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1.
Proc Natl Acad Sci U S A ; 119(17): e2120439119, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35412862

RESUMO

Long-duration spaceflight induces changes to the brain and cerebrospinal fluid compartments and visual acuity problems known as spaceflight-associated neuro-ocular syndrome (SANS). The clinical relevance of these changes and whether they equally affect crews of different space agencies remain unknown. We used MRI to analyze the alterations occurring in the perivascular spaces (PVS) in NASA and European Space Agency astronauts and Roscosmos cosmonauts after a 6-mo spaceflight on the International Space Station (ISS). We found increased volume of basal ganglia PVS and white matter PVS (WM-PVS) after spaceflight, which was more prominent in the NASA crew than the Roscosmos crew. Moreover, both crews demonstrated a similar degree of lateral ventricle enlargement and decreased subarachnoid space at the vertex, which was correlated with WM-PVS enlargement. As all crews experienced the same environment aboard the ISS, the differences in WM-PVS enlargement may have been due to, among other factors, differences in the use of countermeasures and high-resistive exercise regimes, which can influence brain fluid redistribution. Moreover, NASA astronauts who developed SANS had greater pre- and postflight WM-PVS volumes than those unaffected. These results provide evidence for a potential link between WM-PVS fluid and SANS.


Assuntos
Astronautas , Líquido Cefalorraquidiano , Sistema Glinfático , Voo Espacial , Transtornos da Visão , Líquido Cefalorraquidiano/diagnóstico por imagem , Sistema Glinfático/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Transtornos da Visão/líquido cefalorraquidiano , Transtornos da Visão/diagnóstico por imagem , Substância Branca/diagnóstico por imagem
2.
Pediatr Emerg Care ; 38(6): e1332-e1335, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35639437

RESUMO

OBJECTIVES: Ovarian torsion (OT) is an emergency that mandates early detection and surgical detorsion to avoid catastrophic consequences of further adnexal injury. Prompt ultrasound is critical for accurate diagnosis. Traditionally, evaluation of arterial and venous flow was used as a diagnostic tool for OT, but recent radiologic research has indicated that ovarian size and size discrepancy between sides is a better diagnostic criterion. This study seeks to determine whether ovarian size discrepancy or vascular flow to the ovary is more accurate in the diagnosis of OT in the pediatric emergency population and to better describe symptoms that distinguish OT from other abdominal and pelvic pathology. METHODS: This was a retrospective, cross-sectional study evaluating all female pediatric patients, aged 1 to 18 years, who underwent a pelvic ultrasound to evaluate for OT over a 2-year period in our pediatric emergency department. Patients suitable for inclusion were identified via Nuance mPowerTM, a search engine that provides clinical analytics based on radiology reports generated within our institution. RESULTS: We reviewed the medical records of 193 female patients aged 1 to 18 years, all of whom had a pelvic ultrasound (with or without Doppler) to evaluate for OT during the study period. In comparing ovarian size on ultrasound, patients with OT had a significantly larger magnitude of difference in ovarian volume than patients without torsion (5.57× [interquartile range, 3-12.5] vs 1.56× [interquartile range, 1.24-2.25; P < 0.001]). Ovarian torsion was associated with a 33-fold increased risk of lack of arterial flow (relative risk, 33.33) and with a 9-fold increased risk of lack of venous flow (relative risk, 9.27), when compared with those patients without OT. Patients with OT were significantly more likely to have emesis and peritoneal signs on examination, as well as previous history of OT (P = 0.01, 0.02, and 0.002, respectively) than those without OT. All patients with OT reported abdominal pain. CONCLUSIONS: We found that a large size discrepancy between ovaries is indicative of OT. Our data also suggest that presence of Doppler flow on ultrasound cannot be used to exclude OT but that lack of Doppler flow on ultrasound is a significant diagnostic marker. As previous studies have also found, clinical symptoms of OT are nonspecific and do not offer any certainty in differentiating OT from other pathologies.


Assuntos
Doenças Ovarianas , Torção Ovariana , Criança , Estudos Transversais , Feminino , Humanos , Doenças Ovarianas/diagnóstico por imagem , Torção Ovariana/diagnóstico por imagem , Estudos Retrospectivos , Anormalidade Torcional/diagnóstico por imagem , Anormalidade Torcional/cirurgia
3.
Neuroradiology ; 63(8): 1271-1281, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33587162

