Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 153
Filtrar
1.
J Am Med Inform Assoc ; 29(12): 2050-2056, 2022 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-36206130

RESUMO

OBJECTIVE: Digital exposure notifications (DEN) systems were an emergency response to the coronavirus disease 2019 (COVID-19) pandemic, harnessing smartphone-based technology to enhance conventional pandemic response strategies such as contact tracing. We identify and describe performance measurement constructs relevant to the implementation of DEN tools: (1) reach (number of users enrolled in the intervention); (2) engagement (utilization of the intervention); and (3) effectiveness in preventing transmissions of COVID-19 (impact of the intervention). We also describe WA State's experience utilizing these constructs to design data-driven evaluation approaches. METHODS: We conducted an environmental scan of DEN documentation and relevant publications. Participation in multidisciplinary collaborative environments facilitated shared learning. Compilation of available data sources and their relevance to implementation and operation workflows were synthesized to develop implementation evaluation constructs. RESULTS: We identified 8 useful performance indicators within reach, engagement, and effectiveness constructs. DISCUSSION: We use implementation science to frame the evaluation of DEN tools by linking the theoretical constructs with the metrics available in the underlying disparate, deidentified, and aggregate data infrastructure. Our challenges in developing meaningful metrics include limited data science competencies in public health, validation of analytic methodologies in the complex and evolving pandemic environment, and the lack of integration with the public health infrastructure. CONCLUSION: Continued collaboration and multidisciplinary consensus activities can improve the utility of DEN tools for future public health emergencies.


Assuntos
COVID-19 , Humanos , Privacidade , Saúde Pública , Notificação de Doenças , Washington , Pandemias/prevenção & controle , Busca de Comunicante/métodos
2.
Public Health Rep ; 137(2_suppl): 96S-100S, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35915982

RESUMO

OBJECTIVES: Smartphone-based digital exposure notification (EN) tools were introduced during the COVID-19 pandemic to supplement strained case investigation and contact tracing efforts. We examined the influence of an EN tool implemented in Washington State, WA Notify, on user engagement in behaviors that protect against COVID-19 transmission. METHODS: From January 25 through June 30, 2021, we administered 2 surveys to WA Notify users who received notification of a possible COVID-19 exposure. The initial survey, sent when users received a notification, focused on intent to engage in protective behaviors. The follow-up survey captured data on self-reported actual engagement in protective behaviors and contact by a public health contact tracer. RESULTS: Of 1507 WA Notify users who completed the initial survey, 40.1% (n = 604) reported intending to seek COVID-19 testing and 67.1% (n = 1011) intended to watch for COVID-19 symptoms. Of 407 respondents to the follow-up survey, 57.5% (n = 234) reported getting tested and 84.3% (n = 343) reported watching for COVID-19 symptoms. Approximately 84% (n = 1266) of respondents to the initial survey received a notification from WA Notify before being reached by public health contact tracers; on follow-up, 42.5% (n = 173) of respondents reported never being contacted by public health. CONCLUSIONS: Our findings suggest that WA Notify users may initiate protective behaviors earlier than nonusers who will not know of an exposure until notified by public health or by a known contact. Digital EN tools may be a valuable addition to existing public health outbreak investigation and response activities.


Assuntos
COVID-19 , Humanos , COVID-19/epidemiologia , COVID-19/prevenção & controle , Pandemias/prevenção & controle , Teste para COVID-19 , Notificação de Doenças , Washington/epidemiologia
3.
Oncoimmunology ; 11(1): 2010905, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35481284

RESUMO

Current immunotherapies for lung cancer are only effective in a subset of patients. Identifying tumor-derived factors that facilitate immunosuppression offers the opportunity to develop novel strategies to supplement and improve current therapeutics. We sought to determine whether expression of driver oncogenes in lung cancer cells affects cytokine secretion, alters the local immune environment, and influences lung tumor progression. We demonstrate that oncogenic EGFR and KRAS mutations, which are early events in lung tumourigenesis, can drive cytokine and chemokine production by cancer cells. One of the most prominent changes was in CCL5, which was rapidly induced by KRASG12V or EGFRL858R expression, through MAPK activation. Immunocompetent mice implanted with syngeneic KRAS-mutant lung cancer cells deficient in CCL5 have decreased regulatory T cells (Tregs), evidence of T cell exhaustion, and reduced lung tumor burden, indicating tumor-cell CCL5 production contributes to an immune suppressive environment in the lungs. Furthermore, high CCL5 expression correlates with poor prognosis, immunosuppressive regulatory T cells, and alteration to CD8 effector function in lung adenocarcinoma patients. Our data support targeting CCL5 or CCL5 receptors on immune suppressive cells to prevent formation of an immune suppressive tumor microenvironment that promotes lung cancer progression and immunotherapy insensitivity.


