1,721,019 research outputs found
Imaging Features of Non-Alcoholic Fatty Liver Disease in Children and Adolescents
No full textNon-invasive diagnosis and quantification of liver steatosis is important to overcome limits of liver biopsy, in order to follow up patients during their therapy and to establish a reference standard that can be used in clinical trials and longitudinal studies. Imaging offers several methods in this setting: ultrasound, which is the cheapest technique and easy to perform; magnetic resonance spectroscopy (MRS), which reflects the real content of triglycerides in a specific volume; and proton density fat fraction (PDFF) magnetic resonance, which is a simple method that reflects the distribution of the fat in the whole liver. Other techniques include ultrasound elastography (EUS) and magnetic resonance elastrography (MRE), which can evaluate the progression of non-alcoholic fatty liver disease (NAFLD) into non-alcoholic steato-hepatitis (NASH) and cirrhosis, by quantifying liver fibrosis
Comparison of magnetic resonance spectroscopy, proton density fat fraction and histological analysis in the quantification of liver steatosis in children and adolescents
Full text linkAIM:
To establish a threshold value for liver fat content between healthy children and those with non-alcoholic fatty liver disease (NAFLD) by using magnetic resonance imaging (MRI), with liver biopsy serving as a reference standard.
METHODS:
The study was approved by the local ethics committee, and written informed consent was obtained from all participants and their legal guardians before the study began. Twenty-seven children with NAFLD underwent liver biopsy to assess the presence of nonalcoholic steatohepatitis. The assessment of liver fat fraction was performed using MRI, with a high field magnet and 2D gradient-echo and multiple-echo T1-weighted sequence with low flip angle and single-voxel point-resolved 1H MR-Spectroscopy (1H-MRS), corrected for T1 and T2* decays. Receiver operating characteristic curve analysis was used to determine the best cut-off value. Lin coefficient test was used to evaluate the correlation between histology, MRS and MRI-PDFF. A Mann-Whitney U-test and multivariate analysis were performed to analyze the continuous variables.
RESULTS:
According to MRS, the threshold value between healthy children and those with NAFLD is 6%; using MRI-PDFF, a cut-off value of 3.5% is suggested. The Lin analysis revealed a good fit between the histology and MRS as well as MRI-PDFF.
CONCLUSION:
MRS is an accurate and precise method for detecting NAFLD in children
Diagnostic confidence of computed tomography and magnetic resonance in focal liver pathology.
No full textThe aim of this study was to evaluate and compare the diagnostic confidence of multiphase computed tomography (CT) and magnetic resonance (MR) after administration of gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) in the diagnosis of malignant-benign neoplasm of the liver in operators with different levels of experience.Forty patients underwent multiphase CT and MR after administration of Gd-EOB-DTPA. All exams were evaluated by two experienced observers independently; they rated their diagnostic confidence on a five-degree scale: 1 (certainly benign), 2 (probably benign), 3 (uncertain), 4 (probably malignant) and 5 (certainly malignant). Receiver operating characteristic curve analysis and area under the curve (AUC) were carried out for each observer and their difference was tested according to the different methodologies used.In our population, there were 15 malignant neoplasms and 25 benign neoplasms. For the CT analysis, AUC was 0.792 [SE=0.088; 95\% confidence interval (CI) 0.634-0.903] and 0.701 (SE=0.099; 95\% CI 0.535-0.835) for observers 1 and 2, respectively, whereas for the MR analysis, AUC was 0.923 (SE=0.058; 95\% CI 0.793-0.983) and 0.934 (SE=0.054; 95\% CI 0.808-0.987). For both observers, a statistically significant difference was found in diagnostic confidence between the AUC of CT and MR (P<0.05).Our results indicate that, for expert and intermediate experience observers, the diagnostic confidence using MR with Gd-EOB-DTPA is statistically significantly superior to CT with a multiphase technique
A double-blind, placebo-controlled randomized trial to evaluate the efficacy of docosahexaenoic acid supplementation on hepatic fat and associated cardiovascular risk factors in overweight children with nonalcoholic fatty liver disease
No full textAbstract Background and Aims: Very little information is available on whether docosahexaenoic
acid (DHA) supplementation has a beneficial effect on liver fat and cardiovascular disease (CVD)
risk factors in children with nonalcoholic fatty liver disease (NAFLD). In a double-blind, placebocontrolled
randomized trial we investigated whether 6-month treatment with DHA improves
hepatic fat and other fat depots, and their associated CVD risk factors in children with biopsyproven
NAFLD.
Methods and Results: Of 58 randomized children, 51 (25 DHA, 26 placebo) completed the study.
The main outcome was the change in hepatic fat fraction as estimated by magnetic resonance
imaging. Secondary outcomes were changes in visceral adipose tissue (VAT), epicardial adipose
tissue (EAT), and left ventricular (LV) function, as well as alanine aminotransferase (ALT), triglycerides,
body mass index-standard deviation score (BMI-SDS), and insulin sensitivity. At 6
months, the liver fat was reduced by 53.4% (95% CI, 33.4e73.4) in the DHA group, as compared
with 22.6% (6.2e39.0) in the placebo group (P Z 0.040 for the comparison between the two
groups). Likewise, in the DHA group VAT and EAT were reduced by 7.8% (0e18.3) and 14.2% (0
e28.2%), as compared with 2.2% (0e8.1) and 1.7% (0e6.8%) in the placebo group, respectively
(P Z 0.01 for both comparisons). There were no significant between-group changes for LV function
as well as BMI-SDS and ALT, while fasting insulin and triglycerides significantly decreased in
the DHA-treated children (P Z 0.028 and P Z 0.041, respectively).
Conclusions: DHA supplementation decreases liver and visceral fat, and ameliorates metabolic
abnormalities in children with NAFLD
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Imaging follow-up after liver transplantation
Full text linkLiver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures.Liver transplantation (LT) represents the best treatment for end-stage chronic liver disease, acute liver failure and early stages of hepatocellular carcinoma. Radiologists should be aware of surgical techniques to distinguish a normal appearance from pathological findings. Imaging modalities, such as ultrasound, CT and MR, provide for rapid and reliable detection of vascular and biliary complications after LT. The role of imaging in the evaluation of rejection and primary graft dysfunction is less defined. This article illustrates the main surgical anastomoses during LT, the normal appearance and complications of the liver parenchyma and vascular and biliary structures
Association between carotid artery and abdominal aortic aneurysm plaque
Full text linkBackground: The correlation between AAA and carotid artery plaque is unknown and a common etiology
and pathophysiology is suspected by some authors. The purpose of this work was to explore the association
between the features of a) carotid artery plaque and b) abdominal aortic aneurysm (AAA) plaques using
multi-detector-CT Angiography (MDCTA).
Methods: Forty-eight (32 males; median age 72 years) patients studied using a 16-detectors CT scanner were
retrospectively analyzed. A region of interest (ROI) ≥ 2 mm2 was used to quantify the HU value of the plaque
by two readers independently. Inter-observer reproducibility was calculated and Pearson correlation analysis was
performed.
Results: The Bland-Altman plots showed the inter-observer reproducibility to be good. The Pearson correlation was0.224 (95 % CI = 0.071 to 0.48), without statistically significant association between HU measured in the carotid artery plaque and in the AAA plaques (p = 0.138); after exclusion of the calcified plaques from the analysis, the rho values resulted 0.494 (95 % CI = 0.187 to 0.713) with a statistically significant association (p = 0.003).
Conclusion: In this study, we found an association between the features of the non calcific carotid plaque and the
features of AAA plaque
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