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1.
Journal of Southern Medical University ; (12): 1224-1232, 2023.
Artigo em Chinês | WPRIM | ID: wpr-987039

RESUMO

OBJECTIVE@#To propose a diffusion tensor field estimation network based on 3D U-Net and diffusion tensor imaging (DTI) model constraint (3D DTI-Unet) to accurately estimate DTI quantification parameters from a small number of diffusion-weighted (DW) images with a low signal-to-noise ratio.@*METHODS@#The input of 3D DTI-Unet was noisy diffusion magnetic resonance imaging (dMRI) data containing one non-DW image and 6 DW images with different diffusion coding directions. The noise-reduced non-DW image and accurate diffusion tensor field were predicted through 3D U-Net. The dMRI data were reconstructed using the DTI model and compared with the true value of dMRI data to optimize the network and ensure the consistency of the dMRI data with the physical model of the diffusion tensor field. We compared 3D DTI-Unet with two DW image denoising algorithms (MP-PCA and GL-HOSVD) to verify the effect of the proposed method.@*RESULTS@#The proposed method was better than MP-PCA and GL-HOSVD in terms of quantitative results and visual evaluation of DW images, diffusion tensor field and DTI quantification parameters.@*CONCLUSION@#The proposed method can obtain accurate DTI quantification parameters from one non-DW image and 6 DW images to reduce image acquisition time and improve the reliability of quantitative diagnosis.


Assuntos
Imagem de Tensor de Difusão , Reprodutibilidade dos Testes , Imagem de Difusão por Ressonância Magnética , Algoritmos , Razão Sinal-Ruído
2.
Chinese Journal of Traumatology ; (6): 8-13, 2023.
Artigo em Inglês | WPRIM | ID: wpr-970963

RESUMO

Pediatric and adult spinal cord injuries (SCI) are distinct entities. Children and adolescents with SCI must suffer from lifelong disabilities, which is a heavy burden on patients, their families and the society. There are differences in Chinese and foreign literature reports on the incidence, injury mechanism and prognosis of SCI in children and adolescents. In addition to traumatic injuries such as car accidents and falls, the proportion of sports injuries is increasing. The most common sports injury is the backbend during dance practice. Compared with adults, children and adolescents are considered to have a greater potential for neurological improvement. The pathogenesis and treatment of pediatric SCI remains unclear. The mainstream view is that the mechanism of nerve damage in pediatric SCI include flexion, hyperextension, longitudinal distraction and ischemia. We also discuss the advantages and disadvantages of drugs such as methylprednisolone in the treatment of pediatric SCI and the indications and timing of surgery. In addition, the complications of pediatric SCI are also worthy of attention. New imaging techniques such as diffusion tensor imaging and diffusion tensor tractography may be used for diagnosis and assessment of prognosis. This article reviews the epidemiology, pathogenesis, imaging, clinical characteristics, treatment and complications of SCI in children and adolescents. Although current treatment cannot completely restore neurological function, patient quality of life can be enhanced. Continued developments and advances in the research of SCI may eventually provide a cure for children and adolescents with this kind of injury.


Assuntos
Adulto , Criança , Humanos , Adolescente , Imagem de Tensor de Difusão/métodos , Qualidade de Vida , Traumatismos da Medula Espinal/terapia , Prognóstico , Traumatismos em Atletas , Medula Espinal/patologia
3.
Chinese Journal of Industrial Hygiene and Occupational Diseases ; (12): 57-62, 2023.
Artigo em Chinês | WPRIM | ID: wpr-970713

RESUMO

Acute carbon monoxide poisoning and its delayed encephalopathy have obvious damage to the central nervous system. There are different neuroimaging changes in different stages of the disease, and they are relatively specific. This article reviews the clinical research progress on the imaging changes of carbon monoxide poisoning and delayed encephalopathy, including computed tomography (CT) , conventional magnetic resonance imaging (MRI) , diffusion weighted imaging (DWI) , diffusion tensor imaging (DTI) , diffusion kurtosis imaging (DKI) , magnetic resonance spectroscopy (MRS) and other imaging changes reflecting the function and metabolic state of the brain tissue.


