Search results for "contrast"
showing 10 items of 1162 documents
Subjective impressions do not mirror online reading effort: concurrent EEG-eyetracking evidence from the reading of books and digital media
2013
In the rapidly changing circumstances of our increasingly digital world, reading is also becoming an increasingly digital experience: electronic books (e-books) are now outselling print books in the United States and the United Kingdom. Nevertheless, many readers still view e-books as less readable than print books. The present study thus used combined EEG and eyetracking measures in order to test whether reading from digital media requires higher cognitive effort than reading conventional books. Young and elderly adults read short texts on three different reading devices: a paper page, an e-reader and a tablet computer and answered comprehension questions about them while their eye movemen…
Quadruple-Phase MDCT of the Liver in Patients with Suspected Hepatocellular Carcinoma: Effect of Contrast Material Flow Rate
2006
The purposes of this study were to evaluate the effect of contrast material flow rate (3 mL/sec vs 5 mL/sec) on the detection and visualization of hepatocellular carcinoma (HCC) with MDCT and the safety profile of iodixanol at different injection rates.In a prospective, randomized multicenter trial, 97 patients (83 men and 14 women, with a mean age of 64 years) suspected of having HCC underwent quadruple-phase (double arterial, portal venous, delayed phase) 4-16-MDCT. Patients were randomized to receive iodixanol, 320 mg I/mL (1.5 mL/kg body weight), at a flow rate of 3 mL/sec (48 patients) or 5 mL/sec (49 patients). Qualitative (lesion detection, image quality) and quantitative (liver and …
Contrast sensitivity after refractive lens exchange with a multifocal diffractive aspheric intraocular lens
2013
Purpose: To evaluate distance and near contrast sensitivity (CS) under photopic and mesopic conditions before and after refractive lens exchange (RLE) and implantation of the aspheric AcrySof ReSTOR (SN6AD3 model) intraocular lens (IOL) Methods: Sixty eyes of 30 consecutive patients after RLE underwent bilateral implantation with the aspheric AcrySof ReSTOR IOL. The patients sample was divided into myopic [n=15, mean spherical equivalent (SE) -6.87± 2.03 diopters (D)] and hyperopic (n=15, mean SE +4.52±1.14 D) groups. Monocular uncorrected visual acuity at distance and near (UCVA and UCNVA, respectively) and monocular best corrected visual acuity at distance and near (BCVA and BCNVA, respec…
Potential Use of a Diluted High-relaxivity Gadolinium-based Intra-articular Contrast Agent for Magnetic Resonance Arthrography: An In-vitro Study
2019
Abstract Background Magnetic resonance arthrography (MRA) requires intra-articular injection of gadolinium-based diluted paramagnetic contrast material. To our knowledge, gadobenate dimeglumine (Gd-BOPTA) has never been used for intra-articular applications. Our aim was to test in vitro different concentrations of Gd-BOPTA to be potentially used to perform MRA. Methods Gd-BOPTA was diluted in saline (NaCl 0.9%) to achieve different concentrations (4 mmol/l; 2 mmol/l; 1 mmol/l; 0.67 mmol/l; 0.5 mmol/l). Six sets of five sterile pipes were prepared with 5 ml of each solution, five sets added with 0.5 ml of fresh synovial fluid. Two separate pipes were prepared with 5 ml of gadopentetate dimeg…
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…
Incidence, Predictors, and Impact on Six-Month Mortality of Three Different Definitions of Contrast-Induced Acute Kidney Injury After Coronary Angiog…
2017
We assessed incidence, predictors, and impact on 6-month mortality of contrast-induced acute kidney injury (CI-AKI) after coronary angiography with or without percutaneous coronary intervention in patients with acute coronary syndrome (ACS), according to 3 different CI-AKI definitions. Serum creatinine (sCr) was assessed at baseline and 48 to 72 hours after procedure to classify patients into 3 CI-AKI groups: Group 1: increase in sCR ≥25% over baseline but absolute increase 25% in the remaining 844 (84.2%). CI-AKI was significantly associated with 6-month all-cause mortality using the definitions for Group 2 (hazard ratio 3.1, 95% confidence interval [CI] 1.5 to 6.6, p = 0.002) and Group 3 …
Differentiation of benign and malignant lymph nodes in pediatric patients on ferumoxytol-enhanced PET/MRI.
2019
The composition of lymph nodes in pediatric patients is different from that in adults. Most notably, normal lymph nodes in children contain less macrophages. Therefore, previously described biodistributions of iron oxide nanoparticles in benign and malignant lymph nodes of adult patients may not apply to children. The purpose of our study was to evaluate if the iron supplement ferumoxytol improves the differentiation of benign and malignant lymph nodes in pediatric cancer patients on 18F-FDG PET/MRI. Methods: We conducted a prospective clinical trial from May 2015 to December 2018 to investigate the value of ferumoxytol nanoparticles for staging of children with cancer with 18F-FDG PET/MRI.…
Vesicoureteral reflux in young patients: Comparison of voiding color Doppler US with echo enhancement versus voiding cystourethrography for diagnosis…
2004
We assessed the accuracy of voiding color Doppler ultrasonography (US) with echo enhancement for diagnosis or exclusion of vesicoureteral reflux (VUR) versus voiding cystourethrography (VCUG) and evaluated patient tolerance of the echo-enhancing agent. One hundred twenty-two patients (ages range, 1 month to 17 years) with 244 ureterorenal units underwent voiding color Doppler US with echo enhancement, which was followed by VCUG on the same day. After US of the urinary tract, the bladder was filled with saline solution via catheter. Then an echo-enhancing agent was instilled, and color Doppler US was performed. Reflux was diagnosed when microbubbles appeared in the ureter or the pelvicalicea…
Cognitive flexibility modulates maturation and music-training-related changes in neural sound discrimination
2015
Previous research has demonstrated that musicians show superior neural sound discrimination when compared to non-musicians, and that these changes emerge with accumulation of training. Our aim was to investigate whether individual differences in executive functions predict training-related changes in neural sound discrimination. We measured event-related potentials induced by sound changes coupled with tests for executive functions in musically trained and non-trained children aged 9-11 years and 13-15 years. High performance in a set-shifting task, indexing cognitive flexibility, was linked to enhanced maturation of neural sound discrimination in both musically trained and non-trained chil…
Contrast-induced Nephropathy after Percutaneous Coronary Intervention in Simple Lesions: Risk Factors and Incidence are Affected by the Definition Ut…
2011
Aim To compare the incidence, and risk factors, in-hospital and at the 18-month prognosis of contrast-induced nephropathy (CIN) according to the definition utilized: as an increase in serum creatinine (Scr) ≥0.5 mg/dL (CIN 1) or as an increase in Scr ≥25% above baseline values (CIN 2). Methods and Results We prospectively evaluated CIN according to two different definitions in 150 patients who underwent percutaneous coronary intervention (PCI) in simple lesions employing a low-medium dose of contrast media. Incidence of CIN was higher using the CIN 2 definition than CIN 1 (9.3% vs. 4%; p=0.0133). Patients with CIN 1 had a higher incidence of chronic kidney disease (CKD) (66.7% vs. 13.9%; p=…