Assuntos
Neoplasias Pulmonares , Proteínas Proto-Oncogênicas p21(ras) , Animais , Quimiocina CCL5/genética , Quimiocina CCL5/metabolismo , Citocinas/metabolismo , Receptores ErbB/metabolismo , Humanos , Pulmão/metabolismo , Pulmão/patologia , Neoplasias Pulmonares/genética , Camundongos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Microambiente Tumoral
4.
J Dent Res ; 101(9): 1046-1054, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35403466

RESUMO

Tobacco use is a well-established risk factor for multiple adverse oral conditions. Few nationally representative oral health data sets encompass the current diversity of tobacco and nicotine products. This investigation examines the validity of oral health measures in the Population Assessment of Tobacco and Health (PATH) Study to assess relationships between tobacco use and oral health. Cross-sectional data from PATH Study wave 4 (N = 33,643 US adults, collected 2016-2018) were used to obtain estimates for 6 self-reported oral conditions (e.g., bone loss around teeth, tooth extractions) and compared with analogous estimates from the National Health and Nutrition Examination Survey (NHANES) cycle 2017-2018 (N = 5,856). Within the PATH Study, associations were calculated between tobacco use status and lifetime and past 12-mo experience of adverse oral conditions using survey-weighted multivariable logistic regression. Nationally representative estimates of oral conditions between the PATH Study and NHANES were similar (e.g., ever-experience of bone loss around teeth: PATH Study 15.2%, 95% CI, 14.4%-15.9%; NHANES 16.6%, 95% CI, 14.9%-18.4%). In the PATH Study, combustible tobacco smoking was consistently associated with lifetime and past 12-mo experience of adverse oral health (e.g., exclusive cigarette smoking vs. never tobacco use, adjusted odds ratio [AOR] for loose teeth in past 12 mo: 2.02; 95% CI, 1.52-2.69). Exclusive smokeless tobacco use was associated with greater odds of loose teeth (AOR, 1.93; 95% CI, 1.15-3.26) and lifetime precancerous lesions (AOR, 3.85; 95% CI, 1.73-8.57). Use of other noncigarette products (e.g., pipes) was inconsistently associated with oral health outcomes. PATH Study oral health measures closely align with self-reported measures from NHANES and are internally concurrent. Observed associations with tobacco use and the ability to examine emerging tobacco products support application of PATH Study data in dental research, particularly to examine potential oral health effects of novel tobacco products and longitudinal changes in tobacco use behaviors.


Assuntos
Sistemas Eletrônicos de Liberação de Nicotina , Adulto , Estudos Transversais , Humanos , Inquéritos Nutricionais , Saúde Bucal , Tabaco , Estados Unidos/epidemiologia
5.
Trauma Violence Abuse ; 23(4): 1220-1234, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-33583357

RESUMO

Sexual assault and case attrition at the arrest stage are serious problems in the United States. Focal concerns have increasingly been used to explain police decision making in sexual assault cases. Because of the popularity of the focal concerns perspective and potential to inform evidence-based training, a systematic review and meta-analysis are needed to condense the literature. In this study, we assess the overall strength of the relationship between focal concerns variables and police decisions to arrest in cases of sexual assault. Our assessment of the effects of focal concerns variables on arrest decision making in sexual assault cases followed the systematic review protocols provided by the Campbell Collaboration of Systematic Reviews. Specifically, we used the Campbell Collaboration recommendations to search empirical literature and used meta-analysis to evaluate the size, direction, and strength of the impact of focal concerns variables on arrest decisions. Our search strategy detected 14 eligible studies and 79 effect sizes. The meta-analysis found several robust and statistically significant correlates of arrest. In fact, each focal concerns concept produced at least one robust arrest correlate. Overall, focal concerns offers a strong approach for explaining police decisions in sexual assault cases. Although practical concerns and resource constraints produced the strongest arrest correlates, results show the importance of additional case characteristics in officers' decision to arrest.


