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1.
Rev. argent. radiol ; 85(1): 11-20, ene. 2021. tab, graf
Article in Spanish | LILACS | ID: biblio-1155708

ABSTRACT

Resumen La presencia de lesiones quísticas de etiología oncológica en el encéfalo es cada vez más frecuente. El rol del especialista en imágenes es describir sus características, morfología y comportamiento con el contraste endovenoso, para llegar a realizar un diagnóstico presuntivo y enumerar sus diagnósticos diferenciales, y así orientar al médico tratante. Haremos una revisión de las lesiones quísticas de etiología oncológica de presentación frecuente en el encéfalo.


Abstract The presence of an oncologic cystic formation in the brain is frequent. The imaging specialist's role is to describe its features, morphology, and image enhancement characteristics with endovenous contrast, to make a presumptive diagnosis, and enumerated differential diagnoses and thus orientate the practitioner. We will analyze the most common expansive cystic formations.


Subject(s)
Brain Neoplasms/diagnostic imaging , Cysts/diagnostic imaging , Brain/pathology , Brain/diagnostic imaging , Magnetic Resonance Spectroscopy , Tomography, X-Ray Computed , Neurocytoma , Hemangioblastoma , Ependymoma
2.
Article in Chinese | WPRIM | ID: wpr-879282

ABSTRACT

Diffusion tensor imaging technology can provide information on the white matter of the brain, which can be used to explore changes in brain tissue structure, but it lacks the specific description of the microstructure information of brain tissue. The neurite orientation dispersion and density imaging make up for its shortcomings. But in order to accurately estimate the brain microstructure, a large number of diffusion gradients are needed, and the calculation is complex and time-consuming through maximum likelihood fitting. Therefore, this paper proposes a kind of microstructure parameters estimation method based on the proximal gradient network, which further avoids the classic fitting paradigm. The method can accurately estimate the parameters while reducing the number of diffusion gradients, and achieve the purpose of imaging quality better than the neurite orientation dispersion and density imaging model and accelerated microstructure imaging via convex optimization model.


Subject(s)
Brain/diagnostic imaging , Diffusion Magnetic Resonance Imaging , Diffusion Tensor Imaging , Neurites , White Matter
3.
Article in Chinese | WPRIM | ID: wpr-879248

ABSTRACT

The pathogenesis of Alzheimer's disease (AD), a common neurodegenerative disease, is still unknown. It is difficult to determine the atrophy areas, especially for patients with mild cognitive impairment (MCI) at different stages of AD, which results in a low diagnostic rate. Therefore, an early diagnosis model of AD based on 3-dimensional convolutional neural network (3DCNN) and genetic algorithm (GA) was proposed. Firstly, the 3DCNN was used to train a base classifier for each region of interest (ROI). And then, the optimal combination of the base classifiers was determined with the GA. Finally, the ensemble consisting of the chosen base classifiers was employed to make a diagnosis for a patient and the brain regions with significant classification capability were decided. The experimental results showed that the classification accuracy was 88.6% for AD


Subject(s)
Alzheimer Disease/diagnosis , Brain/diagnostic imaging , Cognitive Dysfunction/diagnosis , Early Diagnosis , Humans , Magnetic Resonance Imaging , Neural Networks, Computer , Neurodegenerative Diseases
4.
Chinese Medical Journal ; (24): 143-150, 2021.
Article in English | WPRIM | ID: wpr-878017

ABSTRACT

Age-related sporadic cerebral small vessel disease (CSVD) has gained increasing attention over the past decades because of its increasing prevalence associated with an aging population. The widespread application of and advances in brain magnetic resonance imaging in recent decades have significantly increased researchers' understanding in the in vivo evolution of CSVD, its impact upon the brain, its risk factors, and the mechanisms that explain the various clinical manifestation associated with sporadic CSVD. In this review, we aimed to provide an update on the pathophysiology, risk factors, biomarkers, and the determinants and spectrum of the clinical manifestation of sporadic CSVD.


