Background: Deep learning (DL) often requires an image quality metric; however, widely used metrics are not designed for medical images.
Purpose: To develop an image quality metric that is specific to MRI using radiologists image rankings and DL models.
Study Type: Retrospective.
J Interv Card Electrophysiol
October 2024
Background: Achieving mitral isthmus (MI) block can be challenging. This prospective study evaluated the feasibility and efficacy of a systematic strategy comprising three consecutive steps to achieve MI block.
Methods: Twenty consecutive patients (mean (± SD) age 71.
Neurovascular 4D-Flow MRI enables non-invasive evaluation of cerebral hemodynamics including measures of cerebral blood flow (CBF), vessel pulsatility index (PI), and cerebral pulse wave velocity (PWV). 4D-Flow measures have been linked to various neurovascular disorders including small vessel disease and Alzheimer's disease; however, physiological and technical sources of variability are not well established. Here, we characterized sources of diurnal physiological and technical variability in cerebral hemodynamics using 4D-Flow in a retrospective study of cognitively unimpaired older adults (N = 750) and a prospective study of younger adults (N = 10).
View Article and Find Full Text PDFMagnetic resonance angiography sequences, such as time-of-flight and contrast-enhanced angiography, provide clear depiction of vessel lumen, traditionally used to evaluate carotid pathologic conditions such as stenosis, dissection, and occlusion; however, atherosclerotic plaques with a similar degree of stenosis may vary tremendously from a histopathological standpoint. MR vessel wall imaging is a promising noninvasive method to evaluate the content of the vessel wall at high spatial resolution. This is particularly interesting in the case of atherosclerosis as vessel wall imaging can identify higher risk, vulnerable plaques as well as has potential applications in the evaluation of other carotid pathologic conditions.
View Article and Find Full Text PDFObjective: Temporal lobe epilepsy (TLE) is characterized by recurrent seizures generated in the limbic system, particularly in the hippocampus. In TLE, recurrent mossy fiber sprouting from dentate gyrus granule cells (DGCs) crea an aberrant epileptogenic network between DGCs which operates via ectopically expressed GluK2/GluK5-containing kainate receptors (KARs). TLE patients are often resistant to anti-seizure medications and suffer significant comorbidities; hence, there is an urgent need for novel therapies.
View Article and Find Full Text PDFThere has been extensive growth in both the technical development and the clinical applications of MRI, establishing this modality as one of the most powerful diagnostic imaging tools. However, long examination and image interpretation times still limit the application of MRI, especially in emergent clinical settings. Rapid and abbreviated MRI protocols have been developed as alternatives to standard MRI, with reduced imaging times, and in some cases limited numbers of sequences, to more efficiently answer specific clinical questions.
View Article and Find Full Text PDFOften confused with pseudoclaudication, gluteal muscle claudication is a difficult condition to diagnose and treat. We present the case of a 67-year-old man with a history of back and buttock claudication. He had undergone lumbosacral decompression with no relief of buttock claudication.
View Article and Find Full Text PDFBackground Characterizing cerebrovascular hemodynamics in older adults is important for identifying disease and understanding normal neurovascular aging. Four-dimensional (4D) flow MRI allows for a comprehensive assessment of cerebral hemodynamics in a single acquisition. Purpose To establish reference intracranial blood flow and pulsatility index values in a large cross-sectional sample of middle-aged (45-65 years) and older (>65 years) adults and characterize the effect of age and sex on blood flow and pulsatility.
View Article and Find Full Text PDFAlzheimer's disease (AD) is the most common cause of dementia and is characterized by progressive neurodegeneration and cognitive decline. Understanding the pathophysiology underlying AD is paramount for the management of individuals at risk of and suffering from AD. The vascular hypothesis stipulates a relationship between cardiovascular disease and AD-related changes although the nature of this relationship remains unknown.
View Article and Find Full Text PDFBackground: Postoperative conduction disorders are serious adverse events in patients undergoing aortic valve replacement, and may prolong the duration of hospitalization and require pacemaker insertion.
Aim: Our aim was to evaluate the rate of pacemaker insertion after implantation of an Edwards Intuity sutureless aortic valve (Edwards Lifesciences, Irvine, CA, USA) compared with a standard surgical bioprosthesis.
Methods: This retrospective single-centre study included patients who underwent aortic valve replacement with an Intuity sutureless aortic valve or a standard bioprosthetic valve between 4 June 2014 and 27 June 2016.
Pacing Clin Electrophysiol
November 2022
Background: Transvenous pacemaker (PM) implantation is a complication in patients undergoing transcatheter aortic valve implantation (TAVI). Recently, a second generation of leadless PMs able of atrioventricular (AV) synchronous pacing has been introduced and could be an alternative when ventricular pacing is required after TAVI. Real-world data on Micra AV after TAVI are still lacking.
View Article and Find Full Text PDFThe dentate granule cells (DGCs) play a crucial role in learning and memory. Many studies have described the role and physiological properties of these sparsely active neurons using different behavioral contexts. However, the morpho-functional features of DGCs recruited in mice maintained in their home cage (without training), considered as a baseline condition, have not yet been established.
View Article and Find Full Text PDFJ Interv Card Electrophysiol
January 2022
Purpose: Diagnosis of atrial tachycardia (AT) with 3D mapping system remains challenging due to fibrosis or previous ablation. This study aims to evaluate a new electroanatomical mapping annotation setting using a window of interest adjusted at the end of the P wave (WOI) to identify the AT mechanism more accurately.