Assuntos
Vítimas de Crime , Delitos Sexuais , Tomada de Decisões , Humanos , Aplicação da Lei , Polícia , Estados Unidos
6.
Artigo em Inglês | MEDLINE | ID: mdl-34178242

RESUMO

Bluetooth exposure notification tools for mobile phones have emerged as one way to support public health contact tracing and mitigate the spread of COVID-19. Many states have launched their own versions of these tools. Washington State's exposure notification tool, WA Notify, became available on November 30, 2020, following a one-month Seattle campus pilot at the University of Washington. By the end of April 2021, 25% of the state's population had activated WA Notify, one of the highest adoption rates in the country. Washington State's formation of an Exposure Notification Advisory Committee, early pilot testing, and use of the EN Express system framework were all important factors in its adoption. Continuous monitoring and willingness to make early adjustments such as switching to automated texting of verification codes have also been important for improving the tool's value. Evaluation work is ongoing to determine and quantify WA Notify's effectiveness, timeliness, and accessibility.

7.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-21257951

RESUMO

BackgroundSecure and anonymous smartphone-based exposure notification tools are recently developed public health interventions that aim to reduce COVID-19 transmission and supplement traditional public health suriveillance. We assessed the impact of Washington States exposure notification tool, WA Notify, in mitigating the spread of COVID-19 during its first four months of implementation. MethodsDue to the constraints of privacy-preservation, aggregate metrics and disparate data sources were utilized to estimate the number of COVID-19 cases averted based on a modelling approach adapted from Wymant et al (2021) using the following parameters: number of notifications generated; the probability that a notified individual goes on to become a case; expected fraction of transmissions preventable by strict quarantine after notification; actual adherence to quarantine; and expected size of the full transmission chain if a contact had not been notified. ResultsThe model was run on a range of secondary attack rates (5.1%-13.706%) and quarantine effectiveness (53% and 64%). Assuming a 12.085% secondary attack rate and 53% quarantine effectiveness, the model shows that 5,500 cases (central 95% range of sensitivity analyses 2,800-8,200) were averted statewide during the first four months of its implementation. Based on an estimated COVID-19 case fatality of 1.4%, WA Notify saved 40-115 lives during the study period. ConclusionsThese findings demonstrate the value of exposure notification tools as a novel public health intervention to mitigate the spread of COVID-19 in the U.S. As new variants emerge and non-essential travel bans are lifted, exposure notification tools may continue to play a valuable role in limiting the spread of COVID-19.

8.
Clin Radiol ; 76(6): 452-457, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33637311

RESUMO

AIM: To evaluate the effectiveness of a novel, resorbable, spherical embolic agent compared with other established agents, by studying percentage fibroid infarction (the best indicator of long-term symptom improvement) in patients undergoing uterine fibroid embolisation (UFE). MATERIALS AND METHODS: This retrospective cohort study examined six different embolic agents used for fibroid embolisation, including a new gelatin-based, fully resorbable, spherical agent. The primary effectiveness outcomes were magnetic resonance imaging (MRI)-determined dominant fibroid infarct percentage (DF%) and all fibroid percentage infarct (AF%) at 3 months post-embolisation. MRI-determined uterine artery patency rate was the secondary outcome. Chi-squared test (χ2), relative risk (RR) calculation (primary outcomes), and analysis of variance (ANOVA) (secondary outcome) were the statistical tests employed. RESULTS: One hundred and twenty patients were treated with six embolic agents (20 consecutive patients per group, overall mean age 44.8±6.4, initial uterine volume 570±472 ml, dominant fibroid volume 249±324 ml). Fibroid infarctrates were similar between the cohorts with no significant difference between the new gelatin-based resorbable particle and other embolics in either DF% (χ2=3.92, p=0.56) or AF% (χ2=2.83, p=0.73). Complete DF% RR=1.07 (0.90-1.27) and AF% RR=1.09 (0.85-1.41) suggest non-inferiority of the resorbable particle (d=0.67, p<0.05). A favourable uterine artery patency rate was demonstrated for the resorbable particle compared with gelatin slurry (82.5% versus 27.5%, p<0.001 after Bonferroni adjustment). CONCLUSIONS: This new gelatin-based, fully resorbable particle is an effective embolic agent for fibroid embolisation and achieves an infarct rate non-inferior to established embolics.


