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1.
BMC Psychol ; 9(1): 133, 2021 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-34479637

RESUMO

BACKGROUND: This study investigated the impact of semantic relevance on the ability to comprehend the appearance and function of a product, as presented in images. METHODS: The images used the constructs of Simile, Metaphor and Analogy to correspond to congruent, related and incongruent semantic structures, and measured the amplitude of Event-Related Potentials (ERPs) to compare these images with Landscape images. Sixteen participants with design-related educational backgrounds were invited to join in the ERP experiment. RESULTS: The results found that the image depicting the Metaphor showed a stronger N600 amplitude in the right anterior region of the brain than the Landscape image and the Analogy image induced a stronger N600 effect in the left anterior and right anterior part of the brain than the Landscape image. However, the Simile image did not trigger the N600. The N600 was triggered when the meaning of the Metaphor and Analogy being presented could not be understood. This indicates that a greater processing effort to comprehend them than was required for Simile. Analogy has a wider N600 distribution than Metaphor in the anterior area, suggesting that Analogy would require higher-level thinking processes and more complex semantic processing mechanisms than Metaphor. CONCLUSIONS: The N600 implicated that an assessment method to detect the semantic relationship between appearance and function of a product would assist in determining whether a symbol was suitable to be associated with a product.


Assuntos
Mapeamento Encefálico , Semântica , Encéfalo/diagnóstico por imagem , Compreensão , Eletroencefalografia , Potenciais Evocados , Humanos , Metáfora
2.
Neurol India ; 69(4): 1010-1013, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34507431

RESUMO

Rasmussen's encephalopathy (RE) is an uncommon neurological disease of inflammatory origin which is characterized by intractable focal epilepsy, progressive limb weakness, and cognitive deterioration. RE presenting as movement disorder like hemidystonia or hemichorea is a rare occurrence. The duration of prodromal stage of RE is usually in weeks or months. Prolonged prodromal stage like in years is rarely reported. Magnetic resonance imaging (MRI) is a good biomarker in RE and it also suggests the sequential progression of disease. Here we report two cases of RE, one presenting with hemidystonia and other case with unusually prolonged prodromal stage duration of 7 years. In spite of severe hemi-atrophy of brain in second case response to immunomodulators was dramatic.


Assuntos
Encefalite , Epilepsias Parciais , Atrofia/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encefalite/diagnóstico por imagem , Encefalite/patologia , Humanos , Imageamento por Ressonância Magnética
3.
Neurol India ; 69(4): 1027-1031, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34507436

RESUMO

Cerebral phaeohyphomycosis is a rare but serious fungal infection of the central nervous system caused by dematiaceous septate fungi characterized by the presence of melanin-like pigment within the cell wall that is a pale brown to black. It is associated with poor prognosis despite aggressive treatment. We report a previously well 3-year boy with cerebral phaeohyphomycosis who had subacute meningoencephalitic presentation with refractory raised intracranial pressure and had fatal outcomes. The diagnosis was confirmed by histopathological examination of brain tissue obtained by brain biopsy.


Assuntos
Feoifomicose Cerebral , Meningoencefalite , Micoses , Encéfalo/diagnóstico por imagem , Criança , Humanos , Masculino
4.
Sensors (Basel) ; 21(17)2021 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-34502710

RESUMO

Autism spectrum disorder (ASD) is a neurodegenerative disorder characterized by lingual and social disabilities. The autism diagnostic observation schedule is the current gold standard for ASD diagnosis. Developing objective computer aided technologies for ASD diagnosis with the utilization of brain imaging modalities and machine learning is one of main tracks in current studies to understand autism. Task-based fMRI demonstrates the functional activation in the brain by measuring blood oxygen level-dependent (BOLD) variations in response to certain tasks. It is believed to hold discriminant features for autism. A novel computer aided diagnosis (CAD) framework is proposed to classify 50 ASD and 50 typically developed toddlers with the adoption of CNN deep networks. The CAD system includes both local and global diagnosis in a response to speech task. Spatial dimensionality reduction with region of interest selection and clustering has been utilized. In addition, the proposed framework performs discriminant feature extraction with continuous wavelet transform. Local diagnosis on cingulate gyri, superior temporal gyrus, primary auditory cortex and angular gyrus achieves accuracies ranging between 71% and 80% with a four-fold cross validation technique. The fused global diagnosis achieves an accuracy of 86% with 82% sensitivity, 92% specificity. A brain map indicating ASD severity level for each brain area is created, which contributes to personalized diagnosis and treatment plans.


