Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 975
Filtrar
1.
Phys Rev Lett ; 132(16): 162501, 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38701469

RESUMO

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei ^{3}H and ^{3}He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, 0.6

2.
Sci Total Environ ; 926: 171760, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38537830

RESUMO

Ecosystems that offer carbon sequestration by leaching bicarbonate to groundwater are valuable natural capital. One region that may offer this service is the west coast of South Africa. Over 20 % is covered by soil mounds ("heuweltjies") up to 40 m diameter, 2 m high, inhabited by the southern harvester termite Microhodotermes viator and enriched in soil organic and inorganic carbon and soluble minerals. We aimed to generate radiogenic and stable isotope data for soils and groundwater in a region where these data are absent, to 1) verify the atmosphere-soil-groundwater link, and 2) resolve the timing and pattern of calcite dissolution and water infiltration in the landscape. Results show that soil and groundwater sulfate have the same marine aerosol source. Episodic calcite dissolution in mound centers, which increased during periods of global cooling, has been set against background input of marine aerosols since before the Last Glacial according to radiocarbon (14C) ages. Our data push back soil organic carbon 14C ages of inhabited termite mounds to 13-19 ka (kiloannum, thousand years before present), nest carbonate 14C ages to 33 ka, and mound soil carbonate 14C ages to 34 ka, making these the oldest active termite features ever dated. These ages are consistent with soil organic carbon and carbonate 14C ages of regional, non-mound, coastal petrocalcic horizons formed by accumulation of carbonate leached from their overlying aeolian dune fields. Harvesting activities of termites inject younger organic material around nests >1 m deep, leading to continuous renewal of important soil carbon reservoirs at depth. Termite bioturbation increases the system's ability to dissolve carbonate. The central, bioturbated part of the mounds have greater infiltration depths and greater calcite dissolution, whereas surrounding soils experienced more surface runoff. Calcareous termite mounds offer a mechanism to sequester CO2 through dissolution and leaching of soil carbonate-bicarbonate to groundwater.


Assuntos
Ecossistema , Isópteros , Animais , Solo , Carbono , Bicarbonatos , África do Sul , Carbonatos , Carbonato de Cálcio
3.
Clin Radiol ; 79(2): 117-123, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37989667

RESUMO

AIM: To evaluate variation in magnetic resonance imaging (MRI) technique and reporting of rectal cancer staging examinations across the UK. MATERIALS AND METHODS: A retrospective, multi-centre audit was undertaken of imaging protocols and information documented within consecutive MRI rectal cancer reports between March 2020 and August 2021, which were compared against American and European guidelines. Inclusion criteria included histologically proven rectal adenocarcinoma and baseline staging MRI rectum only. RESULTS: Fully anonymised data from 924 MRI reports by 78 radiologists at 24 centres were evaluated. Thirty-two per cent of radiologists used template reporting, but these reports offered superior documentation of 13 out of 18 key tumour features compared to free-text reports including T-stage, relation to peritoneal reflection and mesorectal fascia (MRF), nodal status, and presence of extramural venous invasion (EMVI; p<0.027 in each). There was no significant differences in the remaining five features. Across all tumour locations, the tumour relationship to the MRF, the presence of EMVI, and the presence of tumour deposits were reported in 79.5%, 85.6%, and 44% of cases, respectively, and tumour, nodal, and distant metastatic stage documented in 94.4%, 97.7%, and 78.3%. In low rectal tumours, the relationship to the anal sphincter complex was reported in only 54.6%. CONCLUSION: Considerable variation exists in rectal cancer MRI acquisition and reporting in this sample of UK centres. Inclusion of key radiological features in reports must be improved for risk stratification and treatment decisions. Template reporting is superior to free-text reporting. Routine adoption of standardised radiology practices should now be considered to improve standards to facilitate personalised precision treatment for patients to improve outcomes.