Assuntos
Esponja de Gelatina Absorvível/uso terapêutico , Leiomioma/terapia , Embolização da Artéria Uterina/instrumentação , Embolização da Artéria Uterina/métodos , Neoplasias Uterinas/terapia , Adulto , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento , Artéria Uterina
9.
BMC Med Res Methodol ; 20(1): 30, 2020 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-32046643

RESUMO

BACKGROUND: There is broad recognition of the importance of evidence in informing clinical decisions. When information from all studies included in a systematic review ("review") does not contribute to a meta-analysis, decision-makers can be frustrated. Our objectives were to use the field of eyes and vision as a case study and examine the extent to which authors of Cochrane reviews conducted meta-analyses for their review's pre-specified main outcome domain and the reasons that some otherwise eligible studies were not incorporated into meta-analyses. METHODS: We examined all completed systematic reviews published by Cochrane Eyes and Vision, as of August 11, 2017. We extracted information about each review's outcomes and, using an algorithm, categorized one outcome as its "main" outcome. We calculated the percentage of included studies incorporated into meta-analyses for any outcome and for the main outcome. We examined reasons for non-inclusion of studies into the meta-analysis for the main outcome. RESULTS: We identified 175 completed reviews, of which 125 reviews included two or more studies. Across these 125 reviews, the median proportions of studies incorporated into at least one meta-analysis for any outcome and for the main outcome were 74% (interquartile range [IQR] 0-100%) and 28% (IQR 0-71%), respectively. Fifty-one reviews (41%) could not conduct a meta-analysis for the main outcome, mostly because fewer than two included studies measured the outcome (21/51 reviews) or the specific measurements for the outcome were inconsistent (16/51 reviews). CONCLUSIONS: Outcome choice during systematic reviews can lead to few eligible studies included in meta-analyses. Core outcome sets and improved reporting of outcomes can help solve some of these problems.


Assuntos
Medicina Baseada em Evidências/métodos , Avaliação de Resultados em Cuidados de Saúde/métodos , Revisões Sistemáticas como Assunto/métodos , Medicina Baseada em Evidências/normas , Medicina Baseada em Evidências/estatística & dados numéricos , Serviços de Saúde/normas , Serviços de Saúde/estatística & dados numéricos , Humanos , Metanálise como Assunto , Avaliação de Resultados em Cuidados de Saúde/normas , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Reprodutibilidade dos Testes , Revisões Sistemáticas como Assunto/normas
10.
Syst Rev ; 8(1): 334, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31862012

RESUMO

BACKGROUND: Conducting systematic reviews ("reviews") requires a great deal of effort and resources. Making data extracted during reviews available publicly could offer many benefits, including reducing unnecessary duplication of effort, standardizing data, supporting analyses to address secondary research questions, and facilitating methodologic research. Funded by the US Agency for Healthcare Research and Quality (AHRQ), the Systematic Review Data Repository (SRDR) is a free, web-based, open-source, data management and archival platform for reviews. Our specific objectives in this paper are to describe (1) the current extent of usage of SRDR and (2) the characteristics of all projects with publicly available data on the SRDR website. METHODS: We examined all projects with data made publicly available through SRDR as of November 12, 2019. We extracted information about the characteristics of these projects. Two investigators extracted and verified the data. RESULTS: SRDR has had 2552 individual user accounts belonging to users from 80 countries. Since SRDR's launch in 2012, data have been made available publicly for 152 of the 735 projects in SRDR (21%), at a rate of 24.5 projects per year, on average. Most projects are in clinical fields (144/152 projects; 95%); most have evaluated interventions (therapeutic or preventive) (109/152; 72%). The most frequent health areas addressed are mental and behavioral disorders (31/152; 20%) and diseases of the eye and ocular adnexa (23/152; 15%). Two-thirds of the projects (104/152; 67%) were funded by AHRQ, and one-sixth (23/152; 15%) are Cochrane reviews. The 152 projects each address a median of 3 research questions (IQR 1-5) and include a median of 70 studies (IQR 20-130). CONCLUSIONS: Until we arrive at a future in which the systematic review and broader research communities are comfortable with the accuracy of automated data extraction, re-use of data extracted by humans has the potential to help reduce redundancy and costs. The 152 projects with publicly available data through SRDR, and the more than 15,000 studies therein, are freely available to researchers and the general public who might be working on similar reviews or updates of reviews or who want access to the data for decision-making, meta-research, or other purposes.


