KSRP) is an RNA-binding protein that promotes mRNA decay and thereby negatively regulates cytokine expression at the post-transcriptional level. Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by dysregulated cytokine expression causing multiple organ manifestations
Diagnosis of sclerosing cholangitis in children: blinded, comparative study of magnetic resonance versus endoscopic cholangiography.
2013
Summary Background Magnetic resonance cholangiography (MRC) has been validated as comparable to endoscopic retrograde cholangiography (ERC) for the diagnosis of sclerosing cholangitis (SC) in adult patients. In children, MRC is widely used based mainly on non-comparative studies. Patients and methods ERCs and MRCs of seven children (median age 9, range: 7–20 years) with SC and 17 controls (median age 6, range: 2 months–20 years) with other chronic liver diseases were reviewed in a blinded, random and independent way. All patients underwent both examinations within a 6-months slot. All ERCs and 17 MRCs were performed under general anesthesia. One radiologist evaluated both ERCs and MRCs and …
Intravoxel incoherent motion diffusion-weighted imaging in nonalcoholic fatty liver disease: a 3.0-T MR study.
2012
International audience; PURPOSE: To compare pure molecular diffusion, D, perfusion-related diffusion, D*, and perfusion fraction, f, determined from diffusion-weighted (DW) magnetic resonance (MR) imaging on the basis of the intravoxel incoherent motion (IVIM) theory in patients with type 2 diabetes with and without liver steatosis. MATERIALS AND METHODS: This prospective study was approved by the appropriate ethics committee, and written informed consent was obtained from all patients. Between December 2009 and September 2011, 108 patients with type 2 diabetes (51 men, 57 women; mean age, 50 years) underwent 3.0-T single-voxel point-resolved proton MR spectroscopy of the liver (segment VII…
Increased hippocampal head diffusivity predicts impaired episodic memory performance in early Alzheimer's disease
2010
Recent neuroanatomical and functional neuroimaging studies indicate that the anterior part of the hippocampus, rather than the whole structure, may be specifically involved in episodic memory. In the present work, we examined whether anterior structural measurements are superior to other regional or global measurements in mapping functionally relevant degenerative alterations of the hippocampus in Alzheimer's disease (AD). Twenty patients with early AD (MMSE 25.7+/-1.7) and 18 healthy controls were studied using magnetic resonance and diffusion-tensor imaging. Using a regions-of-interest analysis, we obtained volumetric and diffusivity measures of the hippocampal head and body-tail-section …
Comparison of Diffusion MRI Acquisition Protocols for the In Vivo Characterization of the Mouse Spinal Cord: Variability Analysis and Application to …
2016
Diffusion-weighted Magnetic Resonance Imaging (dMRI) has relevant applications in the microstructural characterization of the spinal cord, especially in neurodegenerative diseases. Animal models have a pivotal role in the study of such diseases; however, in vivo spinal dMRI of small animals entails additional challenges that require a systematical investigation of acquisition parameters. The purpose of this study is to compare three acquisition protocols and identify the scanning parameters allowing a robust estimation of the main diffusion quantities and a good sensitivity to neurodegeneration in the mouse spinal cord. For all the protocols, the signal-to-noise and contrast-to noise ratios…
Alterations in striatal neuropeptide mRNA produced by repeated administration of L-DOPA, ropinirole or bromocriptine correlate with dyskinesia induct…
2002
Chronic administration of L-DOPA to MPTP-treated common marmosets induces marked dyskinesia while repeated administration of equivalent antiparkisonian doses of ropinirole and bromocriptine produces only mild involuntary movements. The occurrence of dyskinesia has been associated with an altered balance between the direct and indirect striatal output pathways. Using in situ hybridisation histochemistry, we now compare the effects of these drug treatments on striatal preproenkephalin-A (PPE-A) and adenosine A(2a) receptor mRNA expression as markers of the indirect pathway and striatal preprotachykinin (PPT) mRNA and preproenkephalin-B (PPE-B, prodynorphin) mRNA expression as markers of the d…