RESUMO

PURPOSE: Following prolonged stays on the International Space Station (ISS), some astronauts exhibit visual acuity changes, ophthalmological findings, and mildly elevated intracranial pressures as part of a novel process called spaceflight-associated neuro-ocular syndrome (SANS). To determine the pathophysiology of SANS, NASA conducted a multi-investigator study in which 11 healthy participants underwent head-down tilt bed rest, mimicking microgravity-induced cephalad fluid shifts, combined with elevated ambient CO2 levels similar to those on the ISS (HDT+CO2). As part of that study, we examined the effects of HDT+CO2 on cerebral perfusion. METHODS: Using arterial spin labeling, we compared cerebral perfusion before, during, and after HDT+CO2 in participants who developed SANS (n = 5) with those who did not (n = 6). RESULTS: All participants demonstrated a decrease in perfusion during HDT+CO2 (mean decrease of 25.1% at HDT7 and 16.2% at HDT29); however, the timing and degree of change varied between the groups. At day 7 of HDT+CO2, the SANS group experienced a greater reduction in perfusion than the non-SANS group (p =.05, 95% CI:-0.19 to 16.11, d=.94, large effect). Conversely, by day 29 of HDT+CO2, the SANS group had significantly higher perfusion (approaching their baseline) than the non-SANS group (p = .04, 95% CI:0.33 to 13.07, d=1.01, large effect). CONCLUSION: Compared with baseline and recovery, HDT+CO2 resulted in reduced cerebral perfusion which varied based on SANS status. Further studies are needed to unravel the relative role of HDT vs hypercapnia, to determine if these perfusion changes are clinically relevant, and whether perfusion changes contribute to the development of SANS during spaceflight.


Assuntos
Decúbito Inclinado com Rebaixamento da Cabeça , Voo Espacial , Repouso em Cama , Circulação Cerebrovascular , Humanos , Hipercapnia , Perfusão
4.
Perception ; 50(10): 842-860, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34623190

RESUMO

It is well known that adults spontaneously classify people into social categories and this categorization in turn guides their cognition and behavior. A wealth of research has examined how people perceive race and investigated the effect of race on social behavior. But what about race encoding? Although considerable behavioral research has investigated the encoding of race, that is, the social categorization by race, the neural underpinning of it is largely underexplored. To investigate the time course of race encoding, the current study employed a modified category verification task and a multivariate analyzing approach. We found that racial information became decodable from event-related potential topographies as early as about 200 ms after stimulus onset. At this stage, the brain can differentiate different races in a task-relevant manner. Nonetheless, it is not until 100 ms later that racial information is encoded in a socially relevant manner (own- versus other-race). Importantly, perceptual differentiation not only occurs before the encoding of the race but actually influences it: the faces that are more easily perceptually categorized are actually encoded more readily. Together, we posit that the detection and the encoding of race are decoupled although they are not completely independent. Our results provide powerful constraints toward the theory-building of race.


Assuntos
Reconhecimento Facial , Encéfalo , Potenciais Evocados , Humanos , Reconhecimento Visual de Modelos , Grupos Raciais
5.
N Engl J Med ; 377(18): 1746-1753, 2017 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-29091569

RESUMO

BACKGROUND: There is limited information regarding the effects of spaceflight on the anatomical configuration of the brain and on cerebrospinal fluid (CSF) spaces. METHODS: We used magnetic resonance imaging (MRI) to compare images of 18 astronauts' brains before and after missions of long duration, involving stays on the International Space Station, and of 16 astronauts' brains before and after missions of short duration, involving participation in the Space Shuttle Program. Images were interpreted by readers who were unaware of the flight duration. We also generated paired preflight and postflight MRI cine clips derived from high-resolution, three-dimensional imaging of 12 astronauts after long-duration flights and from 6 astronauts after short-duration flights in order to assess the extent of narrowing of CSF spaces and the displacement of brain structures. We also compared preflight ventricular volumes with postflight ventricular volumes by means of an automated analysis of T1-weighted MRIs. The main prespecified analyses focused on the change in the volume of the central sulcus, the change in the volume of CSF spaces at the vertex, and vertical displacement of the brain. RESULTS: Narrowing of the central sulcus occurred in 17 of 18 astronauts after long-duration flights (mean flight time, 164.8 days) and in 3 of 16 astronauts after short-duration flights (mean flight time, 13.6 days) (P<0.001). Cine clips from a subgroup of astronauts showed an upward shift of the brain after all long-duration flights (12 astronauts) but not after short-duration flights (6 astronauts) and narrowing of CSF spaces at the vertex after all long-duration flights (12 astronauts) and in 1 of 6 astronauts after short-duration flights. Three astronauts in the long-duration group had optic-disk edema, and all 3 had narrowing of the central sulcus. A cine clip was available for 1 of these 3 astronauts, and the cine clip showed upward shift of the brain. CONCLUSIONS: Narrowing of the central sulcus, upward shift of the brain, and narrowing of CSF spaces at the vertex occurred frequently and predominantly in astronauts after long-duration flights. Further investigation, including repeated postflight imaging conducted after some time on Earth, is required to determine the duration and clinical significance of these changes. (Funded by the National Aeronautics and Space Administration.).