Assuntos
Pesquisa Biomédica , Bases de Dados Factuais , Revisões Sistemáticas como Assunto , Humanos , Disseminação de Informação , Estados Unidos
11.
Breast Cancer Res ; 21(1): 103, 2019 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488209

RESUMO

BACKGROUND: Solid tumors produce proteins that can induce the accumulation of bone marrow-derived cells in various tissues, and these cells can enhance metastatic tumor growth by several mechanisms. 4T1 murine mammary tumors are known to produce granulocyte colony-stimulating factor (G-CSF) and increase the numbers of immunosuppressive CD11b+Gr1+ myeloid-derived suppressor cells (MDSCs) in tissues such as the spleen and lungs of tumor-bearing mice. While surgical resection of primary tumors decreases MDSC levels in the spleen, the longevity and impact of MDSCs and other immune cells in the lungs after tumor resection have been less studied. METHODS: We used mass cytometry time of flight (CyTOF) and flow cytometry to quantify MDSCs in the spleen, peripheral blood, and lungs of mice bearing orthotopic murine mammary tumors. We also tested the effect of primary tumor resection and/or gemcitabine treatment on the levels of MDSCs, other immune suppressor and effector cells, and metastatic tumor cells in the lungs. RESULTS: We have found that, similar to mice with 4T1 tumors, mice bearing metastatic 4T07 tumors also exhibit accumulation of CD11b+Gr1+ MDSCs in the spleen and lungs, while tissues of mice with non-metastatic 67NR tumors do not contain MDSCs. Mice with orthotopically implanted 4T1 tumors have increased granulocytic (G-) MDSCs, monocytic (M-) MDSCs, macrophages, eosinophils, and NK cells in the lungs. Resection of primary 4T1 tumors decreases G-MDSCs, M-MDSCs, and macrophages in the lungs within 48 h, but significant numbers of functional immunosuppressive G-MDSCs persist in the lungs for 2 weeks after tumor resection, indicative of an environment that can promote metastatic tumor growth. The chemotherapeutic agent gemcitabine depletes G-MDSCs, M-MDSCs, macrophages, and eosinophils in the lungs of 4T1 tumor-bearing mice, and we found that treating mice with gemcitabine after primary tumor resection decreases residual G-MDSCs in the lungs and decreases subsequent metastatic growth. CONCLUSIONS: Our data support the development of therapeutic strategies to target MDSCs and to monitor MDSC levels before and after primary tumor resection to enhance the effectiveness of immune-based therapies and improve the treatment of metastatic breast cancer in the clinic.


Assuntos
Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Neoplasias Pulmonares/secundário , Neoplasias Pulmonares/terapia , Neoplasias Mamárias Experimentais/patologia , Mastectomia , Células Supressoras Mieloides/efeitos dos fármacos , Animais , Antígenos Ly/metabolismo , Antígeno CD11b/metabolismo , Linhagem Celular Tumoral , Terapia Combinada , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Eosinófilos/patologia , Feminino , Células Matadoras Naturais/patologia , Neoplasias Pulmonares/imunologia , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Células Supressoras Mieloides/imunologia
12.
J Clin Epidemiol ; 115: 77-89, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31302205

RESUMO

OBJECTIVES: Data Abstraction Assistant (DAA) is a software for linking items abstracted into a data collection form for a systematic review to their locations in a study report. We conducted a randomized cross-over trial that compared DAA-facilitated single-data abstraction plus verification ("DAA verification"), single data abstraction plus verification ("regular verification"), and independent dual data abstraction plus adjudication ("independent abstraction"). STUDY DESIGN AND SETTING: This study is an online randomized cross-over trial with 26 pairs of data abstractors. Each pair abstracted data from six articles, two per approach. Outcomes were the proportion of errors and time taken. RESULTS: Overall proportion of errors was 17% for DAA verification, 16% for regular verification, and 15% for independent abstraction. DAA verification was associated with higher odds of errors when compared with regular verification (adjusted odds ratio [OR] = 1.08; 95% confidence interval [CI]: 0.99-1.17) or independent abstraction (adjusted OR = 1.12; 95% CI: 1.03-1.22). For each article, DAA verification took 20 minutes (95% CI: 1-40) longer than regular verification, but 46 minutes (95% CI: 26 to 66) shorter than independent abstraction. CONCLUSION: Independent abstraction may only be necessary for complex data items. DAA provides an audit trail that is crucial for reproducible research.