Assuntos
Transtorno do Espectro Autista , Imageamento por Ressonância Magnética , Transtorno do Espectro Autista/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Humanos , Análise de Ondaletas
5.
Croat Med J ; 62(4): 318-327, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34472734

RESUMO

AIMS: To report the outcomes of robot-assisted brain biopsies performed using a novel RONNA G4 system. The system was developed by a research group from the Faculty of Mechanical Engineering and Naval Architecture and a team of neurosurgeons from Dubrava University Hospital, University of Zagreb School of Medicine. METHODS: This prospective study included 49 biopsies analyzed during one year: 23 robotic frameless and 26 frame-based Leksell stereotactic biopsies. We analyzed the presenting symptoms, tumor range and location, postoperative complications, pathohistological diagnosis, diagnostic yield, as well as operation and hospitalization duration. The target point error was calculated to assess the accuracy of the RONNA system. RESULTS: No postoperative mortality, morbidity, or infections were observed. In the frameless robotic biopsy group, only one pathohistological diagnosis was inconclusive. Therefore, the diagnostic yield was 95.6% (22/23), similar to that of the framebased Leksell stereotactic biopsy group (95.1% or 25/26). The average target point error in the frameless robotic biopsy group was 2.15±1.22 mm (range 0.39-5.85). CONCLUSION: The RONNA G4 robotic system is a safe and accurate tool for brain biopsy, although further research warrants a larger patient sample, comparison with other robotic systems, and a systematic analysis of the entry and target point errors.


Assuntos
Neoplasias Encefálicas , Procedimentos Cirúrgicos Robóticos , Robótica , Biópsia , Encéfalo/diagnóstico por imagem , Humanos , Neuronavegação , Estudos Prospectivos , Técnicas Estereotáxicas
6.
World J Gastroenterol ; 27(30): 4999-5018, 2021 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-34497431

RESUMO

Metabolic associated fatty liver disease (MAFLD), formerly named "nonalcoholic fatty liver disease" occurs in about one-third of the general population of developed countries worldwide and behaves as a major morbidity and mortality risk factor for major causes of death, such as cardiovascular, digestive, metabolic, neoplastic and neuro-degenerative diseases. However, progression of MAFLD and its associated systemic complications occur almost invariably in patients who experience the additional burden of intrahepatic and/or systemic inflammation, which acts as disease accelerator. Our review is focused on the new knowledge about the brain-gut-liver axis in the context of metabolic dysregulations associated with fatty liver, where insulin resistance has been assumed to play an important role. Special emphasis has been given to digital imaging studies and in particular to positron emission tomography, as it represents a unique opportunity for the noninvasive in vivo study of tissue metabolism. An exhaustive revision of targeted animal models is also provided in order to clarify what the available preclinical evidence suggests for the causal interactions between fatty liver, dysregulated endogenous glucose production and insulin resistance.