Subject(s)
Aged , Aging , Brain/diagnostic imaging , Cerebral Small Vessel Diseases/epidemiology , Humans , Magnetic Resonance Imaging , Pandemics
5.
Frontiers of Medicine ; (4): 125-138, 2021.
Article in English | WPRIM | ID: wpr-880937

ABSTRACT

This study aimed to define the most consistent white matter microarchitecture pattern in Parkinson's disease (PD) reflected by fractional anisotropy (FA), addressing clinical profiles and methodology-related heterogeneity. Web-based publication databases were searched to conduct a meta-analysis of whole-brain diffusion tensor imaging studies comparing PD with healthy controls (HC) using the anisotropic effect size-signed differential mapping. A total of 808 patients with PD and 760 HC coming from 27 databases were finally included. Subgroup analyses were conducted considering heterogeneity with respect to medication status, disease stage, analysis methods, and the number of diffusion directions in acquisition. Compared with HC, patients with PD had decreased FA in the left middle cerebellar peduncle, corpus callosum (CC), left inferior fronto-occipital fasciculus, and right inferior longitudinal fasciculus. Most of the main results remained unchanged in subgroup meta-analyses of medicated patients, early stage patients, voxel-based analysis, and acquisition with 30 diffusion directions. The subgroup meta-analysis of medication-free patients showed FA decrease in the right olfactory cortex. The cerebellum and CC, associated with typical motor impairment, showed the most consistent FA decreases in PD. Medication status, analysis approaches, and the number of diffusion directions have an important impact on the findings, needing careful evaluation in future meta-analyses.


Subject(s)
Anisotropy , Brain/diagnostic imaging , Corpus Callosum , Diffusion Tensor Imaging , Humans , Parkinson Disease/diagnostic imaging , White Matter/diagnostic imaging
6.
Braz. j. med. biol. res ; 54(8): e11335, 2021. tab, graf
Article in English | LILACS | ID: biblio-1285674

ABSTRACT

Stereotactic biopsies for lesions in the brainstem and deep brain are rare. This study aimed to summarize our 6-year experience in the accurate diagnosis of lesions in the brain stem and deep brain and to discuss the technical note and strategies. From December 2011 to January 2018, 72 cases of intracranial lesions in the brainstem or deep in the lobes undergoing stereotactic biopsy were retrospectively reviewed. An individualized puncture path was designed based on the lesion's location and the image characteristics. The most common biopsy targets were deep in the lobes (43 cases, 59.7%), including frontal lobe (33 cases, 45.8%), temporal lobe (4 cases, 5.6%), parietal lobe (3 cases, 4.2%), and occipital lobe (3 cases, 4.2 %). There were 12 cases (16.7%) of the brainstem, including 8 cases (11.1%) of midbrain, and 4 cases (5.6%) of pons or brachium pontis. Other targets included internal capsule (2 cases, 2.8%), thalamus (3 cases, 4.2%), and basal ganglion (12 cases, 16.7%). As for complications, one patient developed acute intracerebral hemorrhage in the biopsy area at 2 h post-operation, and one patient had delayed intracerebral hemorrhage at 7 days post-operation. The remaining patients recovered well after surgery. There was no surgery-related death. The CT-MRI-guided stereotactic biopsy of lesions in the brainstem or deep in the brain has the advantages of high safety, accurate diagnosis, and low incidence of complications. It plays a crucial role in the diagnosis of atypical, microscopic, diffuse, multiple, and refractory lesions.


Subject(s)
Humans , Brain/diagnostic imaging , Stereotaxic Techniques , Biopsy , Brain Stem/diagnostic imaging , Retrospective Studies , Image-Guided Biopsy
10.
Rev. méd. Chile ; 148(7): 1034-1038, jul. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1139407

ABSTRACT

Paroxysmal sympathetic hyperactivity may appear after brain injury. Its clinical manifestations are sporadic and self-limited crisis of arterial hypertension, hyperthermia, tachycardia, hyperhidrosis, muscle tension, sialorrhea and mydriasis. These subside with the administration of morphine and beta-blockers. It may be caused by a dysautonomia leading to increased levels of catecholamines due to the lack of brain regulation. We report a 19 years-old man with a history of illicit drug and alcohol consumption, with a secondary axonal injury due to a cranioencephalic trauma. During hospitalization, he had recurrent, self-limited episodes of dysautonomia. An infectious cause was discarded. When morphine was administrated suspecting the presence of pain, the crisis subsided, which helped to establish the diagnosis of paroxysmal sympathetic hyperactivity.


Subject(s)
Humans , Male , Adult , Sympathetic Nervous System/pathology , Brain/diagnostic imaging , Hemorrhage/etiology , Sympathetic Nervous System/diagnostic imaging , Magnetic Resonance Imaging
11.
Arq. neuropsiquiatr ; 78(6): 370-379, June 2020. tab, graf
Article in English | LILACS | ID: biblio-1131710