Assuntos
Indexação e Redação de Resumos/métodos , Revisões Sistemáticas como Assunto , Estudos Cross-Over , Coleta de Dados , Humanos , Razão de Chances , Distribuição Aleatória , Software , Adulto Jovem
13.
Magn Reson Med ; 81(5): 3138-3152, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30652347

RESUMO

PURPOSE: Implement simultaneous proton resonance frequency (PRF) shift and T1 measurements with equivalent temporal resolution using a single reference variable flip angle method. This novel method allows for simultaneous thermometry in both aqueous and fatty tissue. METHODS: This method acquires a single reference image at the lower flip angle and all dynamic images at the higher angle. T1 is calculated using a single reference variable flip angle method, which accounts for the reference image temperature remaining constant. Monte Carlo simulations determined the optimal dynamic flip angle for combined PRF and T1 measurements. This method was evaluated in MR-guided focused ultrasound heating experiments using a gelatin phantom and human cadaver breasts. In vivo measurement precision was demonstrated in healthy female volunteers under nonheating conditions. RESULTS: Temperature rise during MR-guided focused ultrasound heating was measured in aqueous tissue with both PRF and T1 . Both measures show good qualitative agreement in both space and time in aqueous tissue. The T1 change due to temperature increase was measured in fat, demonstrating the expected temporal response. The dynamic flip angle that produces optimal SNR for PRF measurements is lower than the optimal angle for T1 measurements, necessitating the selection of a compromise angle. CONCLUSION: The single reference variable flip angle method provides a reliable way to simultaneously measure PRF temperature and T1 change and overcomes PRF's inability to simultaneously monitor temperature in aqueous and adipose tissues. Future work will calibrate T1 change to temperature, enabling real-time temperature in fat and increasing patient safety and treatment efficacy during thermal interventional treatments.


Assuntos
Tecido Adiposo/diagnóstico por imagem , Mama/diagnóstico por imagem , Imageamento por Ressonância Magnética , Termometria/métodos , Algoritmos , Cadáver , Calibragem , Simulação por Computador , Feminino , Gelatina , Voluntários Saudáveis , Humanos , Processamento de Imagem Assistida por Computador , Método de Monte Carlo , Imagens de Fantasmas , Prótons , Valores de Referência , Reprodutibilidade dos Testes , Temperatura
14.
Magn Reson Med ; 81(1): 247-257, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30058224

RESUMO

PURPOSE: To construct a predictive model that describes how the duration and symmetry of a k-space-weighted image contrast (KWIC) window affects the temporal resolution of differently sized ultrasound foci when using a pseudo-golden angle stack-of-stars acquisition. METHODS: We performed a modulation analysis of proton resonance frequency temperature measurements to create the temporal modulation transfer function for KWIC windows of different symmetry and temporal duration. We reconstructed simulated ultrasound heating trajectories and stack-of-stars k-space data as well as experimental phantom data using the same trajectories. Images were reconstructed using symmetric and asymmetric KWIC windows of 3 different temporal durations. Simulated results were compared against temporal modulation transfer function predictions, experimental results, and the original simulated temperatures. RESULTS: The temporal modulation transfer function shows that temporal resolution with KWIC reconstructions depend on the object size. The KWIC window duration affected SNR and severity of undersampling artifacts. Accuracy and response delay improved as the KWIC window duration decreased or the size of the heated region within the KWIC plane increased. Precision worsened as the window duration decreased. Using a symmetric window eliminated the response delay to heated region size but introduced a large reconstruction delay. CONCLUSION: The accuracy and precision of proton resonance frequency temperature measurements from a stack-of-stars acquisition using a sliding KWIC window reconstruction are dependent on the size of the KWIC window and the size and shape of the heated region. The temporal modulation transfer function of KWIC reconstructions for any object size can predict the temporal response to changes in signal being acquired, such as temperature and contrast enhancement.


Assuntos
Mama/diagnóstico por imagem , Diagnóstico por Imagem , Processamento de Imagem Assistida por Computador/métodos , Termometria/métodos , Ultrassonografia , Acústica , Algoritmos , Artefatos , Simulação por Computador , Feminino , Análise de Fourier , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Distribuição Normal , Imagens de Fantasmas , Prótons , Reprodutibilidade dos Testes , Razão Sinal-Ruído , Temperatura
15.
Res Synth Methods ; 10(1): 2-14, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30325115

