Search results for "ULTRASOUND"
showing 10 items of 1259 documents
PERIPHERAL SURFACE DOSE FROM A LINEAR ACCELERATOR: RADIOCHROMIC FILM EXPERIMENTAL MEASUREMENTS OF FLATTENING FILTER FREE VERSUS FLATTENED BEAMS
2020
Abstract There is a growing interest in the use of flattening filter free (FFF) beams due to the shorter treatment times. The reduction of head scatter suggests a better radiation protection to radiotherapy patients, considering the expected decrease in peripheral surface dose (PSD). In this work, PSD of flattened (FF) and FFF-photon beams was compared. A radiochromic film calibration method to reduce energy dependence was used. PSD was measured at distances from 2 to 50 cm to the field border for different square field sizes, modifying relevant clinical parameters. Also, clinical breast and prostate stereotactic body radiotherapy (SBRT) plans were studied. For square beams, FFF PSD is lowe…
Peroperative Intravascular Ultrasound for Endovascular Aneurysm Repair versus Peroperative Angiography: A Pilot Study in Fit Patients with Favorable …
2020
The aim of this study was to compare intravascular ultrasound (IVUS) assistance for endovascular aortic aneurysm repair (EVAR) to standard assistance by angiography.From June 2015 to June 2017, 173 consecutive patients underwent EVAR. In this group, 69 procedures were IVUS-assisted with X-ray exposure limited to completion angiography for safety purposes because an IVUS probe does not yet incorporate a duplex probe (group A), and 104 were angiography-assisted procedures (group B). All IVUS-assisted procedures were performed by vascular surgeons with basic duplex ultrasound (DUS) training. The primary study endpoints were mean radiation dose, duration of fluoroscopy, amount of contrast media…
Single-centre experience and preliminary Results of intravascular ultrasound in endovascular aneurysm repair
2019
Background Intravascular ultrasound (IVUS) has been introduced as diagnostic adjunct to provide new insights into the diagnosis and therapy of vascular disease. Herein, we compared the outcomes of conventional endovascular aneurysm repair (EVAR) and EVAR with IVUS in patients presenting with infrarenal abdominal aortic aneurysm using a propensity-matched cohort. Methods From May 2013 to August 2017, 221 patients were retrospectively analyzed. Of that, 122 patients were eligible for inclusion and underwent propensity score matching. Perioperative mortality and morbidity, renal function impairment, endoleak incidence, mean contrast medium usage, operative time, radiation exposure (including f…
The effect of chronic low-dose environmental radiation on organ mass of bank voles in the Chernobyl Exclusion Zone
2020
Purpose: Animals are exposed to environmental ionizing radiation (IR) externally through proximity to contaminated soil and internally through ingestion and inhalation of radionuclides. Internal organs can respond to radioactive contamination through physiological stress. Chronic stress can compromise the size of physiologically active organs, but studies on wild mammal populations are scarce. The effects of environmental IR contamination on organ masses was studied by using a wild rodent inhabiting the Chernobyl Exclusion Zone (CEZ). Material and Methods: The masses of brain, heart, kidney, spleen, liver and lung were assessed from bank voles (Myodes glareolus) captured from areas across r…
Diagnostic Value of Optical Spectral Transmission in Rheumatoid Arthritis: Associations with Clinical Characteristics and Comparison with Joint Ultra…
2020
Objective.To examine the value of optical spectral transmission (OST) in detecting joint inflammation in patients with rheumatoid arthritis (RA) and to evaluate whether OST correlates with certain patient characteristics.Methods.OST measurements were performed in the metacarpophalangeal, proximal intraphalangeal, and wrist joints of 168 patients with RA and 114 controls. OST difference between the 2 groups was statistically examined and subsequently controlled for the effect of possible confounding factors. Diagnostic OST performance was tested by receiver-operating characteristics. Moreover, associations of OST with clinical and serological activity markers (patient group), joint ultrasoun…
ProstateAnalyzer: web-based medical application for the management of prostate cancer using multiparametric MR imaging
2016
Objectives: In this paper, we present ProstateAnalyzer, a new web-based medical tool for prostate cancer diagnosis. ProstateAnalyzer allows the visualization and analysis of magnetic resonance images (MRI) in a single framework. Methods: ProstateAnalyzer recovers the data from a PACS server and displays all the associated MRI images in the same framework, usually consisting of 3D T2-weighted imaging for anatomy, dynamic contrast-enhanced MRI for perfusion, diffusion-weighted imaging in the form of an apparent diffusion coefficient (ADC) map and MR Spectroscopy. ProstateAnalyzer allows annotating regions of interest in a sequence and propagates them to the others. Results: From a representat…
Children show hemispheric differences in the basic auditory response properties
2019
Auditory cortex in each hemisphere shows preference to sounds from the opposite hemifield in the auditory space. Besides this contralateral dominance, the auditory cortex shows functional and structural lateralization, presumably influencing the features of subsequent auditory processing. Children have been shown to differ from adults in the hemispheric balance of activation in higher-order auditory based tasks. We studied, first, whether the contralateral dominance can be detected in 7- to 8-year-old children and, second, whether the response properties of auditory cortex in children differ between hemispheres. Magnetoencephalography (MEG) responses to simple tones revealed adult-like cont…
Maturation changes the excitability and effective connectivity of the frontal lobe : A developmental TMS-EEG study
2019
The combination of transcranial magnetic stimulation with simultaneous electroencephalography (TMS–EEG) offers direct neurophysiological insight into excitability and connectivity within neural circuits. However, there have been few developmental TMS–EEG studies to date, and they all have focused on primary motor cortex stimulation. In the present study, we used navigated high‐density TMS–EEG to investigate the maturation of the superior frontal cortex (dorsal premotor cortex [PMd]), which is involved in a broad range of motor and cognitive functions known to develop with age. We demonstrated that reactivity to frontal cortex TMS decreases with development. We also showed that although fron…
Quality control of B-lines analysis in stress Echo 2020
2018
Background The effectiveness trial “Stress echo (SE) 2020” evaluates novel applications of SE in and beyond coronary artery disease. The core protocol also includes 4-site simplified scan of B-lines by lung ultrasound, useful to assess pulmonary congestion. Purpose To provide web-based upstream quality control and harmonization of B-lines reading criteria. Methods 60 readers (all previously accredited for regional wall motion, 53 B-lines naive) from 52 centers of 16 countries of SE 2020 network read a set of 20 lung ultrasound video-clips selected by the Pisa lab serving as reference standard, after taking an obligatory web-based learning 2-h module ( http://se2020.altervista.org ). Each te…
Improved contrast for myeloma focal lesions with T2-weighted Dixon images compared to T1-weighted images
2019
International audience; Purpose: The purpose of this study was twofold. First, to compare the contrast between spinal multiple myeloma (MM) focal lesions and surrounding bone marrow obtained on T2-weighted Dixon fat-only MR images to that obtained on T1-weighted spin-echo images. Second, to search for correlation between bone marrow fat fraction assessed by T2-weighted Dixon sequence and International Myeloma Working Group myeloma defining events.Materials and methods: A total of 39 patients with 112 focal MM lesions were included. There were 25 men and 14 women with a mean age of 68.8±9.8 [SD] years (range: 49-88 years). Contrast between focal MM lesions and surrounding bone marrow was cal…