Assuntos
Radiologia , Neoplasias Retais , Humanos , Estudos Retrospectivos , Neoplasias Retais/patologia , Imageamento por Ressonância Magnética/métodos , Reino Unido , Estadiamento de Neoplasias , Invasividade Neoplásica/patologia
5.
Vaccine ; 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37833124

RESUMO

CatSper is a voltage dependent calcium ion channel present in the principal piece of sperm tail. It plays a crucial role in sperm hyperactivated motility and so in fertilization. Extracellular loops of mouse sperm CatSper were used to develop a vaccine to achieve protection from pregnancy. These loops were inserted at one of the three hypervariable regions of Human Papilloma Virus (HPV) capsid protein (L1). Recombinant vaccines were expressed in E.coli as inclusion body (IB), purified, refolded and assembled into virus-like particles (VLP) in vitro, and adsorbed on alum. Four vaccine candidates were tested in Balb/C mice. All the constructs proved immunogenic, one showed contraceptive efficacy. This recombinant contraceptive vaccine is a non-hormonal intervention and is expected to give long-acting protection from undesired pregnancies.

6.
Eur Rev Med Pharmacol Sci ; 27(4): 1625-1632, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36876707

RESUMO

OBJECTIVE: This study examines the role of MTHFR gene polymorphism (rs1801133) in women with lipedema (LIPPY) body composition parameters compared to a control group (CTRL). SUBJECTS AND METHODS: We carried out a study on a sample of 45 LIPPY and 50 women as a CTRL. Body composition parameters were examined by Dual-energy X-ray Absorptiometry (DXA). A genetic test was performed for the MTHFR polymorphism (rs1801133, 677C>T) using a saliva sample for LIPPY and CTRL groups. Mann-Whitney tests evaluated statistically significant differences between four groups (carriers and non-carriers of the MTHFR polymorphism for LIPPY and CTRL groups) on anthropometric/body composition parameters to identify patterns. RESULTS: LIPPY showed significantly higher (p<0.05) anthropometric parameters (weight, BMI, waist, abdominal, hip circumferences) and lower waist/hip ratio (p<0.05) compared to the CTRL group. The association between the polymorphism alleles related to the rs1801133 MTHFR gene and the body composition values LIPPY carriers (+) showed an increase in fat tissue of legs and fat region of legs percentage, arm's fat mass (g), leg's fat mass (g), and leg's lean mass (g) (p<0.05) compared to CTRL (+). Lean/fat arms and lean/fat legs were lower (p<0.05) in LIPPY (+) than in CTRL (+). In the LIPPY (+), the risk of developing the lipedema disease was 2.85 times higher (OR=2.85; p<0.05; 95% confidence interval = 0.842-8.625) with respect to LIPPY (-) and CTRL. CONCLUSIONS: The presence or absence of MTHFR polymorphism offers predictive parameters that could better characterize women with lipedema based on the association between body composition and MTHFR presence.


Assuntos
Lipedema , Metilenotetra-Hidrofolato Redutase (NADPH2) , Feminino , Humanos , Absorciometria de Fóton , Tecido Adiposo , Alelos , Composição Corporal , Lipedema/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética
7.
Eur Phys J Plus ; 138(1): 25, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36686498

RESUMO

In multiple stellar systems, interactions among the companion stars and their discs affect planet formation. In the circumstellar case, tidal truncation makes protoplanetary discs smaller, fainter and less long-lived than those evolving in isolation, thereby reducing the amount of material (gas and dust) available to assemble planetary embryos. On the contrary, in the circumbinary case the reduced accretion can increase the disc lifetime, with beneficial effects on planet formation. In this chapter we review the main observational results on discs in multiple stellar systems and discuss their possible explanations, focusing on recent numerical simulations, mainly dealing with dust dynamics and disc evolution. Finally, some open issues and future research directions are examined.

8.
Public Health ; 215: 17-26, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36608601

RESUMO

OBJECTIVES: This study systematically reviewed scientific evidence regarding the impact of economic growth on physical activity (PA) and sedentary behaviors. METHODS: A keyword and reference search was conducted in PubMed, Web of Science, Cochrane Library, Scopus, and EBSCO from the inception of an electronic bibliographic database to November 2021. Studies that met all of the following criteria were included in the review: (1) study designs: observational studies; (2) study subjects: people of all ages; (3) exposure: macroeconomic growth; (4) outcomes: PA or sedentary behaviors/sitting time. RESULTS: 15 studies were identified. Eight among 12 studies found economic growth positively associated with at least one domain/measure of PA, whereas the remaining four found an inverse relationship. One of two studies examined the association of economic growth and physical inactivity found a positive relationship, while another found no significant relationship. Four studies examined the associations between economic growth and sedentary behaviors, and the results were inconclusive. The impact of economic growth on PA is through three main pathways-(a) building and maintaining parks and green spaces, (b) adoption of the modern workplace and high technology, and (c) motorized transportation. CONCLUSION: Building and maintaining parks and green spaces can effectively promote leisure time physical activity and active commute in developed countries, whereas promoting workplace and transportation-related PA could be prioritized in developing nations. Future research calls for longitudinal study design and further exploration of macro-environmental factors. Policymakers and stakeholders should be informed about the potential PA reduction resulting from economic growth and develop preventive strategies to alleviate the problem.