Assuntos
Humanos , Encefalopatias/etiologia , Intoxicação por Monóxido de Carbono/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , Espectroscopia de Ressonância Magnética
4.
Chinese Journal of Surgery ; (12): 61-65, 2023.
Artigo em Chinês | WPRIM | ID: wpr-970174

RESUMO

Objective: To examine the application value of 3D Slicer software assisted domestic frameless stereotactic robot in biopsy of intracranial lesions. Methods: A retrospective analysis was performed on 80 patients who admitted consecutively and underwent intracerebral lesions biopsy with the domestic frameless stereotactic robot at Department of Neurosurgery, Aerospace Central Hospital from January 2019 to December 2021. There were 36 males and 44 females, with a mean age of (38.5±18.0) years (range: 6 to 71 years). Before surgery only enhanced T1-weighted three-dimensional magnetization prepared gradient echo sequences and diffusion tensor imaging scans were performed. Self-reconstruction of intracranial lesions, cerebral cortex and blood vessels was carried out using 3D Slicer software system after the DICOM format imaging data of 80 patients were collected. These imaging data were merged to the workstation of the domestic frameless stereotactic robot for preoperative surgical planning and the surgical puncture path was designed to avoid blood vessels in the brain functional area, cerebral cortex and sulcus. Results: All frameless stereotactic biopsy were successfully performed. Postoperative pathological diagnosis included 50 cases of diffuse astrocytic and oligodendroglioma, 15 cases of lymphoma, 5 cases of metastatic tumors, 5 cases of inflammatory demyelinating disease, 2 cases of inflammatory granuloma, 1 case of hemangioma, 1 case of acute lymphoblastic leukemia intracranial invasion and 1 case of seminoma. The positive diagnosis rate was 100% (80/80). Postoperative imaging confirmed that the puncture path and target were accurately implemented according to the preoperative planning, and the target error was (1.32±0.44) mm (range: 0.55 to 1.99 mm). One case of puncture-related bleeding occurred at the target after surgery and improved after treatment. Conclusion: The three-dimensional multimodal images reconstructed by the 3D Slicer software before operation could help the surgeons make the preoperative planning and reduce the risk of stereotactic brain biopsy.


Assuntos
Masculino , Feminino , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Neoplasias Encefálicas/patologia , Imagem de Tensor de Difusão , Estudos Retrospectivos , Robótica , Biópsia , Software , Técnicas Estereotáxicas
5.
Chinese Acupuncture & Moxibustion ; (12): 163-169, 2023.
Artigo em Chinês | WPRIM | ID: wpr-969966

RESUMO

OBJECTIVE@#To observe the clinical efficacy of scalp acupuncture for spastic cerebral palsy (CP), and to explore its possible mechanism based on brain white matter fiber bundles, nerve growth related proteins and inflammatory cytokines.@*METHODS@#A total of 90 children with spastic CP were randomly divided into a scalp acupuncture group and a sham scalp acupuncture group, 45 cases in each group. The children in the two groups were treated with conventional comprehensive rehabilitation treatment. The children in the scalp acupuncture group were treated with scalp acupuncture at the parietal temporal anterior oblique line, parietal temporal posterior oblique line on the affected side, and parietal midline. The children in the sham scalp acupuncture group were treated with scalp acupuncture at 1 cun next to the above point lines. The needles were kept for 30 min, once a day, 5 days a week, for 12 weeks. Before and after treatment, the diffusion tensor imaging (DTI) indexes of magnetic resonance (FA values of corticospinal tract [CST], anterior limb of internal capsule [ICAL], posterior limb of internal capsule [ICPL], genu of internal capsule [ICGL], genu of corpus callosum [GCC], body of corpus callosum [BCC] and splenium of corpus callosum [SCC]), serum levels of nerve growth related proteins (neuron-specific enolase [NSE], glial fibrillary acidic protein [GFAP], myelin basic protein [MBP], ubiquitin carboxy terminal hydrolase-L1 [UCH-L1]) and inflammatory cytokines (interleukin 33 [IL-33], tumor necrosis factor α [TNF-α]), cerebral hemodynamic indexes (mean blood flow velocity [Vm], systolic peak flow velocity [Vs] and resistance index [RI], pulsatility index [PI] of cerebral artery), surface electromyography (SEMG) signal indexes (root mean square [RMS] values of rectus femoris, hamstring muscles, gastrocnemius muscles, tibialis anterior muscles), gross motor function measure-88 (GMFM-88) score, modified Ashworth scale (MAS) score, ability of daily living (ADL) score were observed in the two groups. The clinical effect of the two groups was compared.@*RESULTS@#After treatment, the FA value of each fiber bundle, Vm, Vs, GMFM-88 scores and ADL scores in the two groups were higher than those before treatment (P<0.05), and the above indexes in the scalp acupuncture group were higher than those in the sham scalp acupuncture group (P<0.05). After treatment, the serum levels of NSE, GFAP, MBP, UCH-L1, IL-33, TNF-α as well as RI, PI, MAS scores and RMS values of each muscle were lower than those before treatment (P<0.05), and the above indexes in the scalp acupuncture group were lower than those in the sham scalp acupuncture group (P<0.05). The total effective rate was 95.6% (43/45) in the scalp acupuncture group, which was higher than 82.2% (37/45) in the sham scalp acupuncture group (P<0.05).@*CONCLUSION@#Scalp acupuncture could effectively treat spastic CP, improve the cerebral hemodynamics and gross motor function, reduce muscle tension and spasticity, and improve the ability of daily life. The mechanism may be related to repairing the white matter fiber bundles and regulating the levels of nerve growth related proteins and inflammatory cytokines.