Methods: Twenty patients with successful ablation of left AT using navigation system CARTO3 were evaluated.
Purpose: Endovascular treatment of unruptured intracranial aneurysms with stent-assisted coiling or flow diverter stents requires a prophylactic antiplatelet premedication to avoid thrombo-embolic complications. Guidelines for optimal antiplatelet regimens are poorly defined. The aim of this study is to report our experience using a high dosage antiplatelet premedication regimen for patients with unruptured intracranial aneurysms undergoing endovascular treatment by stent-assisted coiling or flow diverter stents.
View Article and Find Full Text PDFObjective: Rewiring of excitatory glutamatergic neuronal circuits is a major abnormality in epilepsy. Besides the rewiring of excitatory circuits, an abnormal depolarizing γ-aminobutyric acidergic (GABAergic) drive has been hypothesized to participate in the epileptogenic processes. However, a remaining clinically relevant question is whether early post-status epilepticus (SE) evoked chloride dysregulation is important for the remodeling of aberrant glutamatergic neuronal circuits.
View Article and Find Full Text PDFThe trophic ecology of ichthyofauna in a stream can be related to the presence or absence of riparian and aquatic vegetation, and mainly resource availability. Therefore, the aim of this study was to analyse the seasonal and ontogenetic variations for the trophic ecology of Hemigrammus marginatus in the Beija-Flor stream located at the Jataí Ecological Station in the municipality of Luiz Antônio-SP, Brazil. In order to attain this objective, the data collections were carried out on a monthly basis from August, 2011 to July, 2012.
View Article and Find Full Text PDFMacrophytes may constitute an important resource for several chemical, physical and biological processes within aquatic ecosystems. This study considers that in tropical reservoirs with low retention time and with low values of shoreline development (DL), the expansion and persistence of aquatic macrophytes are mainly reported to local conditions (e.g.
View Article and Find Full Text PDFThe objective of the present study was to investigate the feeding habits allowing the occurrence of the congeneric species Stellifer rastrifer and Stellifer brasiensis, collected on a seasonal basis, in the operating area of the artisanal seabob-shrimp trawl fishery in Porto Belo, an important fishing area on the southern Brazilian coast. Fish were collected seasonally from November 2009 to August 2010, in isobaths of 10, 20 and 30 m. Of the 450 stomachs analyzed, 194 belonged to Stellifer rastrifer and 242 to Stellifer brasiliensis.
View Article and Find Full Text PDFObjective: Patients with temporal lobe epilepsy often display cognitive comorbidity with recurrent seizures. However, the cellular mechanisms underlying the impairment of neuronal information processing remain poorly understood in temporal lobe epilepsy. Within the hippocampal formation neuronal networks undergo major reorganization, including the sprouting of mossy fibers in the dentate gyrus; they establish aberrant recurrent synapses between dentate granule cells and operate via postsynaptic kainate receptors.
View Article and Find Full Text PDFGrowth and reproduction parameters of the yellow-mandi, Pimelodus maculatus Lacépède, 1803 (Siluriformes, Pimelodidae), were determined for the Cachoeira Dourada reservoir (GO/MG). The field work occurred throughout February 2007 to January 2008 (with the exception of December 2007). Gill nets with mesh sizes from 1.
View Article and Find Full Text PDFObjective: Subcortical band heterotopia (SBH) is a cortical malformation formed when neocortical neurons prematurely stop their migration in the white matter, forming a heterotopic band below the normotopic cortex, and is generally associated with intractable epilepsy. Although it is clear that the band heterotopia and the overlying cortex both contribute to creating an abnormal circuit prone to generate epileptic discharges, it is less understood which part of this circuitry is the most critical. Here, we sought to identify the origin of epileptiform activity in a targeted genetic model of SBH in rats.
View Article and Find Full Text PDFKainate is a potent neurotoxin known to induce acute seizures. However, whether kainate receptors (KARs) play any role in the pathophysiology of temporal lobe epilepsy (TLE) is not known. In TLE, recurrent mossy fiber (rMF) axons form abnormal excitatory synapses onto other dentate granule cells that operate via KARs.
View Article and Find Full Text PDFThe present study aimed to evaluate the interactions of the pesticide Vertimec(®) 18EC in aquatic ecosystems. In this respect, soil plots were contaminated with Vertimec(®) 18EC at the concentration indicated for strawberry crops (0.125L of solution m(-2)).
View Article and Find Full Text PDFThe limnological features and the phytoplankton community of the Cachoeira Dourada reservoir were analyzed in December 2006, May 2007 and November 2007. Temporal changes in the taxonomic composition, density, diversity and dominance of species were analyzed in relation to climatic factors and the physical and chemical characteristics of the water. A positive correlation was found between some of the physical and chemical variables and the phytoplankton community.
View Article and Find Full Text PDFDentate granule cells, at the gate of the hippocampus, use coincidence detection of synaptic inputs to code afferent information under a sparse firing regime. In both human patients and animal models of temporal lobe epilepsy, mossy fibers sprout to form an aberrant glutamatergic network between dentate granule cells. These new synapses operate via long-lasting kainate receptor-mediated events, which are not present in the naive condition.
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