Assuntos
Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Animais , Encéfalo/diagnóstico por imagem , Glucose , Humanos , Fígado/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem
7.
BMC Geriatr ; 21(1): 475, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34465287

RESUMO

BACKGROUND: Grip strength is an indicator of physical function with potential predictive value for health in ageing populations. We assessed whether trends in grip strength from midlife predicted later-life brain health and cognition. METHODS: 446 participants in an ongoing British birth cohort study, the National Survey of Health and Development (NSHD), had their maximum grip strength measured at ages 53, 60-64, and 69, and subsequently underwent neuroimaging as part of a neuroscience sub-study, referred to as "Insight 46", at age 69-71. A group-based trajectory model identified latent groups of individuals in the whole NSHD cohort with below- or above-average grip strength over time, plus a reference group. Group assignment, plus standardised grip strength levels and change from midlife were each related to measures of whole-brain volume (WBV) and white matter hyperintensity volume (WMHV), plus several cognitive tests. Models were adjusted for sex, body size, head size (where appropriate), sociodemographics, and behavioural and vascular risk factors. RESULTS: Lower grip strength from midlife was associated with smaller WBV and lower matrix reasoning scores at age 69-71, with findings consistent between analysis of individual time points and analysis of trajectory groups. There was little evidence of an association between grip strength and other cognitive test scores. Although greater declines in grip strength showed a weak association with higher WMHV at age 69-71, trends in the opposite direction were seen at individual time points with higher grip strength at ages 60-64, and 69 associated with higher WMHV. CONCLUSIONS: This study provides preliminary evidence that maximum grip strength may have value in predicting brain health. Future work should assess to what extent age-related declines in grip strength from midlife reflect concurrent changes in brain structure.


Assuntos
Encéfalo , Cognição , Idoso , Envelhecimento , Encéfalo/diagnóstico por imagem , Estudos de Coortes , Força da Mão , Humanos
8.
Nutrients ; 13(8)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34444644

RESUMO

Polar lipids, which are found in human milk, serve essential functions within biological membranes, hence their importance in brain development and cognition. Therefore, we aimed to evaluate the longitudinal effects on brain macrostructural and microstructural development and recognition memory of early-life polar lipid supplementation using the translational pig model. Twenty-eight intact (i.e., not castrated) male pigs were provided either a control diet (n = 14) or the control diet supplemented with polar lipids (n = 14) from postnatal day 2 until postnatal week 4. After postnatal week 4, all animals were provided the same nutritionally-adequate diets until postnatal week 24. Pigs underwent magnetic resonance imaging at 8 longitudinal time-points to model brain macrostructural and microstructural developmental trajectories. The novel object recognition task was implemented at postnatal weeks 4 and 8 to evaluate recognition memory. Subtle differences were observed between groups in hippocampal absolute brain volumes and fractional anisotropy, and no differences in myelin water fraction developmental patterns were noted. Behavioral outcomes did not differ in recognition memory, and only minimal differences were observed in exploratory behaviors. Our findings suggest that early-life dietary supplementation of polar lipids has limited effect on brain developmental patterns, object recognition memory, and exploratory behaviors.


Assuntos
Encéfalo/crescimento & desenvolvimento , Gorduras na Dieta/administração & dosagem , Suplementos Nutricionais , Lipídeos/administração & dosagem , Reconhecimento Psicológico , Animais , Comportamento Animal , Encéfalo/diagnóstico por imagem , Comportamento Exploratório , Imageamento por Ressonância Magnética , Masculino , Suínos , Ganho de Peso
9.
Neuroscience ; 472: 103-115, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34364954

RESUMO

The global fractional anisotropy (gFA) is a structural marker of white matter myelination and integrity. Previous studies already evidenced that aging-related reduced integrity of specific white matter tracts is associated with decreased functional connectivity in several hubs. However, the correlations between gFA and functional brain connectivity remain unknown. In this cross-sectional study, we analyzed structural and functional MR datasets of 79 healthy participants from the Leipzig Study for Mind-Body-Emotion Interactions. DTI model-based method was used to quantify gFA values. We tested associations between gFA, age, and gender. The fractional amplitude of low-frequency fluctuations (fALFF) and ROI-to-ROI connectivity were analyzed in a regression model for evaluating the effects of gFA on brain activity and networking, respectively. A negative correlation was found between gFA and age (ρ = -0.343; p = 0.002). No statistically significant correlation as found between gFA and gender (p = 0.229). Higher values of gFA were associated with increased brain regional activity, including areas of the default mode network. There was a higher degree of correlation between some regions, particularly those that conform to the limbic system. Our study demonstrates that gFA influences regional neural activity and brain networking on resting, particularly the limbic system.