Assuntos
Astronautas , Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Ventrículos Cerebrais/anatomia & histologia , Imageamento por Ressonância Magnética , Voo Espacial , Ausência de Peso/efeitos adversos , Ventrículos Cerebrais/diagnóstico por imagem , Cérebro/anatomia & histologia , Cérebro/diagnóstico por imagem , Humanos , Pressão Intracraniana , Pessoa de Meia-Idade , Fatores de Tempo , Transtornos da Visão/etiologia
6.
Emerg Radiol ; 24(1): 39-45, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27620896

RESUMO

Subdural hematomas (SDHs) comprise a significant percentage of missed intracranial hemorrhage on axial brain CT. SDH detection rates could be improved with the addition of reformatted images. Though performed at some centers, the potential additional diagnostic sensitivity of reformatted images has not yet been investigated. The purpose of our study is to determine if the addition of coronal and sagittal reformatted images to an axial brain CT increases the sensitivity and specificity for detection of acute traumatic SDH. We retrospectively reviewed consecutive brain CTs acquired for acute trauma that contained new SDHs. An equivalent number of normal brain CTs served as control. Paired sets of images were created for each case: (1) axial images only ("axial only") and (2) axial, coronal, sagittal images ("reformat added"). Three readers interpreted both the axial only and companion reformat added for each case, separated by 1 month. Reading times and SDH detection rates were compared. One hundred SDH and 100 negative examinations were collected. Sensitivity and specificity for the axial-only scans were 75.7 and 94.3 %, respectively, compared with 88.3 and 98.3 % for reformat added. There was a 24.3 % false negative (missed SDH) rate with axial-only scans versus 11.7 % with reformat added (p = <0.001). Median reader interpretation times were longer with the addition of reformatted images (125 versus 89 s), but this difference was not significant (p = 0.23). The addition of coronal and sagittal images in trauma brain CT resulted in improved sensitivity and specificity as well as a reduction in SDH false negatives by greater than 50 %. Reformatted images substantially reduce the number of missed SDHs compared with axial images alone.


Assuntos
Hematoma Subdural/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Feminino , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Software
7.
Pediatr Radiol ; 46(5): 660-5, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26860095

RESUMO

BACKGROUND: In spite of decades of experience with the procedure, controversy persists as to the overall distress experienced by children and the routine need for sedation in children undergoing voiding cystourethrograms (VCUG). Many studies have attempted to address these issues, often divided into one camp that champions routine sedation while another group believes that pretest preparation is often all that is needed. At the root of these issues are some of the limitations of previous studies as most incorporate inherently subjective parental questionnaires to determine distress levels rather than using an objective, unbiased observer. OBJECTIVE: The objective of this study is to use a validated and reliable tool (the brief behavioral distress scale) to objectively evaluate the distress experienced during VCUGs. MATERIALS AND METHODS: A prospective study of 26 children (ages 3-7 years old) was performed by the pediatric radiology department at a large urban academic medical center. Patients were evaluated for distress during 12 separate VCUG steps beginning with the patient entering the room and ending with the clothing being replaced at study completion. RESULTS: Using a general linear model (repeated measures analysis of variance (ANOVA)), significant distress was identified during two phases of the examination, catheter insertion (P-values ranging <0.001-0.19) and the full bladder phase (P-values ranging 0.005-0.043). The mean distress score for catheter insertion (mean: 1.38, standard deviation [SD]: 1.098) was nearly three times higher than the next most distressful step, i.e. full bladder (mean: 0.65, SD: 0.745). Additionally, entering the room was perceived as significantly more distressing than the catheter out (P = 0.016) and clothing replacement phase (P = 0.006). CONCLUSION: We find that despite there being significantly increased distress during the catheter insertion and full bladder phases, the distress levels during VCUGs are markedly less than in previous reports. Even the most distressful stage, catheterization, was less stressful than previously reported with levels closer to that of minor distress evinced by comfort-seeking behavior from a parent rather than more significant distress resulting in screaming. Our findings corroborate and expand on the conclusion of the effectiveness of pretest preparation and child life specialist involvement.