ABSTRACT

ABSTRACT Background: Individuals with migraine usually complain about lower memory performance. Diagnostic methods such as neuroimaging may help in the understanding of possible morphologic and functional changes related to the memory of those individuals. Therefore, the aim of this review is to analyze the available literature on neuroimaging changes related to memory processing in migraine. Methods: We searched the following databases: Pubmed/Medline, Psycinfo, Science Direct, Cochrane and Web of Science. We used articles without restriction of year of publication. The combination of descriptors used for this systematic review of literature were Neuroimaging OR Imaging OR Brain AND Migraine OR Chronic Migraine AND Memory. Results: Of the 306 articles found, nine were selected and all used magnetic resonance imaging (MRI). The studies used structural and functional MRI techniques with a predominance of 3 Tesla equipment and T1-weighted images. According to the results obtained reported by these studies, migraine would alter the activity of memory-related structures, such as the hippocampus, insula and frontal, parietal and temporal cortices, thereby suggesting a possible mechanism by which migraine would influence memory, especially in relation to the memory of pain. Conclusions: Migraine is associated to global dysfunction of multisensory integration and memory processing. This condition changes the activity of structures in various regions related to memory of pain, prospective memory, as well as in short- and long-term verbal and visuospatial memories. However, it is necessary to perform studies with larger samples in association with cognitive tests, and without the interference of medications to verify possible alterations and to draw more concrete conclusions.


RESUMO Introdução: Indivíduos com enxaqueca geralmente se queixam de menor desempenho de memória. Métodos de diagnóstico como a neuroimagem podem auxiliar no entendimento de possíveis alterações morfológicas e funcionais relacionadas à memória desses indivíduos. Portanto, o objetivo desta revisão é analisar a literatura disponível sobre alterações de neuroimagem relacionadas a alterações de memória na enxaqueca. Métodos: Pesquisou-se nas seguintes bases de dados: PubMed/MEDLINE, Psycinfo, Science Direct, Cochrane e Web of Science. Foram utilizados artigos sem restrição de ano de publicação. A combinação dos descritores utilizados para esta revisão sistemática da literatura foram Neuroimaging OR Imaging OR Brain AND Migraine OR Chronic Migraine AND Memory. Resultados: Dos 306 artigos encontrados, nove foram selecionados e todos utilizaram ressonância magnética (RM). Os estudos utilizaram as técnicas de RM estrutural e funcional com predomínio de equipamentos de 3 Tesla e imagens ponderadas em T1. De acordo com os resultados obtidos nos estudos, a enxaqueca alteraria a atividade de estruturas relacionadas à memória, como o hipocampo, a ínsula e os córtices frontal, parietal e temporal, sugerindo um possível mecanismo pelo qual a enxaqueca influenciaria a memória, especialmente em relação à memória da dor. Conclusões: A enxaqueca está associada à disfunção global da integração multissensorial e processamento de memória. Essa condição altera a atividade de estruturas em várias regiões relacionadas à memória da dor, à memória prospectiva, bem como às memórias verbais e visuais-espaciais de curto e longo prazo. No entanto, é necessário realizar estudos com amostras maiores em associação com testes cognitivos, e sem a interferência de medicamentos para verificar possíveis alterações e tecer conclusões mais concretas.


Subject(s)
Humans , Neuroimaging , Migraine Disorders/diagnostic imaging , Brain/diagnostic imaging , Magnetic Resonance Imaging , Memory
13.
Journal of Biomedical Engineering ; (6): 1089-1094, 2020.
Article in Chinese | WPRIM | ID: wpr-879240

ABSTRACT

Hemispheric asymmetry is a fundamental organizing principle of the human brain. Answering the genetic effects of the asymmetry is a prerequisite for elucidating developmental mechanisms of brain asymmetries. Multi-modal magnetic resonance imaging (MRI) has provided an important tool for comprehensively interpreting human brain asymmetry and its genetic mechanism. By combining MRI data, individual differences in brain structural asymmetry have been investigated with quantitative genetic brain mapping using gene-heritability. Twins provide a useful natural model for studying the effects of genetics and environment on the brain. Studies based on MRI have found that the asymmetry of human brain structure has a genetic basis. From the perspective of quantitative genetic analysis, this article reviews recent findings on the genetic effects of asymmetry and genetic covariance between hemispheres from three aspects: the asymmetry of heritability, the heritability of asymmetry and the genetic correlation. At last, the article shows the limitations and future research directions in this field. The purpose of this systematic review is to quickly guide researchers to understand the origins and genetic mechanism of interhemispheric differences, and provide a genetic basis for further understanding and exploring individual differences in laterized cognitive behavior.