RESUMO

INTRODUCTION: During systematic reviews, data abstraction is labor- and time-intensive and error-prone. Existing data abstraction systems do not track specific locations and contexts of abstracted information. To address this limitation, we developed a software application, the Data Abstraction Assistant (DAA) and surveyed early users about their experience using DAA. FEATURES OF DAA: We designed DAA to encompass three essential features: (1) a platform for indicating the source of abstracted information, (2) compatibility with a variety of data abstraction systems, and (3) user-friendliness. HOW DAA FUNCTIONS: DAA (1) converts source documents from PDF to HTML format (to enable tracking of source of abstracted information), (2) transmits the HTML to the data abstraction system, and (3) displays the HTML in an area adjacent to the data abstraction form in the data abstraction system. The data abstractor can mark locations on the HTML that DAA associates with items on the data abstraction form. EXPERIENCES OF EARLY USERS OF DAA: When we surveyed 52 early users of DAA, 83% reported that using DAA was either very or somewhat easy; 71% are very or somewhat likely to use DAA in the future; and 87% are very or somewhat likely to recommend that others use DAA in the future. DISCUSSION: DAA, a user-friendly software for linking abstracted data with their exact source, is likely to be a very useful tool in the toolbox of systematic reviewers. DAA facilitates verification of abstracted data and provides an audit trail that is crucial for reproducible research.


Assuntos
Indexação e Redação de Resumos/métodos , Software , Revisões Sistemáticas como Assunto , Humanos , Internet , Reconhecimento Automatizado de Padrão , Linguagens de Programação , Reprodutibilidade dos Testes , Inquéritos e Questionários , Interface Usuário-Computador
16.
Cardiovasc Intervent Radiol ; 41(8): 1152-1159, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29484467

RESUMO

INTRODUCTION: As prostate artery embolisation (PAE) becomes an established treatment for benign prostatic obstruction, factors predicting good symptomatic outcome remain unclear. Pre-embolisation prostate size as a predictor is controversial with a handful of papers coming to conflicting conclusions. We aimed to investigate if an association existed in our patient cohort between prostate size and clinical benefit, in addition to evaluating percentage volume reduction as a predictor of symptomatic outcome following PAE. MATERIALS OR METHODS: Prospective follow-up of 86 PAE patients at a single institution between June 2012 and January 2016 was conducted (mean age 64.9 years, range 54-80 years). Multiple linear regression analysis was performed to assess strength of association between clinical improvement (change in IPSS) and other variables, of any statistical correlation, through Pearson's bivariate analysis. RESULTS: No major procedural complications were identified and clinical success was achieved in 72.1% (n = 62) at 12 months. Initial prostate size and percentage reduction were found to have a significant association with clinical improvement. Multiple linear regression analysis (r2 = 0.48) demonstrated that percentage volume reduction at 3 months (r = 0.68, p < 0.001) had the strongest correlation with good symptomatic improvement at 12 months after adjusting for confounding factors. CONCLUSION: Both the initial prostate size and percentage volume reduction at 3 months predict good symptomatic outcome at 12 months. These findings therefore aid patient selection and counselling to achieve optimal outcomes for men undergoing prostate artery embolisation.


Assuntos
Arteriopatias Oclusivas/terapia , Embolização Terapêutica/métodos , Próstata/irrigação sanguínea , Doenças Prostáticas/terapia , Idoso , Idoso de 80 Anos ou mais , Angiografia Digital/métodos , Arteriopatias Oclusivas/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Estudos Prospectivos , Próstata/diagnóstico por imagem , Próstata/patologia , Doenças Prostáticas/diagnóstico por imagem , Resultado do Tratamento
17.
Syst Rev ; 7(1): 25, 2018 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-29391059

RESUMO

BACKGROUND: While in its early years the HIV epidemic affected primarily the male and the young, nowadays, the population living with HIV/AIDS is approximately 24% women, and its age composition has shifted towards older ages. Many of the older women who live with HIV/AIDS also live with the medical and social conditions that accompany aging. This work aims to identify and characterize empirical studies of strategies for the comprehensive management of women over 40, including transgender women, who live with HIV/AIDS. Forty was chosen as an operational age cutoff to identify premenopausal women who are less likely to bear children, as well as peri- and postmenopausal women. METHODS: We conducted a literature search after discussions with a diverse panel of content experts and other stakeholders and developed an evidence map that identified 890 citations that address questions having to do with programs and barriers to engaging with programs, as well as the role of insurance and comorbidities, and have enrolled older women who live with HIV/AIDS. RESULTS: Of these, only 37 (4%) reported results of interest for women over 40 who live with HIV/AIDS, or examined interactions between gender and older age that would allow predictions in this subgroup. Few of the 37 eligible studies focused on women facing obvious challenges, such as immigrants, transgender, physically abused, or those recently released from prison. No studies focused on women caring for dependents, including children and grandchildren, or those diagnosed after age 40. CONCLUSION: The evidence base that is directly applicable to women over 40 who live with HIV/AIDS in the USA is limited, and the research need is broad. We propose research prioritization strategies for this population.