Assuntos
Encéfalo , Substância Branca , Anisotropia , Encéfalo/diagnóstico por imagem , Estudos Transversais , Voluntários Saudáveis , Humanos , Imageamento por Ressonância Magnética , Substância Branca/diagnóstico por imagem
10.
Sci Transl Med ; 13(607)2021 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-34408078

RESUMO

Dystonias are a group of chronic movement-disabling disorders for which highly effective oral medications or disease-modifying therapies are lacking. The most effective treatments require invasive procedures such as deep brain stimulation. In this study, we used a high-throughput assay based on a monogenic form of dystonia, DYT1 (DYT-TOR1A), to screen a library of compounds approved for use in humans, the NCATS Pharmaceutical Collection (NPC; 2816 compounds), and identify drugs able to correct mislocalization of the disease-causing protein variant, ∆E302/3 hTorsinA. The HIV protease inhibitor, ritonavir, was among 18 compounds found to normalize hTorsinA mislocalization. Using a DYT1 knock-in mouse model to test efficacy on brain pathologies, we found that ritonavir restored multiple brain abnormalities across development. Ritonavir acutely corrected striatal cholinergic interneuron physiology in the mature brain and yielded sustained correction of diffusion tensor magnetic resonance imaging signals when delivered during a discrete early developmental window. Mechanistically, we found that, across the family of HIV protease inhibitors, efficacy correlated with integrated stress response activation. These preclinical results identify ritonavir as a drug candidate for dystonia with disease-modifying potential.


Assuntos
Distonia , Inibidores da Protease de HIV , Animais , Encéfalo/diagnóstico por imagem , Distonia/tratamento farmacológico , Camundongos , Chaperonas Moleculares , Fenótipo , Ritonavir
11.
Nat Commun ; 12(1): 4894, 2021 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385454

RESUMO

White matter structural connections are likely to support flow of functional activation or functional connectivity. While the relationship between structural and functional connectivity profiles, here called SC-FC coupling, has been studied on a whole-brain, global level, few studies have investigated this relationship at a regional scale. Here we quantify regional SC-FC coupling in healthy young adults using diffusion-weighted MRI and resting-state functional MRI data from the Human Connectome Project and study how SC-FC coupling may be heritable and varies between individuals. We show that regional SC-FC coupling strength varies widely across brain regions, but was strongest in highly structurally connected visual and subcortical areas. We also show interindividual regional differences based on age, sex and composite cognitive scores, and that SC-FC coupling was highly heritable within certain networks. These results suggest regional structure-function coupling is an idiosyncratic feature of brain organisation that may be influenced by genetic factors.


Assuntos
Algoritmos , Encéfalo/fisiologia , Conectoma/métodos , Modelos Neurológicos , Rede Nervosa/fisiologia , Adulto , Encéfalo/anatomia & histologia , Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/anatomia & histologia , Rede Nervosa/diagnóstico por imagem , Adulto Jovem
13.
J Headache Pain ; 22(1): 102, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34454429