Assuntos
Transtornos do Comportamento Infantil/psicologia , Estresse Psicológico/prevenção & controle , Estresse Psicológico/psicologia , Transtornos Urinários/diagnóstico por imagem , Urografia/psicologia , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Medição da Dor , Estudos Prospectivos , Micção
8.
Educ Health (Abingdon) ; 28(1): 68-73, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26261118

RESUMO

BACKGROUND: The purpose of this manuscript is to present a newly instituted program for resident scholarly activity that includes a curriculum designed to enhance resident training with regard to research while meeting requirements established by the Accreditation Council for Graduate Medical Education (ACGME), the governing body responsible for regulation of post-graduate medical education and training in the United States. METHODS: A scholarly activity program was designed with the following goals: (i) enhance the academic training environment for our residents; (ii) foster interests in research and academic career paths; (iii) provide basic education on research methodology and presentation skills. To guide program design, an electronic survey was created and distributed to the residents and faculty in the Department of Radiology and Radiological Sciences at the Medical University of South Carolina (MUSC), a 750-bed public teaching hospital in the state of South Carolina in the United States. RESULTS: Survey respondents were in strong support of a required resident scholarly activity project (70% in favor), felt non-traditional projects were valuable (84.1% of respondents), and were proponents of required scholarly activity summary presentations (58%). This program requires that residents engage in a scholarly activity project under the guidance of a mentor. Resident success is maximized through in-house education initiatives focusing on presentation and research skills, protected time to work on the project, and oversight by a radiology research committee. All residents present a summary of their work near the end of their residency training. DISCUSSION: Changes to the radiology resident certification process create an opportunity for incorporating new policies aimed at enhancing resident education. The scholarly activity program outlined in this manuscript is one such initiative designed to meet ACGME requirements, provide an introduction to research, and establish a scholarly activity project requirement.


Assuntos
Pesquisa Biomédica/educação , Educação de Pós-Graduação em Medicina/normas , Internato e Residência/normas , Radiologia/educação , Pesquisa Biomédica/normas , Escolha da Profissão , Currículo , Educação de Pós-Graduação em Medicina/organização & administração , Humanos , Internato e Residência/organização & administração , Licenciamento/normas , Mentores , Estudos de Casos Organizacionais , Aprendizagem Baseada em Problemas/métodos , Aprendizagem Baseada em Problemas/normas , Desenvolvimento de Programas/métodos , Desenvolvimento de Programas/normas , South Carolina , Estados Unidos
9.
NMR Biomed ; 27(8): 948-57, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24890981

RESUMO

The cuprizone mouse model is well established for studying the processes of both demyelination and remyelination in the corpus callosum, and it has been utilized together with diffusion tensor imaging (DTI) to investigate myelin and axonal pathology. Although some underlying morphological mechanisms contributing to the changes in diffusion tensor (DT) metrics have been identified, the understanding of specific associations between histology and diffusion measures remains limited. Diffusional kurtosis imaging (DKI) is an extension of DTI that provides metrics of diffusional non-Gaussianity, for which an associated white matter modeling (WMM) method has been developed. The main goal of the present study was to quantitatively assess the relationships between diffusion measures and histological measures in the mouse model of cuprizone-induced corpus callosum demyelination. The diffusional kurtosis (DK) and WMM metrics were found to provide additional information that enhances the sensitivity to detect the morphological heterogeneity in the chronic phase of the disease process in the rostral segment of the corpus callosum. Specifically, in the rostral segment, axonal water fraction (d = 2.6; p < 0.0001), radial kurtosis (d = 2.0; p = 0.001) and mean kurtosis (d = 1.5; p = 0.005) showed the most sensitivity between groups with respect to yielding statistically significant p values and high Cohen's d values. These results demonstrate the ability of DK and WMM metrics to detect white mater changes and inflammatory processes associated with cuprizone-induced demyelination. They also validate, in part, the application of these new WMM metrics for studying neurological diseases, as well as helping to elucidate their biophysical meaning.


Assuntos
Corpo Caloso/patologia , Doenças Desmielinizantes/patologia , Imagem de Tensor de Difusão , Substância Branca/patologia , Animais , Cuprizona , Doenças Desmielinizantes/induzido quimicamente , Difusão , Masculino , Camundongos Endogâmicos C57BL , Estatísticas não Paramétricas
10.
Abdom Radiol (NY) ; 49(6): 2049-2059, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38517545

RESUMO

PURPOSE: To evaluate quantitative and qualitative spermatic cord CT abnormalities and presence of unilateral or bilateral symptomatic scrotal pathology (SSP) at ultrasound. METHODS: This retrospective study included 122 male patients (mean age 47.8 years) undergoing scrotal ultrasound within 24 h of contrast-enhanced CT (n = 85), non-contrast CT (NECT, n = 32) or CT-Urogram (n = 5). CECT quantitative analysis assessed differential cord enhancement using maximum Hounsfield unit measurements. Three fellowship trained body radiologists independently assessed qualitative cord abnormalities for both CECT and NECT. Qualitative and quantitative findings were compared with the presence of SSP. Reader performance, interobserver agreement and reader confidence were assessed for NECT and CECT. Quantitative cutoff points were identified which maximized accuracy, specificity, negative predictive value, and other measures. RESULTS: SSP was present in 36/122 patients (29.5%). Positive cases were unilateral in 30 (83.3%) and bilateral in 6 (16.6%). At quantitative assessment, 25% differential cord enhancement had the highest diagnostic accuracy (88.9%), with 90.5% positive predictive value, 88.4% negative predictive value, 96.8% specificity, and 70.4% sensitivity. At qualitative evaluation, CECT reader performance was excellent (aggregate AUC = 0.86; P < .001); NECT was poorly discriminatory, although remained significant (aggregate AUC = 0.67; P = .002). Readers had significantly higher confidence levels with CECT (P < .001). Qualitative inter-observer agreement was high for both CECT and NECT (ICC = 0.981 and 0.963, respectively). CONCLUSION: Simple quantitative assessment of differential cord enhancement is highly accurate and specific for SSP at CECT. Qualitative abnormalities at CECT and NECT are also both predictors of SSP, however, CECT significantly out-performs non-contrast exams.


