Search results for "Aging"

Non-invasive Spatial Mapping of Frequencies in Atrial Fibrillation: Correlation With Contact Mapping

2021

[EN] Introduction: Regional differences in activation rates may contribute to the electrical substrates that maintain atrial fibrillation (AF), and estimating them non-invasively may help guide ablation or select anti-arrhythmic medications. We tested whether non-invasive assessment of regional AF rate accurately represents intracardiac recordings. Methods: In 47 patients with AF (27 persistent, age 63 +/- 13 years) we performed 57-lead non-invasive Electrocardiographic Imaging (ECGI) in AF, simultaneously with 64-pole intracardiac signals of both atria. ECGI was reconstructed by Tikhonov regularization. We constructed personalized 3D AF rate distribution maps by Dominant Frequency (DF) ana…

Development of a Protocol for CCD Calibration: Application to a Multispectral Imaging System

2005

In this paper we describe in detail a method for calibrating a CCD-based camera. The calibration aims to remove both temporal and systematic noises introduced by the sensor, electronics, and optics after which we can correct the non-linearity of its response. For the non-linearity correction we use a simple and powerful approach consisting on a complementary approach between a polynomial fitting and an LUT based algorithm. The proposed methodology is accurate in the sense that it takes into account individual characteristics of each pixel. In each pixel, systematic noises are measured through acquiring offset images, thermal images, and FlatField images. A rigorous protocol for acquiring th…

Substantial Reduction of Platelet Adhesion by Heparin-Coated Stents

2001

Although optimized antiplatelet medication has improved the clinical outcome after coronary stenting, vessel occlusion and restenosis still remain a relevant clinical problem. Platelets play a key role in this process. Therefore, the authors compared the platelet adhesion on different stent surface modifications (electropolished without coating or coated with carbon, carbon and additional heparin, silicon carbide, or heparin alone) to investigate their role in reducing platelet adhesion. All stents and additional stainless steel plates were incubated in heparinized whole blood with radiolabeled platelets. After washing the stents and plates four times, radioactivity caused by the adhesion o…

Editorial: CBCT special issue

2014

In the dental community, it is a common belief that CBCT was invented for oral and maxillofacial imaging. Of course, we know that this is a myth since the technique of a volumetric CT is indeed much older and dates back to the late 1970s.1,2 Considering that CT was introduced in 1973, its volumetric counterpart was developed very soon thereafter driven by the need for high spatial and temporal resolution that a conventional CT at that time was not able to achieve. However, successful marketing of the technique indeed was much later, and certainly a consequence of the publication of “A new volumetric CT machine for dental imaging based on the cone-beam technique: preliminary results” by Mozz…

High Resolution CT Angiography in Detection of an Aneurysm of the Vein of Galen as a Source of Intracranial Haemorrhage in a Newborn.

2011

Cerebral haemorrhage is a rare condition in infants and carries a known poor prognosis. Common causes of spontaneous haemorrhage include various vascular venous lesions due to incomplete hydrovenous maturation, among them Galen vein aneurysm may be a very rare cause of cerebral haemorrhage. This report emphasizes the role of multidector CT with high resolution CT angiography in a newborn with cerebral hemorrhage caused by Galen vein aneurysm rupture. MDCT with high resolution CT angiography helps to differentiate the cause of haemorrhage, and to address the appropriate treatment.

Aging population and stroke: Red flag.

2020

Evaluation of atrial function by 2D strain echocardiography in patients with atrial fibrillation

2012

Abstract Objectives To evaluate atrial function by 2D strain in patients with atrial fibrillation (AF) and normal or slightly increased atrial size and to verify whether lower atrial strain is associated with more frequent AF recurrences. Materials and methods We studied 50 patients with AF, mean age 59.6 ± 13 years and 50 age-and gender-matched controls. We analyzed left atrial function through 2Dstrain imaging, after the re-establishment of sinus rhythm (SR) and we investigated about the recurrences of the arrhythmia. Results Atrial strain (AS) was lower in AF patients vs controls (LA p Conclusions The assessment of atrial function by strain imaging might help to identify patients who nee…

Practical recommendations for the application of DE 59/2013

2019

The changes introduced with Council Directive 2013/59/Euratom will require European Member States adapt their regulations, procedures and equipment to the new high standards of radiation safety. These new requirements will have an impact, in particular, on the radiology community (including medical physics experts) and on industry. Relevant changes include new definitions, a new dose limit for the eye lens, non-medical imaging exposures, procedures in asymptomatic individuals, the use and regular review of diagnostic reference levels (including interventional procedures), dosimetric information in imaging systems and its transfer to the examination report, new requirements on responsibiliti…

Cardiovascular Imaging Techniques in Systemic Rheumatic Diseases

2018

The risk of cardiovascular (CV) events and mortality is significantly higher in patients with systemic rheumatic diseases than in the general population. Although CV involvement in such patients is highly heterogeneous and may affect various structures of the heart, it can now be diagnosed earlier and promptly treated. Various types of assessments are employed for the evaluation of CV risk such as transthoracic or transesophageal echocardiography, magnetic resonance imaging (MRI), and computed tomography (CT) to investigate valve abnormalities, pericardial disease, and ventricular wall motion defects. The diameter of coronary arteries can be assessed using invasive quantitative coronarograp…

The role of PET radiomic features in prostate cancer: a systematic review

2021

Aim: This systematic review aims to present the available evidence on the use of radiomic features (RFs) extracted from PET imaging in patients with prostate cancer (PCa). Materials and methods: A comprehensive literature search of studies on the utility of PET-derived RFs in patients with PCa was performed in the PubMed/MEDLINE database through February 24th, 2021 using the following search string: [“positron-emission tomography” (MeSh terms) OR “positron emission tomography computed tomography” (MeSh terms) OR “positron-emission tomography” (all fields) OR “positron emission tomography computed tomography” (all fields) OR “PET” (all fields)] AND [“radiomics” (all fields) OR “radiomic” (al…