Assuntos
Criança , Humanos , Paralisia Cerebral/terapia , Interleucina-33 , Imagem de Tensor de Difusão/métodos , Couro Cabeludo , Espasticidade Muscular , Fator de Necrose Tumoral alfa , Terapia por Acupuntura , Citocinas
6.
Journal of Biomedical Engineering ; (6): 401-408, 2023.
Artigo em Chinês | WPRIM | ID: wpr-981556

RESUMO

In transcranial magnetic stimulation (TMS), the conductivity of brain tissue is obtained by using diffusion tensor imaging (DTI) data processing. However, the specific impact of different processing methods on the induced electric field in the tissue has not been thoroughly studied. In this paper, we first used magnetic resonance image (MRI) data to create a three-dimensional head model, and then estimated the conductivity of gray matter (GM) and white matter (WM) using four conductivity models, namely scalar (SC), direct mapping (DM), volume normalization (VN) and average conductivity (MC), respectively. Isotropic empirical conductivity values were used for the conductivity of other tissues such as the scalp, skull, and cerebrospinal fluid (CSF), and then the TMS simulations were performed when the coil was parallel and perpendicular to the gyrus of the target. When the coil was perpendicular to the gyrus where the target was located, it was easy to get the maximum electric field in the head model. The maximum electric field in the DM model was 45.66% higher than that in the SC model. The results showed that the conductivity component along the electric field direction of which conductivity model was smaller in TMS, the induced electric field in the corresponding domain corresponding to the conductivity model was larger. This study has guiding significance for TMS precise stimulation.


Assuntos
Estimulação Magnética Transcraniana , Imagem de Tensor de Difusão , Condutividade Elétrica , Eletricidade , Couro Cabeludo
7.
j.tunis.ORL chir. cerv.-fac ; 49: 5-12, 2023. figures, tables
Artigo em Francês | AIM | ID: biblio-1428019

RESUMO

Décrire les caractéristiques radiologiques de la brèche ostéo-méningée (BOM) de l'étage antérieur de la base du crâne. Méthodes: Etude rétrospective, descriptive, monocentrique, colligeant les patients hospitalisés pour prise en charge d'une brèche ostéoméningée (BOM) et explorés par le couple TDM/IRM, du 1er janvier 2012 au 31 Décembre 2021. Résultats: Ont été retenu 23 patients avec un âge moyen de 48 ans et un sex ratio de 0,3. Des antécédents de chirurgie nasosinusienne ou de neurochirurgie ont été notés chez deux patients (9 %). Treize patients (57 %) étaient victimes de traumatisme crânien. Une rhinoliquorrhée était retrouvée dans 21 cas (persistante dans trois cas (12%) et intermittente dans 18 cas (76%)). La découverte de la BOM a été faite suite à une méningite dans quatre cas. Le dosage de la bêta trace a confirmé la présence de LCR chez deux patients. La TDM a confirmé le diagnostic chez 12 patients dont deux patients qui ne présentaient pas de rhinoliquorrhée à l'examen clinique. Elle a aussi permis d'établir le bilan topographique dans ces cas. Elle a suspecté une BOM dans 9 cas et était négative dans deux cas. L'IRM a confirmé le diagnostic dans tous les cas et a permis de: localiser le siège de la fuite de LCR dans les brèches multiples, confirmer le diagnostic deméningoencéphalocèle (trois cas) et objectiver des signes indirects d'hypertension intra-crânienne (HTIC) (quatre cas). Conclusion: L'imagerie en coupes permet de localiser la BOM mais nécessite souvent, une approche par étapes et son interprétation exige une connaissance approfondie de l'anatomie normale et des variantes de la base du crâne. Mots-clés: Liquorrhée, Brèche Ostéoméningée, Chirurgie, TDM, IRM