Assuntos
Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Adulto , Comorbidade , Feminino , Humanos , Qualidade de Vida , Estados Unidos/epidemiologia
18.
Syst Rev ; 7(1): 18, 2018 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-29368631

RESUMO

ᅟ: This is a response to a Letter. Data abstraction is a time-consuming and error-prone systematic review task. Shokraneh and Adams categorize available techniques for tracking data during data abstraction into three methods: simple annotation, descriptive addressing, and Cartesian coordinate system. While we agree with the categorization of the techniques, we disagree with the authors' statement that descriptive addressing is a PDF-independent method, i.e., any sort of descriptive addressing must reference a specific version of PDF file and not just any PDF of said report. Different versions of PDFs of the same report might place text and tables on different locations of the same page and/or on different pages. Consequently, it is our opinion that any kind of source location information should be accompanied by the source or linked by an intermediary service such as the Data Abstraction Assistant (DAA).


Assuntos
Antivirais , Hepatite C Crônica , Humanos
19.
Magn Reson Med ; 79(3): 1407-1419, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28643383

RESUMO

PURPOSE: Implement and evaluate a 3D MRI method to measure temperature changes with high spatial and temporal resolution and large field of view. METHODS: A multiecho pseudo-golden angle stack-of-stars (SOS) sequence with k-space weighted image contrast (KWIC) reconstruction was implemented to simultaneously measure multiple quantities, including temperature, initial signal magnitude M(0), transverse relaxation time ( T2*), and water/fat images. Respiration artifacts were corrected using self-navigation. KWIC artifacts were removed using a multi-baseline library. The phases of the multiple echo images were combined to improve proton resonance frequency precision. Temperature precision was tested through in vivo breast imaging (N = 5 healthy volunteers) using both coronal and sagittal orientations and with focused ultrasound (FUS) heating in a pork phantom using a breast specific MR-guided FUS system. RESULTS: Temperature measurement precision was significantly improved after echo combination when compared with the no echo combination case (spatial average of the standard deviation through time of 0.3-1.0 and 0.7-1.9°C, respectively). Temperature measurement accuracy during heating was comparable to a 3D seg-EPI sequence. M(0) and T2* values showed temperature dependence during heating in pork adipose tissue. CONCLUSION: A self-navigated 3D multiecho SOS sequence with dynamic KWIC reconstruction is a promising thermometry method that provides multiple temperature sensitive quantitative values. Magn Reson Med 79:1407-1419, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Assuntos
Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Termometria/métodos , Adulto , Algoritmos , Animais , Mama/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade , Imagens de Fantasmas , Suínos , Adulto Jovem
20.
Med Phys ; 44(11): 5930-5937, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28796308

RESUMO

PURPOSE: To study the accuracy and precision of T1 estimates using the Variable Flip Angle (VFA) method in 2D and 3D acquisitions. METHODS: Excitation profiles were simulated using numerical implementation of the Bloch equations for Hamming-windowed sinc excitation pulses with different time-bandwidth products (TBP) of 2, 6, and 10 and for T1 values of 295 ms and 1045 ms. Experimental data were collected in 5° increments from 5° to 90° for the same T1 and TBP values. T1 was calculated for every combination of flip angle with and without a correction for B1 and slice profile variation. Calculations were also made for flat slice profile such as obtained in 3D acquisition. Monte Carlo simulations were performed to obtain T1 measurement uncertainty. RESULTS: VFA T1 measurements in 2D without correction can result in a 40-80% underestimation of true T1 . Flip angle correction can reduce the underestimation, but results in accurate measurements of T1 only within a narrow band of flip angle combinations. The narrow band of accuracy increases with TBP, but remains too narrow for any practical range of T1 values or B1 variation. Simulated noisy VFA T1 measurements in 3D were accurate as long as the two angles chosen are on either side of the Ernst angle. CONCLUSIONS: Accurate T1 estimates from VFA 2D acquisitions are possible, but only a narrow range of T1 values within a narrow range of flip angle combinations can be accurately calculated using a 2D slice. Unless a better flip angle correction method is used, these results demonstrate that accurate measurements of T1 in 2D cannot be obtained robustly enough for practical use and are more likely obtained by a thin slab 3D VFA acquisition than from multiple-slice 2D acquisitions. VFA T1 measurements in 3D are accurate for wide ranges of flip angle combinations and T1 values.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Humanos , Modelos Teóricos , Método de Monte Carlo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...