Assuntos
Meios de Contraste , Escroto , Sensibilidade e Especificidade , Cordão Espermático , Tomografia Computadorizada por Raios X , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Escroto/diagnóstico por imagem , Cordão Espermático/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Adulto , Valor Preditivo dos Testes , Ultrassonografia/métodos , Idoso de 80 Anos ou mais , Doenças dos Genitais Masculinos/diagnóstico por imagem , Adolescente
11.
Radiology ; 269(3): 810-5, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24046441

RESUMO

PURPOSE: To determine whether ownership of magnetic resonance (MR) imaging equipment by ordering physicians affects the likelihood of positive findings at MR imaging of the knee and to evaluate rates of knee abnormalities seen at MR imaging as a metric for comparison of utilization. MATERIALS AND METHODS: The institutional review board approved this retrospective HIPAA-compliant study and waived the need for informed consent. A retrospective review was performed of consecutive diagnostic MR images of the knee interpreted by one radiology practice between January and April 2009 for patients who had been referred by two separate physician groups serving the same geographic community: one with financial interest (FI) in the MR imaging equipment used and one with no FI (NFI) in the MR imaging equipment used. The percentage of examinations with negative results was tabulated for both groups, and the relative frequency of each abnormality subtype was calculated among the studies with positive findings in each group. To examine frequency differences among groups, χ(2) tests were used, and to examine mean differences among groups, t tests were used. RESULTS: Of 700 examinations, 205 had negative results (117 of 350 in the FI group and 88 of 350 in the NFI group, P = .016). Among the examinations with positive results, the mean total number of positive abnormality subtypes per image did not significantly differ between groups: 1.52 for the FI group and 1.53 for the NFI group (P = .96). CONCLUSION: MR images of the knee among patients referred by the FI group were significantly more likely to be negative than those among patients referred by the NFI group. Frequency of abnormality subtype and distribution among examinations with positive results suggests a highly similar distribution and severity of abnormalities between the two patient groups.


Assuntos
Joelho/patologia , Imageamento por Ressonância Magnética/estatística & dados numéricos , Autorreferência Médica , Padrões de Prática Médica/estatística & dados numéricos , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/instrumentação , Masculino , Propriedade , Estudos Retrospectivos , Revisão da Utilização de Recursos de Saúde
12.
J Alzheimers Dis ; 96(4): 1827-1836, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38007644

RESUMO

BACKGROUND: Neuropsychiatric symptoms (NPS) carry an increased risk of progression from mild cognitive impairment (MCI) to Alzheimer's disease (AD). There is a need to understand how to integrate NPS into the paradigm outlined in the 2018 NIA-AA Research Framework. OBJECTIVE: To evaluate a prediction model of MCI-AD progression using a collection of variables, including NPS, cognitive testing, apolipoprotein E4 status (APOE4), imaging and laboratory AD biomarkers. METHODS: Of 300 elderly subjects, 219 had stable MCI and 81 MCI-AD progression over a 5-year follow-up. NPS were measured using the Neuropsychiatric Inventory (NPI). A multivariate Cox Proportional Hazards Regression Analysis assessed the effects of APOE4, baseline NPI, baseline CSF amyloid-ß, phosphorylated and total tau, baseline AD-signature MRI biomarker, baseline memory and executive function on MCI-AD progression. RESULTS: 27% progressed to dementia (median follow-up = 43 months). NPS were found in stable MCI (62.6%) and MCI-AD converters (70.3%). The Cox model exhibited a good fit (p < 0.001), and NPS (HR = 1.033, p = 0.027), phosphorylated tau (HR = 1.011, p = 0.025), total tau (HR = 1.005, p = 0.024), AD-signature MRI biomarker (HR = 0.111, p = 0.002), executive function (HR = 0.727, p = 0.045), and memory performance (HR = 0.387, p < 0.001) were significantly associated with dementia. CONCLUSIONS: NPS may inform dementia risk assessment in conjunction with cognitive testing and imaging and laboratory AD biomarkers. NPS is independently associated with the risk of MCI-dementia progression, over and beyond the contributions of CSF biomarkers.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Idoso , Doença de Alzheimer/diagnóstico por imagem , Proteínas tau , Apolipoproteína E4 , Progressão da Doença , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Biomarcadores , Peptídeos beta-Amiloides , Fragmentos de Peptídeos
13.
J Cogn Neurosci ; 24(12): 2428-44, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22849402