Subject(s)
Brain/diagnostic imaging , Brain Mapping , Humans , Magnetic Resonance Imaging , Twins/genetics
14.
Journal of Biomedical Engineering ; (6): 1037-1044, 2020.
Article in Chinese | WPRIM | ID: wpr-879234

ABSTRACT

To enhance the accuracy of computer-aided diagnosis of adolescent depression based on electroencephalogram signals, this study collected signals of 32 female adolescents (16 depressed and 16 healthy, age: 16.3 ± 1.3) with eyes colsed for 4 min in a resting state. First, based on the phase synchronization between the signals, the phase-locked value (PLV) method was used to calculate brain functional connectivity in the θ and α frequency bands, respectively. Then based on the graph theory method, the network parameters, such as strength of the weighted network, average characteristic path length, and average clustering coefficient, were calculated separately (


Subject(s)
Adolescent , Brain/diagnostic imaging , Diagnosis, Computer-Assisted , Electroencephalography , Female , Humans , Support Vector Machine
15.
Article in Chinese | WPRIM | ID: wpr-879216

ABSTRACT

In order to accurately implant the brain electrodes of carp robot for positioning and navigation, the three-dimensional model of brain structure and brain electrodes is to be proposed in the study. In this study, the tungsten electrodes were implanted into the cerebellum of a carp with the aid of brain stereotaxic instrument. The brain motor areas were found and their three-dimensional coordinate values were obtained by the aquatic electricity stimulation experiments and the underwater control experiments. The carp brain and the brain electrodes were imaged by 3.0 T magnetic resonance imaging instrument, and the three-dimensional reconstruction of carp brain and brain electrodes was carried out by the 3D-DOCTOR software and the Mimics software. The results showed that the brain motor areas and their coordinate values were accurate. The relative spatial position relationships between brain electrodes and brain tissue, brain tissue and skull surface could be observed by the three-dimensional reconstruction map of brain tissue and brain electrodes which reconstructed the three-dimensional structure of brain. The anatomical position of the three-dimensional reconstructed brain tissue in magnetic resonance image and the relationship between brain tissue and skull surface could be observed through the three-dimensional reconstruction comprehensive display map of brain tissue. The three-dimensional reconstruction model in this study can provide a navigation tool for brain electrodes implantation.


Subject(s)
Animals , Brain/diagnostic imaging , Carps , Electrodes , Electrodes, Implanted , Imaging, Three-Dimensional , Magnetic Resonance Imaging
16.
Article in Chinese | WPRIM | ID: wpr-879213

ABSTRACT

The construction of brain functional network based on resting-state functional magnetic resonance imaging (fMRI) is an effective method to reveal the mechanism of human brain operation, but the common brain functional network generally contains a lot of noise, which leads to wrong analysis results. In this paper, the least absolute shrinkage and selection operator (LASSO) model in compressed sensing is used to reconstruct the brain functional network. This model uses the sparsity of


Subject(s)
Algorithms , Brain/diagnostic imaging , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging
17.
Article in Chinese | WPRIM | ID: wpr-879201

ABSTRACT

Aiming at the difference between the brain networks of children with attention deficit hyperactivity disorder (ADHD) and normal children in the task-executing state, this paper conducted a comparative study using the network features of the visual function area. Functional magnetic resonance imaging (fMRI) data of 23 children with ADHD [age: (8.27 ± 2.77) years] and 23 normal children [age: (8.70 ± 2.58) years] were obtained by the visual capture paradigm when the subjects were performing the guessing task. First, fMRI data were used to build a visual area brain function network. Then, the visual area brain function network characteristic indicators including degree distribution, average shortest path, network density, aggregation coefficient, intermediary, etc. were obtained and compared with the traditional whole brain network. Finally, support vector machines (SVM) and other classifiers in the machine learning algorithm were used to classify the feature indicators to distinguish ADHD children from normal children. In this study, visual brain function network features were used for classification, with a classification accuracy of up to 96%. Compared with the traditional method of constructing a whole brain network, the accuracy was improved by about 10%. The test results show that the use of visual area brain function network analysis can better distinguish ADHD children from normal children. This method has certain help to distinguish the brain network between ADHD children and normal children, and is helpful for the auxiliary diagnosis of ADHD children.