Assuntos
Desenvolvimento Econômico , Comportamento Sedentário , Humanos , Estudos Longitudinais , Exercício Físico , Atividade Motora
9.
Edmonton; Obesity Canada; Version 2; Oct. 21, 2022. 28 p.
Não convencional em Inglês | BIGG - guias GRADE | ID: biblio-1509679

RESUMO

Healthy eating is important for all Canadians, regardless of body size, weight or health condition. Key messages from Canada's Food Guide for Healthy Eating can be used as a foundation for nutrition and food-related education (Figure 1). Use evidence-based nutrition resources to give your patients nutrition and behaviour change advice that aligns with their values, preferences and social determinants of health. (Figure 1) There is no one-size-fits-all eating pattern for obesity management. Adults living with obesity may consider various nutrition intervention options that are client-centred and flexible. Evidence suggests this approach will better facilitate long-term adherence. (Table 1, Figure 2) Nutrition interventions for obesity management should focus on achieving health outcomes for chronic disease risk reduction and quality of life improvements, not just weight changes. 5 Table 2 outlines health-related outcomes to support patients/clients in obesity management. Nutrition interventions for obesity management should emphasize individualized eating patterns, food quality and a healthy relationship with food. Including mindfulness-based eating practices that may help lower food cravings, reduce reward-driven eating, improve body satisfaction and improve awareness of hunger and satiety. 6­11 Caloric restriction can achieve short-term reductions in weight (i.e.< 12 months) but has not shown to be sustainable long-term (i.e. > 12 months). Caloric restriction may affect neurobiological pathways that control appetite, hunger, cravings and body weight regulation that may result in increased food intake and weight gain.64-66 People living with obesity are at increased risk for micronutrient deficiencies including but not limited to vitamin D, vitamin B12 and iron deficiencies. Restrictive eating patterns and obesity treatments (e.g. medications, bariatric surgery) may also result in micronutrient deficiencies and malnutrition. Assessment including biochemical values can help inform recommendations for food intake, vitamin/mineral supplements, and possible drug-nutrient interactions. Collaborate care with a registered dietitian who has experience in obesity management and medical nutrition therapy. 12 Dietitians can support people living with obesity who also have other chronic diseases, malnutrition, food insecurity or disordered patterns of eating. Future research should use nutrition-related outcomes and health behaviours in addition to weight and body composition outcomes. Characterization of population sample collections should use the updated definition of obesity as a chronic, progressive and relapsing disease characterized by the presence of adiposity that impairs health and social well-being rather than BMI exclusively. Qualitative data is needed to understand the lived experience of people with obesity.


Assuntos
Humanos , Restrição Calórica , Programas de Redução de Peso , Manejo da Obesidade , Obesidade/dietoterapia , Pressão Arterial , Controle Glicêmico
10.
Nature ; 609(7925): 41-45, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36045235

RESUMO

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure1-3, and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements3-5. Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements6-8 have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction.

11.
Phys Rev Lett ; 129(4): 042501, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35939025

RESUMO

We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733 fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model) fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

13.
Faraday Discuss ; 236(0): 389-411, 2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-35543123

RESUMO

Valence electronic structure is crucial for understanding and predicting reactivity. Valence non-resonant X-ray photoelectron spectroscopy (NRXPS) provides a direct method for probing the overall valence electronic structure. However, it is often difficult to separate the varying contributions to NRXPS; for example, contributions of solutes in solvents or functional groups in complex molecules. In this work we show that valence resonant X-ray photoelectron spectroscopy (RXPS) is a vital tool for obtaining atomic contributions to valence states. We combine RXPS with NRXPS and density functional theory calculations to demonstrate the validity of using RXPS to identify atomic contributions for a range of solutes (both neutral and ionic) and solvents (both molecular solvents and ionic liquids). Furthermore, the one-electron picture of RXPS holds for all of the closed shell molecules/ions studied, although the situation for an open-shell metal complex is more complicated. The factors needed to obtain a strong RXPS signal are investigated in order to predict the types of systems RXPS will work best for; a balance of element electronegativity and bonding type is found to be important. Additionally, the dependence of RXPS spectra on both varying solvation environment and varying local-covalent bonding is probed. We find that RXPS is a promising fingerprint method for identifying species in solution, due to the spectral shape having a strong dependence on local-covalency but a weak dependence on the solvation environment.