RESUMO

BACKGROUND: In the past decades a plethora of studies has been conducted to explore resting-state functional connectivity (RS-FC) of the brain networks in migraine with conflicting results probably due to the variability and susceptibility of signal fluctuations across the course of RS-FC scan. On the other hand, the structural substrates enabling the functional communications among the brain connectome, characterized by higher stability and reproducibility, have not been widely investigated in migraine by means of graph analysis approach. We hypothesize a rearrangement of the brain connectome with an increase of both strength and density of connections between cortical areas specifically involved in pain perception, processing and modulation in migraine patients. Moreover, such connectome rearrangement, inducing an imbalance between the competing parameters of network efficiency and segregation, may underpin a mismatch between energy resources and demand representing the neuronal correlate of the energetically dysfunctional migraine brain. METHODS: We investigated, using diffusion-weighted MRI imaging tractography-based graph analysis, the graph-topological indices of the brain "connectome", a set of grey matter regions (nodes) structurally connected by white matter paths (edges) in 94 patients with migraine without aura compared to 91 healthy controls. RESULTS: We observed in migraine patients compared to healthy controls: i) higher local and global network efficiency (p < 0.001) and ii) higher local and global clustering coefficient (p < 0.001). Moreover, we found changes in the hubs topology in migraine patients with: i) posterior cingulate cortex and inferior parietal lobule (encompassing the so-called neurolimbic-pain network) assuming the hub role and ii) fronto-orbital cortex, involved in emotional aspects, and visual areas, involved in migraine pathophysiology, losing the hub role. Finally, we found higher connection (edges) probability between cortical nodes involved in pain perception and modulation as well as in cognitive and affective attribution of pain experiences, in migraine patients when compared to healthy controls (p < 0.001). No correlations were found between imaging and clinical parameters of disease severity. CONCLUSION: The imbalance between the need of investing resources to promote network efficiency and the need of minimizing the metabolic cost of wiring probably represents the mechanism underlying migraine patients' susceptibility to triggers. Such changes in connectome topography suggest an intriguing pathophysiological model of migraine as brain "connectopathy".


Assuntos
Conectoma , Transtornos de Enxaqueca , Encéfalo/diagnóstico por imagem , Substância Cinzenta , Humanos , Transtornos de Enxaqueca/diagnóstico por imagem , Reprodutibilidade dos Testes
14.
Zh Vopr Neirokhir Im N N Burdenko ; 85(4): 103-110, 2021.
Artigo em Russo | MEDLINE | ID: mdl-34463457

RESUMO

This review is devoted to various techniques for reduction of brain damage during retraction. Searching for reports was carried out in Russian and English languages using the PubMed database (n=721) without restrictions on language, date and study design according to the following keywords: «brain retraction injury¼, «spatula brain retractors¼, «tubular brain retractors¼, «retractorless neurosurgery¼. Primary screening and exclusion of duplicate manuscripts allowed us to single out the main group of articles (n=121). Some reports were excluded due to non-compliance with inclusion criteria (no description of methods, few references and insufficient data). The final list included 32 studies which were represented by cohort studies, retrospective analyses of surgical interventions, as well as experimental and laboratory studies. Small number of publications did not allow us to obtain unambiguous conclusions. Further research is required to reduce brain retraction trauma.


Assuntos
Lesões Encefálicas , Procedimentos Neurocirúrgicos , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Humanos , Estudos Retrospectivos , Instrumentos Cirúrgicos
15.
Comput Intell Neurosci ; 2021: 6660866, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34422034

RESUMO

Machine learning methods have been successfully applied to neuroimaging signals, one of which is to decode specific task states from functional magnetic resonance imaging (fMRI) data. In this paper, we propose a model that simultaneously utilizes characteristics of both spatial and temporal sequential information of fMRI data with deep neural networks to classify the fMRI task states. We designed a convolution network module and a recurrent network module to extract the spatial and temporal features of fMRI data, respectively. In particular, we also add the attention mechanism to the recurrent network module, which more effectively highlights the brain activation state at the moment of reaction. We evaluated the model using task-evoked fMRI data from the Human Connectome Project (HCP) dataset, the classification accuracy got 94.31%, and the experimental results have shown that the model can effectively distinguish the brain states under different task stimuli.