Assuntos
Humanos , Encefalocele , Imagem de Tensor de Difusão , Cirurgia Geral , Vazamento de Líquido Cefalorraquidiano , Rinorreia , Neurocirurgia
8.
Int. j. morphol ; 40(6): 1594-1601, dic. 2022. ilus, tab, graf
Artigo em Inglês | LILACS | ID: biblio-1421826

RESUMO

SUMMARY: Anatomy education has gathered together a great many of many new modalities and was modified from classical lecture-based and laboratory practice system to the blended modules. In the scope of the present study, we develop a new, practical, cost- effective and efficient three dimensional (3D) educational model, which aimed to be helpful for the detection and better understanding of basic neuroanatomy education. Tractographic imaging, fiber dissection, microscopic anatomy and plastination techniques were applied to the white matter regions of the two brains. After the photographs that were taken were converted to 3D images, the specimens were plastinated. By way of establishing an educational model as a whole, we applied it to 202 second-year medical students. The students were separated into two groups when they attended to the theoretical lecture. Group 1 took the classical laboratory education; on the other hand, Group 2 received the newly designed educational model. Pre and post-tests were introduced to each group before and after laboratory sessions, respectively. The success scores were put to comparison. The average achievement scores of each group showed increase significantly (p<0.05) after the laboratory sessions, besides the increase in the post-test results of Group 2 was more statistically significant (p<0.05). Consequently, this new educational model enriched by newly designed unified methods could be regarded as useful for grasping and improving the basic neuroanatomy knowledge.


La educación en anatomía ha reunido una gran cantidad de nuevas modalidades, modificándose el sistema clásico de la práctica del laboratorio y de las clases basadas en conferencias, hacia los módulos combinados. En el ámbito del presente estudio, desarrollamos un modelo educativo tridimensional (3D) nuevo, práctico, rentable y eficiente, que pretendía ser útil para la detección y una mejor comprensión de la educación básica en neuroanatomía. Se tomaron imágenes tractográficas, disección de fibras, anatomía microscópica y técnicas de plastinación en los cerebros. Después de convertir las fotografías que se tomaron en imágenes 3D, se plastinaron los especímenes. A modo de establecer un modelo educativo en su conjunto, lo aplicamos a 202 estudiantes de segundo año de medicina. Los estudiantes fueron separados en dos grupos cuando asistieron a la clase teórica. El Grupo 1 tomó la educación clásica de laboratorio; por su parte, el Grupo 2 recibió el nuevo modelo educativo diseñado para el estudio. Se introdujeron pruebas previas y posteriores a cada grupo, antes y después de las sesiones de laboratorio. Se compararon las puntuaciones. Los puntajes promedio de rendimiento de cada grupo mostraron un aumento significativo (p<0,05) después de las sesiones de laboratorio. Además, se obtuvo un aumento en los resultados positivos, posteriores a la prueba del Grupo 2, siendo estadísticamente significativo (p<0,05). En consecuencia, este modelo educativo, enriquecido por métodos unificados de nuevo diseño, podría considerarse útil para captar y mejorar los conocimientos básicos de neuroanatomía.


Assuntos
Humanos , Modelos Educacionais , Educação Médica/métodos , Neuroanatomia/educação , Dissecação , Cérebro/anatomia & histologia , Imagem de Tensor de Difusão , Substância Branca/anatomia & histologia , Plastinação , Microscopia , Fibras Nervosas
9.
Arq. neuropsiquiatr ; 79(6): 483-488, June 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1285363

RESUMO

Abstract Background: Migraine is a prevalent neurological disease that leads to severe headaches. Moreover, it is the commonest among the primary headaches that cause medication overuse headache (MOH). The orbitofrontal cortex (OFC) is one of the structures most associated with medication overuse. Objective: To determine microstructural changes in the OFC among migraine patients who developed MOH, through the diffusion tensor imaging (DTI) technique. Methods: Fifty-eight patients who had been diagnosed with migraine based on the Classification of Headache Disorders (ICHD-III-B) were included in the study. Patients were sub-classified into two groups, with and without MOH, based on the MOH criteria of ICHD-III-B. DTI was applied to each patient. The OFC fractional anisotropy (FA), and apparent diffusion coefficient (ADC) values of the two groups were compared. Results: The mean age of all the patients was 35.98±7.92 years (range: 18-65), and 84.5% (n=49) of them were female. The two groups, with MOH (n=25) and without (n=33), were alike in terms of age, gender, family history, migraine with or without aura and duration of illness. It was found that there was a significant difference in FA values of the left OFC between the two groups (0.32±0.01 versus 0.29±0.01; p=0.04). Conclusions: An association was found between MOH and changes to OFC microstructure. Determination of neuropathology and factors associated with medication overuse among migraine patients is crucial in terms of identifying the at-risk patient population and improving proper treatment strategies specific to these patients.