14.
Phys Rev Lett ; 128(14): 142501, 2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35476486

RESUMO

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing ≲50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.

15.
JAMA Neurol ; 79(2): 131-140, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-34962574

RESUMO

Importance: Many people with Parkinson disease (PD) develop motor complications that are uncontrolled by levodopa dose adjustment. Among these patients, it is uncertain which drug class is more effective as adjuvant therapy. Objective: To compare the long-term effects on patient-rated quality of life of adding a dopamine agonist vs a dopamine reuptake inhibitor (DRI), either a monoamine oxidase type B (MAO-B) inhibitor or a catechol-O-methyltransferase (COMT) inhibitor, to levodopa therapy for the treatment of patients with motor complications of PD. Design, Setting, and Participants: This pragmatic semifactorial (2 × 1) randomized clinical trial recruited from 64 neurology and geriatric clinics (62 in the United Kingdom, 1 in the Czech Republic, and 1 in Russia) between February 23, 2001, and December 15, 2009. A total of 500 patients with idiopathic PD who developed uncontrolled motor complications and did not have dementia were randomly assigned on a 1:1:1 basis using a computerized minimization program. Data were analyzed between 2017 and 2020. Interventions: Open-label dopamine agonist, MAO-B inhibitor, or COMT inhibitor. Main Outcomes and Measures: Primary outcomes were scores on the 39-item Parkinson's Disease Questionnaire (PDQ-39) mobility domain and cost-effectiveness. Outcomes were assessed before study entry, at 6 and 12 months after randomization, and annually thereafter. Repeated-measures and log rank analyses were used in an intention-to-treat approach. Results: Among 500 participants, the mean (SD) age was 73.0 (8.2) years; 314 participants (62.8%) were men. Over a median of 4.5 years (range, 0-13.3 years) of follow-up, the participants in the dopamine agonist group had a mean PDQ-39 mobility score that was 2.4 points (95% CI, -1.3 to 6.0 points) better than that of the combined MAO-B and COMT groups; however, this difference was not significant (P=.20). With regard to DRIs, participants in the MAO-B group had mean PDQ-39 mobility scores that were 4.2 points (95% CI, 0.4-7.9 points; P=.03) better than those of the COMT group and EuroQol 5-dimension 3-level (EQ-5D-3L) utility scores that were 0.05 points (95% CI, 0.003-0.09 points; P=.04) better than the COMT group. Nonsignificant improvements were found in the PDQ-39 summary index (mean difference, 2.2 points; 95% CI, -0.2 to 4.5 points; P=.07) along with nonsignificant reductions in dementia (rate ratio [RR], 0.70; 95% CI, 0.47-1.03; P = .07) and mortality (RR, 0.76; 95% CI, 0.56-1.03; P=.07). When dopamine agonists were compared with MAO-B inhibitors only, the outcomes were similar. Conclusions and Relevance: In this study, patient-rated quality of life was inferior when COMT inhibitors were used as adjuvant treatment compared with MAO-B inhibitors or dopamine agonists among people with PD who experienced motor complications that were uncontrolled by levodopa therapy. The MAO-B inhibitors produced equivalent disease control, suggesting that these agents may be underused as adjuvant therapy. Trial Registration: isrctn.org Identifier: ISRCTN69812316; EU Clinical Trials Register Identifier: 2005-001813-16.


Assuntos
Antiparkinsonianos/uso terapêutico , Inibidores de Catecol O-Metiltransferase/uso terapêutico , Quimioterapia Adjuvante/métodos , Agonistas de Dopamina/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Levodopa/uso terapêutico , Inibidores da Monoaminoxidase/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , Antiparkinsonianos/efeitos adversos , Catecol O-Metiltransferase , Quimioterapia Adjuvante/efeitos adversos , Agonistas de Dopamina/efeitos adversos , Inibidores Enzimáticos/efeitos adversos , Feminino , Humanos , Levodopa/efeitos adversos , Masculino , Pessoa de Meia-Idade , Inibidores da Monoaminoxidase/efeitos adversos , Transtornos dos Movimentos/tratamento farmacológico , Transtornos dos Movimentos/etiologia , Qualidade de Vida , Resultado do Tratamento
16.
Ir J Psychol Med ; : 1-10, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33966668