Assuntos
Conectoma , Aprendizado Profundo , Encéfalo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Redes Neurais de Computação
16.
Nat Commun ; 12(1): 4830, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376663

RESUMO

Choice-relevant brain regions in prefrontal cortex may progressively transform information about options into choices. Here, we examine responses of neurons in four regions of the medial prefrontal cortex as macaques performed two-option risky choices. All four regions encode economic variables in similar proportions and show similar putative signatures of key choice-related computations. We provide evidence to support a gradient of function that proceeds from areas 14 to 25 to 32 to 24. Specifically, we show that decodability of twelve distinct task variables increases along that path, consistent with the idea that regions that are higher in the anatomical hierarchy make choice-relevant variables more separable. We also show progressively longer intrinsic timescales in the same series. Together these results highlight the importance of the medial wall in choice, endorse a specific gradient-based organization, and argue against a modular functional neuroanatomy of choice.


Assuntos
Comportamento de Escolha/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Córtex Pré-Frontal/fisiologia , Potenciais de Ação/fisiologia , Algoritmos , Animais , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Mapeamento Encefálico , Imageamento por Ressonância Magnética/métodos , Modelos Neurológicos , Córtex Pré-Frontal/citologia
17.
Biomed Res Int ; 2021: 2013371, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34435041

RESUMO

Background: This study was aimed at revealing neuroimaging findings in COVID-19 patients and at discussing their relationship with epidemiological data and some laboratory parameters. Materials and Method. This study included 436 cases of COVID-19 and 40 cases of non-COVID-19 acute/subacute thromboembolism who underwent at least one neuroimaging procedure due to neurological symptoms between April 2020 and December 2020. The group of COVID-19-positive acute/subacute thromboembolism cases was compared with both the group of normal brain imaging cases and the non-COVID-19 acute/subacute thromboembolism group in terms of demographic data and laboratory parameters. Results: When the acute/subacute thromboembolism group and neuroimaging findings were compared in terms of negative group, presence of comorbid disease, D-dimer level, and lymphocyte count in COVID-19 patients, a statistically significant difference was found (p = 0.047, 0.014, and <0.001, respectively). COVID-19-positive and COVID-19-negative acute/subacute thromboembolism cases that were compared in terms of gender, neuroimaging reason, C-reactive protein, D-dimer level and lymphocyte count, a statistically significant difference was found (p = 0.003, <0.001, 0.005, 0.02, and <0.001, respectively). Conclusion: Acute thromboembolic events are common in patients with COVID-19 due to a potentially increased procoagulant process. Neurological evaluation and, if necessary, detailed neuroimaging should be performed, especially in cases with high D-dimer levels.


Assuntos
Teste para COVID-19/métodos , COVID-19/diagnóstico por imagem , Neuroimagem/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , COVID-19/sangue , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Lobo Occipital/diagnóstico por imagem , Estudos Retrospectivos , SARS-CoV-2/isolamento & purificação , Tromboembolia/sangue , Tromboembolia/diagnóstico por imagem , Adulto Jovem
18.
Medicina (Kaunas) ; 57(8)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34441042

RESUMO

Background and objective: This study was conducted to assess the prevalence and clinical implications of parotid lesions detected incidentally during brain magnetic resonance imaging (MRI) examination. Materials and Methods: Between February 2016 and February 2021, we identified 86 lesions in the brain MRI reports of 84 patients that contained the words "parotid gland" or "PG". Of these, we finally included 49 lesions involving 45 patients following histopathological confirmation. Results: Based on the laboratory, radiological or histopathological findings, the prevalence of incidental parotid lesions was low (1.2%). Among the 45 study patients, 41 (91.1%) had unilateral lesions, and the majority of the lesions were located in the superficial lobe (40/49, 81.6%). The mean size of the parotid lesions was 1.3 cm ± 0.4 cm (range, 0.5 cm-2.8 cm). Of these, 46 parotid lesions (93.9%) were benign, whereas the remaining three lesions were malignant (6.1%). Conclusions: Despite the low prevalence and incidence of malignancy associated with incidental parotid lesions detected on brain MRI, the clinical implications are potentially significant. Therefore, clinical awareness and appropriate imaging work-up of these lesions are important for accurate diagnosis and timely management.