RESUMO

The degree to which face-specific brain regions are specialized for different kinds of perceptual processing is debated. This study parametrically varied demands on featural, first-order configural, or second-order configural processing of faces and houses in a perceptual matching task to determine the extent to which the process of perceptual differentiation was selective for faces regardless of processing type (domain-specific account), specialized for specific types of perceptual processing regardless of category (process-specific account), engaged in category-optimized processing (i.e., configural face processing or featural house processing), or reflected generalized perceptual differentiation (i.e., differentiation that crosses category and processing type boundaries). ROIs were identified in a separate localizer run or with a similarity regressor in the face-matching runs. The predominant principle accounting for fMRI signal modulation in most regions was generalized perceptual differentiation. Nearly all regions showed perceptual differentiation for both faces and houses for more than one processing type, even if the region was identified as face-preferential in the localizer run. Consistent with process specificity, some regions showed perceptual differentiation for first-order processing of faces and houses (right fusiform face area and occipito-temporal cortex and right lateral occipital complex), but not for featural or second-order processing. Somewhat consistent with domain specificity, the right inferior frontal gyrus showed perceptual differentiation only for faces in the featural matching task. The present findings demonstrate that the majority of regions involved in perceptual differentiation of faces are also involved in differentiation of other visually homogenous categories.


Assuntos
Encéfalo/fisiologia , Face , Percepção Visual/fisiologia , Adolescente , Adulto , Análise de Variância , Comportamento/fisiologia , Mapeamento Encefálico , Interpretação Estatística de Dados , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Adulto Jovem
14.
Neuroimage ; 63(3): 1223-36, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22906788

RESUMO

Greater expertise for faces in adults than in children may be achieved by a dynamic interplay of functional segregation and integration of brain regions throughout development. The present study examined developmental changes in face network functional connectivity in children (5-12 years) and adults (18-43 years) during face-viewing using a graph-theory approach. A face-specific developmental change involved connectivity of the right occipital face area. During childhood, this node increased in strength and within-module clustering based on positive connectivity. These changes reflect an important role of the ROFA in segregation of function during childhood. In addition, strength and diversity of connections within a module that included primary visual areas (left and right calcarine) and limbic regions (left hippocampus and right inferior orbitofrontal cortex) increased from childhood to adulthood, reflecting increased visuo-limbic integration. This integration was pronounced for faces but also emerged for natural objects. Taken together, the primary face-specific developmental changes involved segregation of a posterior visual module during childhood, possibly implicated in early stage perceptual face processing, and greater integration of visuo-limbic connections from childhood to adulthood, which may reflect processing related to development of perceptual expertise for individuation of faces and other visually homogenous categories.


Assuntos
Mapeamento Encefálico , Encéfalo/crescimento & desenvolvimento , Encéfalo/fisiologia , Vias Neurais/crescimento & desenvolvimento , Vias Neurais/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Adolescente , Adulto , Criança , Pré-Escolar , Face , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
15.
Cureus ; 14(11): e31897, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36579217

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has disrupted the world since 2019, causing significant morbidity and mortality in developed and developing countries alike. Although substantial resources have been diverted to developing diagnostic, preventative, and treatment measures, disparities in the availability and efficacy of these tools vary across countries. We seek to assess the ability of commercial artificial intelligence (AI) technology to diagnose COVID-19 by analyzing chest radiographs. MATERIALS AND METHODS: Chest radiographs taken from symptomatic patients within two days of polymerase chain reaction (PCR) tests were assessed for COVID-19 infection by board-certified radiologists and commercially available AI software. Sixty patients with negative and 60 with positive COVID reverse transcription-polymerase chain reaction (RT-PCR) tests were chosen. Results were compared against results of the PCR test for accuracy and statistically analyzed by receiver operating characteristic (ROC) curves along with area under the curve (AUC) values. RESULTS: A total of 120 chest radiographs (60 positive and 60 negative RT-PCR tests) radiographs were analyzed. The AI software performed significantly better than chance (p = 0.001) and did not differ significantly from the radiologist ROC curve (p = 0.78). CONCLUSION: Commercially available AI software was not inferior compared with trained radiologists in accurately identifying COVID-19 cases by analyzing radiographs. While RT-PCR testing remains the standard, current advances in AI help correctly analyze chest radiographs to diagnose COVID-19 infection.