RESUMO

OBJECTIVES: The objective of this study was to understand the variables or study habits that inform study in undergraduate and postgraduate students attending Trinity College Dublin. METHODS: A descriptive, cross-sectional anonymous online survey was used to gather data to explore student study habits. Survey 1 was completed by participants in April 2019 and survey 2 was completed by participants in April 2020, during the COVID-19 restrictions. RESULTS: A total of 1557 participants completed survey 1 in 2019, and 1793 participants completed survey 2 in 2020. In both surveys a majority reported using caffeine, library study, sleep pattern adjustment and excercise to aid academic performance. Survey 2 participants reported COVID-19 resulted in increased difficulty studying (91%). In particular loss of structure and routine was negatively impacted by the pandemic (92%), and increased feelings of stress were reported (75%). CONCLUSIONS: Our study suggests a potential role of the college environment as a target for the implementation of interventions to promote student learning, healthy study habits and well-being. The global pandemic has resulted in additional challenging demands for universities to serve an essential role in supporting college students study habits.

17.
Phys Rev Lett ; 126(17): 172502, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33988387

RESUMO

We report a precision measurement of the parity-violating asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{208}Pb. We measure A_{PV}=550±16(stat)±8(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(Q^{2}=0.00616 GeV^{2})=0.368±0.013. Combined with our previous measurement, the extracted neutron skin thickness is R_{n}-R_{p}=0.283±0.071 fm. The result also yields the first significant direct measurement of the interior weak density of ^{208}Pb: ρ_{W}^{0}=-0.0796±0.0036(exp)±0.0013(theo) fm^{-3} leading to the interior baryon density ρ_{b}^{0}=0.1480±0.0036(exp)±0.0013(theo) fm^{-3}. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars.

19.
Clin Radiol ; 76(5): 333-341, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33461746

RESUMO

AIM: To establish the diagnostic accuracy of the Liver Imaging Reporting and Data System (LI-RADS) for hepatocellular carcinoma (HCC) and compare its performance to that of international criteria from European Assofor the Study of the Liver (EASL), Japan Society of Hepatology (JSH), Asian Pacific Association for the Study of the Liver (APASL), and Organ Procurement and Transplantation Network (OPTN), and to the reporting radiologist's overall opinion regarding the probability of a nodule being a HCC by correlating with a histological diagnosis from whole liver explants. MATERIALS AND METHODS: The present single-centre, retrospective review selected participants based on the following criteria: adults (≥18 years) listed for liver transplantation in 2014/2015, with liver cirrhosis at the time of magnetic resonance imaging (MRI) with hepatocyte specific contrast agent, and at least one liver lesion ≥10 mm on MRI with histology from subsequent liver explant for comparison. Each lesion was assessed against international criteria and given a "radiologist opinion" score of 1-5 (1 = definitely benign, 5 = definitely HCC). RESULTS: Total 268 patient records were reviewed, with 105 eligible lesions identified from 47 patients. Median lesion size was 15.5 mm (range 10-68 mm). Sensitivity (%), specificity (%), and positive predictive value (PPV; %) for LI-RADS LR5 was 45, 89, and 89, for LI-RADS LR4+5 + TIV was 61, 80, and 86, for EASL was 44, 86 and 86, for JSH/APASL was 64, 81, and 87, for OPTN was 36, 90, and 88, and for "radiologist impression" of probably or definitely HCC was 79, 79, and 88 respectively. CONCLUSIONS: MRI has moderate sensitivity and good specificity for the diagnosis of HCC with considerable variation depending on criteria used. OPTN criteria have the best specificity, but low sensitivity. "Radiologist opinion" gives highest overall accuracy with increases in sensitivity and reduction in specificity when compared to the imaging criteria.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Gadolínio DTPA , Aumento da Imagem/métodos , Cirrose Hepática/complicações , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Sistemas de Informação em Radiologia , Adulto , Idoso , Carcinoma Hepatocelular/complicações , Carcinoma Hepatocelular/patologia , Meios de Contraste , Feminino , Humanos , Fígado/diagnóstico por imagem , Fígado/patologia , Cirrose Hepática/patologia , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/patologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...