Assuntos
Imageamento por Ressonância Magnética , Glândula Parótida , Encéfalo/diagnóstico por imagem , Humanos , Glândula Parótida/diagnóstico por imagem , Prevalência , Estudos Retrospectivos
19.
Sensors (Basel) ; 21(16)2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34450699

RESUMO

The functional connectivity (FC) patterns of resting-state functional magnetic resonance imaging (rs-fMRI) play an essential role in the development of autism spectrum disorders (ASD) classification models. There are available methods in literature that have used FC patterns as inputs for binary classification models, but the results barely reach an accuracy of 80%. Additionally, the generalizability across multiple sites of the models has not been investigated. Due to the lack of ASD subtypes identification model, the multi-class classification is proposed in the present study. This study aims to develop automated identification of autism spectrum disorder (ASD) subtypes using convolutional neural networks (CNN) using dynamic FC as its inputs. The rs-fMRI dataset used in this study consists of 144 individuals from 8 independent sites, labeled based on three ASD subtypes, namely autistic disorder (ASD), Asperger's disorder (APD), and pervasive developmental disorder not otherwise specified (PDD-NOS). The blood-oxygen-level-dependent (BOLD) signals from 116 brain nodes of automated anatomical labeling (AAL) atlas are used, where the top-ranked node is determined based on one-way analysis of variance (ANOVA) of the power spectral density (PSD) values. Based on the statistical analysis of the PSD values of 3-level ASD and normal control (NC), putamen_R is obtained as the top-ranked node and used for the wavelet coherence computation. With good resolution in time and frequency domain, scalograms of wavelet coherence between the top-ranked node and the rest of the nodes are used as dynamic FC feature input to the convolutional neural networks (CNN). The dynamic FC patterns of wavelet coherence scalogram represent phase synchronization between the pairs of BOLD signals. Classification algorithms are developed using CNN and the wavelet coherence scalograms for binary and multi-class identification were trained and tested using cross-validation and leave-one-out techniques. Results of binary classification (ASD vs. NC) and multi-class classification (ASD vs. APD vs. PDD-NOS vs. NC) yielded, respectively, 89.8% accuracy and 82.1% macro-average accuracy, respectively. Findings from this study have illustrated the good potential of wavelet coherence technique in representing dynamic FC between brain nodes and open possibilities for its application in computer aided diagnosis of other neuropsychiatric disorders, such as depression or schizophrenia.


Assuntos
Transtorno do Espectro Autista , Transtorno Autístico , Transtorno do Espectro Autista/diagnóstico por imagem , Transtorno Autístico/diagnóstico por imagem , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética , Redes Neurais de Computação
20.
Sensors (Basel) ; 21(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34451008

RESUMO

The purpose of this study was to investigate the feasibility of a time-of-flight (TOF) brain positron emission tomography (PET) providing high-quality images. It consisted of 30 detector blocks arranged in a ring with a diameter of 257 mm and an axial field of view of 52.2 mm. Each detector block was composed of two detector modules and two application-specific integrated circuit (ASIC) chips. The detector module was composed of an 8 × 8 array of 3 × 3 mm2 multi-pixel photon counters and an 8 × 8 array of 3.11 × 3.11 × 15 mm3 lutetium yttrium oxyorthosilicate scintillators. The 64-channel individual readout ASIC was used to acquire the position, energy, and time information of a detected gamma ray. A coincidence timing resolution of 187 ps full width at half maximum (FWHM) was achieved using a pair of channels of two detector modules. The energy resolution and spatial resolution were 6.6 ± 0.6% FWHM (without energy nonlinearity correction) and 2.5 mm FWHM, respectively. The results of this study demonstrate that the developed TOF brain PET could provide excellent performance, allowing for a reduction in radiation dose or scanning time for brain imaging due to improved sensitivity and signal-to-noise ratio.


Assuntos
Fótons , Tomografia por Emissão de Pósitrons , Encéfalo/diagnóstico por imagem , Eletrônica , Estudos de Viabilidade
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