16.
Aging Brain ; 1: 100017, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-36911514

RESUMO

An 11-25% increase in total ventricular volume has been documented in astronauts following spaceflight on the ISS. Given the approximately 2-year time interval between pre- and post-flight MRI, it is unknown if ventricular enlargement simply reflects normal aging or is unique to spaceflight exposure. Therefore, we compared percent ventricular volume change per year (PVVC/yr) documented on pre- to post-flight MRI in a group of NASA ISS astronauts (n = 18, 16.7% women, mean age (SD) 48.43 (4.35) years) with two groups who underwent longitudinal MRI: (1.) healthy age- and sex-matched adults (n = 18, 16.7% women, mean age (SD) 51.26 (3.88) years), and (2.) healthy older adults (n = 79, 16.5% women, mean age (SD) 73.26 (5.34) years). The astronauts, who underwent a mean (SD) 173.4 (51.3) days in spaceflight, showed a greater increase in PVVC/yr than the control (6.86 vs 2.23%, respectively, p < .001) and older adult (4.18%, p = 0.04) groups. These results highlight that on top of physiologically ventricular volume changes due to normal aging, NASA astronauts undergoing ISS missions experience an additional 4.63% PVVC/yr and underscore the need to perform post-flight follow-up scans to determine the time course of PVVC in astronauts over time back on Earth along with monitoring to determine if the PVVC is ultimately clinically relevant. One sentence summary: NASA astronauts who were exposed to prolonged spaceflight experienced an annual rate of ventricular expansion more than three times that expected from normal aging.

17.
JAMA Netw Open ; 4(10): e2131465, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34705011

RESUMO

Importance: Spaceflight-associated neuro-ocular syndrome (SANS) occurs in 40% to 60% of National Aeronautics and Space Administration (NASA) International Space Station (ISS) astronauts who present postflight with ophthalmological findings and elevated intracranial pressure. The etiology of SANS is unknown; it is hypothesized that venous outflow congestion from the head and neck occurs because of microgravity, which is supported by the finding of internal jugular vein stagnant flow and thrombosis in some astronauts, but the impact on intracranial dural venous sinus structures remains unknown. Objectives: To clarify the potential risk of retrograde extension of clot intracranially among astronauts with internal jugular venous thrombosis by evaluating intracranial venous structures following spaceflight and to assess for any association between intracranial venous congestion and SANS. Design, Setting, and Participants: This retrospective cohort study of all NASA astronauts who had undergone magnetic resonance (MR) venography at the time of the study included quantitative and qualitative assessments of the intracranial venous system on preflight and postflight MR venograms. Data were collected a mean (SD) of 525.8 (187.5) days before spaceflight and 2.0 (1.5) days after return to Earth. A semiautomated segmentation of the venogram images was used, which was then compared with a neuroradiologist's assessment. Exposures: A mean (SD) 184.3 (66.0) days of ISS spaceflight missions. Main Outcomes and Measures: Dural venous sinus volumes before and after spaceflight. Results: A total of 12 astronauts (2 [16.67%] women; 10 [83.33%] men), with a mean (SD) age of 47.8 (5.8) years, were included. Overall, 4 astronauts (33.33%) met the diagnostic criteria for SANS. No dural venous sinus thrombosis was detected for any astronaut. Astronauts with SANS had significantly greater median (range) preflight to postflight increases in volume vs astronauts without SANS for all 3 venous sinus structures: superior sagittal sinus (13.40% [8.70% to 17.47%] vs -2.66% [-15.84% to 5.31%,]; P = .004), right transverse/sigmoid sinus (17.15% [7.63% to 30.08%] vs 0.77% [-14.98% to 15.12%]; P = .02), and left transverse/sigmoid sinus (9.40% [5.20% to 15.50%] vs -1.40% [-14.20% to 12.50%]; P = .03). There was a positive correlation between the neuroradiologist's evaluation and the semiautomated method for the superior sagittal sinus (rpb = 0.64; P = .02) and the right transverse/sigmoid sinus (rpb = 0.58; P = .050). Conclusions and Relevance: These findings, in conjunction with the growing body of evidence of abnormal blood flow dynamics during spaceflight, suggest an association between intracranial venous congestion and SANS. Thus, there is an implication that individuals with increased venous sinus compliance may be at increased risk of developing SANS. These findings should be confirmed in a larger astronaut population and may contribute to understanding disorders of intracranial venous outflow on Earth.