Subject(s)
Attention Deficit Disorder with Hyperactivity/diagnostic imaging , Brain/diagnostic imaging , Brain Mapping , Child , Child, Preschool , Cognition , Humans , Magnetic Resonance Imaging
18.
Chinese Medical Journal ; (24): 344-352, 2020.
Article in English | WPRIM | ID: wpr-877885

ABSTRACT

BACKGROUND@#Resting-state functional magnetic resonance imaging (rs-fMRI) is a promising method for the study of brain function. Typically, rs-fMRI is performed on anesthetized animals. Although different functional connectivity (FC) in various anesthetics on whole brain have been studied, few studies have focused on different FC in the aged brain. Here, we measured FC under three commonly used anesthesia methods and analyzed data to determine if the FC in whole brain analysis were similar among groups.@*METHODS@#Twenty-four male aged Wistar rats were randomly divided into three groups (n = 8 in each group). Anesthesia was performed under either isoflurane (ISO), combined ISO + dexmedetomidine (DEX) or α-chloralose (AC) according to the groups. Data of rs-fMRI was analyzed by FC in a voxel-wise way. Differences in the FC maps between the groups were analyzed by one-way analysis of variance and post hoc two-sample t tests.@*RESULTS@#Compared with ISO + DEX anesthesia, ISO anesthesia caused increased FC in posterior brain and decreased FC in the middle brain of the aged rat. AC anesthesia caused global suppression as no increase in FC was observed.@*CONCLUSION@#ISO could be used as a substitute for ISO + DEX in rat default mode network studies if the left temporal association cortex is not considered important.


Subject(s)
Anesthesia , Animals , Brain/diagnostic imaging , Brain Mapping , Isoflurane , Magnetic Resonance Imaging , Male , Rats , Rats, Wistar
19.
Rev. Soc. Bras. Med. Trop ; 53: e20190557, 2020. tab, graf
Article in English | LILACS, ColecionaSUS, SES-SP | ID: biblio-1143865

ABSTRACT

Abstract INTRODUCTION: Congenital infection by the Zika virus (ZIKV) is responsible for severe abnormalities in the development of the central nervous system. The aim of this study was to evaluate and compare the ability of computed tomography (CT) and magnetic resonance (MR) to detect patterns of involvement of the central nervous system in congenital ZIKV syndrome. METHODS: We retrospectively analyzed CT and MR images from 34 patients with congenital ZIKV syndrome and evaluated the differences between the two methods in detecting alterations. RESULTS: The predominant radiographic finding was a simplified gyral pattern, present in 97% of cases. The second most common finding was the presence of calcifications (94.1%), followed by ventriculomegaly (85.3%), dysgenesis of the corpus callosum (85.3%), craniofacial disproportion and redundant scalp (79.4%), complete opercular opening (79.4%), occipital prominence (44.1%), cerebellar hypoplasia (14.7%), and pontine hypoplasia (11.8%). The gyral pattern was extensively simplified in most cases, and calcifications were located predominantly at the cortical-subcortical junction. CT was able to better identify calcifications (94.1% × 88.2%), while MRI presented better spatial resolution for the characterization of gyral pattern (97% × 94.1%) and corpus callosum dysgenesis (85.3% × 79.4%). CONCLUSIONS: Although congenital ZIKV syndrome does not present pathognomonic neuroimaging findings, some aspects, such as calcifications at the cortical-subcortical junction, especially when associated with compatible clinical and laboratory findings, are suggestive of intrauterine ZIKV infection.


Subject(s)
Humans , Female , Pregnancy , Infant, Newborn , Child , Pregnancy Complications, Infectious , Zika Virus , Zika Virus Infection/diagnostic imaging , Microcephaly/diagnostic imaging , Brain/diagnostic imaging , Magnetic Resonance Imaging , Tomography, X-Ray Computed , Retrospective Studies , Neuroimaging
20.
Frontiers of Medicine ; (4): 792-801, 2020.
Article in English | WPRIM | ID: wpr-880935

ABSTRACT

Asthma is a serious health problem that involves not only the respiratory system but also the central nervous system. Previous studies identified either regional or network alterations in patients with asthma, but inconsistent results were obtained. A key question remains unclear: are the regional and neural network deficits related or are they two independent characteristics in asthma? Answering this question is the aim of this study. By collecting resting-state functional magnetic resonance imaging from 39 patients with asthma and 40 matched health controls, brain functional measures including regional activity (amplitude of low-frequency fluctuations) and neural network function (degree centrality (DC) and functional connectivity) were calculated to systematically characterize the functional alterations. Patients exhibited regional abnormities in the left angular gyrus, right precuneus, and inferior temporal gyrus within the default mode network. Network abnormalities involved both the sensorimotor network and visual network with key regions including the superior frontal gyrus and occipital lobes. Altered DC in the lingual gyrus was correlated with the degree of airway obstruction. This study elucidated different patterns of regional and network changes, thereby suggesting that the two parameters reflect different brain characteristics of asthma. These findings provide evidence for further understanding the potential cerebral alterations in the pathophysiology of asthma.


Subject(s)
Asthma/diagnostic imaging , Brain/diagnostic imaging , Brain Mapping , Humans , Magnetic Resonance Imaging
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