Assuntos
Astronautas , Trombose dos Seios Intracranianos , Voo Espacial , Síndrome , Transtornos da Visão , Adulto , Estudos de Coortes , Feminino , Humanos , Hipertensão Intracraniana , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Trombose dos Seios Intracranianos/diagnóstico por imagem , Trombose dos Seios Intracranianos/epidemiologia , Transtornos da Visão/diagnóstico por imagem , Transtornos da Visão/epidemiologia
18.
JAMA Otolaryngol Head Neck Surg ; 146(6): 571-577, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32215610

RESUMO

Importance: Head congestion is one of the most common somatic symptoms experienced by astronauts during spaceflight; however, changes in the opacification of the paranasal sinuses or mastoid air cells in astronauts have not been adequately studied. Objectives: To quantify preflight to postflight changes in the opacification of the paranasal sinuses and mastoid air cells in Space Shuttle astronauts and International Space Station (ISS) astronauts and to assess whether there are differences between the 2 groups of astronauts. Design, Setting, and Participants: This cohort study examined preflight and postflight head magnetic resonance images (MRIs) of 35 astronauts who had participated in either a short-duration (≤30 days) Space Shuttle mission or a long-duration (>30 days) ISS mission and had undergone both preflight and postflight MRI. Images were obtained before and after spaceflight. Images were evaluated by 2 neuroradiologists blinded to which mission each astronaut had flown and to which images were preflight or postflight images. Exposure: Spaceflight on the Space Shuttle or the ISS. Main Outcomes and Measures: Measured outcomes included preflight to postflight changes in Lund-Mackay scores for the paranasal sinuses and in scores grading mastoid effusions. Results: Most astronauts in both the Space Shuttle group (n = 17; 15 men; mean [SD] age at launch, 47.7 [3.1] years) and the ISS group (n = 18; 14 men; mean [SD] age at launch, 48.6 [4.7] years) exhibited either no change or a reduction in paranasal sinus opacification as seen on postflight MRI scans (Space Shuttle group: 6 [35.3%] had no sinus opacification before or after spaceflight, 5 [29.4%] had less sinus opacification after spaceflight, 3 [17.6%] had the same amount of sinus opacification before and after spaceflight, and 3 [17.6%] had increased paranasal sinus opacification after spaceflight; ISS group: 8 [44.4%] had no sinus opacification before or after spaceflight, 4 [22.2%] had less sinus opacification after spaceflight, 1 (5.6%) had the same amount of sinus opacification before and after spaceflight, and 5 [27.8%] had scores consistent with increased paranasal sinus opacification after spaceflight). Long-duration spaceflight (ISS group) was associated with an increased risk of mastoid effusion relative to short-duration spaceflight (relative risk, 4.72; 95% CI, 1.2-18.5). Images were obtained a mean (SD) 287.5 (208.6) days (range, 18-627 days) prior to and 6.8 (5.8) days (range, 1-20 days) after spaceflight. Astronauts had undergone either a mean (SD) of 13.6 (1.6) days of spaceflight on the Space Shuttle (17 astronauts) or 164.8 (18.9) days on the ISS (18 astronauts). Conclusions and Relevance: This study found that exposure to spaceflight conditions on the ISS is associated with an increased likelihood for the formation of mastoid effusions. There was no association between exposure to spaceflight conditions and changes in paranasal sinus opacification. The limitations of this study include lack of information concerning medical history and mission-specific operational experience for individual astronauts. Further studies are indicated to determine the cause and composition of the mastoid effusions.


Assuntos
Processo Mastoide/citologia , Mucosa Nasal/fisiologia , Seios Paranasais/fisiologia , Voo Espacial , Tuba Auditiva/fisiopatologia , Feminino , Humanos , Hiperemia/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Processo Mastoide/diagnóstico por imagem , Pessoa de Meia-Idade , Seios Paranasais/diagnóstico por imagem , Seios Paranasais/fisiopatologia , Pressão , Fatores de Tempo
20.
Gerontol Geriatr Med ; 2: 2333721415625688, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28138486

RESUMO

There are a number of factors that influence compliance with prescribed plans of care. However, there remains a need to identify the collective source health, behavioral, and social constructs have on treatment satisfaction. This study aimed to identify indicators of pain treatment satisfaction among older adults receiving outpatient treatment from a comprehensive cancer center in the southeast region of the United States. Data included a sample of 149 Black and White patients diagnosed with cancer, with the majority being White (85%) and female (57%). Patients were surveyed on questions assessing pain treatment satisfaction, pain severity, and additional social characteristics. A series of multivariate models were specified, whereby patients reporting multiple chronic conditions, poor communication, and perceived discrimination were less satisfied with treatment. Positive communication, higher self-efficacy, and fewer perceived discriminatory acts were significant among the female patients only. These findings suggest the need to develop clinical models that assess how these factors influence the degree of treatment satisfaction, while providing a comprehensive mechanism by which to service the long-term needs of older adults.

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