RESUMO Introdução: A migrânea é uma doença neurológica prevalente que causa fortes dores de cabeça. Além disso, é a mais comum entre as cefaleias primárias que causam cefaleia por uso excessivo de medicamentos (CUEM). O córtex orbitofrontal (OF) é uma das estruturas mais associadas ao uso excessivo de medicamentos. Objetivo: Determinar alterações microestruturais no córtex OF em pacientes com migrânea que desenvolveram CUEM, por meio da técnica de imagem por tensor de difusão (ITD). Métodos: Cinquenta e oito pacientes com diagnóstico de migrânea, com base na Classificação das Cefaleias (ICHD-III-B), foram incluídos no estudo. Os pacientes foram subclassificados em dois grupos, com e sem CUEM, com base nos critérios de CUEM da ICHD-III-B. A ITD foi aplicada a cada paciente. Os valores de anisotropia fracionada OFC (AF) e coeficiente de difusão aparente (CDA) dos dois grupos foram comparados. Resultados: A média de idade de todos os pacientes foi de 35,98±7,92 anos (variação: 18‒65), sendo 84,5% (n=49) do sexo feminino. Os dois grupos, com CUEM (n=25) e sem (n=33), são semelhantes em termos de idade, sexo, história familiar, migrânea com ou sem aura e duração da doença. Verificou-se que houve diferença significativa nos valores de AF do córtex OF esquerdo entre os dois grupos (0,32±0,01 versus 0,29±0,01; p=0,04). Conclusões: Foi encontrada associação entre o CUEM e as alterações na microestrutura do córtex OF. A determinação da neuropatologia e dos fatores associados ao uso excessivo de medicamentos entre pacientes com migrânea é crucial para identificar a população de pacientes em risco e melhorar as estratégias de tratamento adequadas específicas para esses pacientes.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Idoso , Adulto Jovem , Transtornos da Cefaleia Secundários/diagnóstico por imagem , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/diagnóstico por imagem , Córtex Pré-Frontal , Imagem de Tensor de Difusão , Uso Excessivo de Medicamentos Prescritos , Pessoa de Meia-Idade
10.
Frontiers of Medicine ; (4): 125-138, 2021.
Artigo em Inglês | WPRIM | ID: wpr-880937

RESUMO

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.


Assuntos
Humanos , Anisotropia , Encéfalo/diagnóstico por imagem , Corpo Caloso , Imagem de Tensor de Difusão , Doença de Parkinson/diagnóstico por imagem , Substância Branca/diagnóstico por imagem
11.
Journal of Central South University(Medical Sciences) ; (12): 414-420, 2021.
Artigo em Inglês | WPRIM | ID: wpr-880675

RESUMO

Magnetic resonance imaging (MRI) is a very important imaging method for diagnosis and treatment of prostate cancer (PCa) in clinical practice. As functional MRI is growing and maturing, its quantitative parameters are expected to enhance the clinical value of MRI furtherly. Intravoxel incoherent motion diffusion imaging, diffusion tensor imaging, and diffusion kurtosis imaging, which were derived from diffusion weighted imaging, have provided richer and more accurate parameters. The newly-developed magnetic resonance elastography can complement the mechanical characteristics of PCa.


Assuntos
Humanos , Masculino , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Imageamento por Ressonância Magnética , Movimento (Física) , Neoplasias da Próstata/diagnóstico por imagem
12.
Acta Physiologica Sinica ; (6): 407-422, 2021.
Artigo em Chinês | WPRIM | ID: wpr-887677

RESUMO

As the two essential components, the white matter and gray matter compose the central nervous system of the brain. Widely known that axons of neurons mainly form the white matter, and these formed nerve fibers are responsible for transmitting information among various brain regions to achieve the coordinated operation of the entire brain. Early research on the white matter could only be done by dissecting living animals or human cadavers, until Basser et al. proposed diffusion tensor imaging (DTI) technology in 1994, which could detect the diffusion characteristics of water in the brain in vivo noninvasively. Accordingly, this technology could be applied to investigate the diffusion movement of water in white matter to obtain the information of direction and micro-anatomy of white matter fiber bundles. With the advancement on the display and analysis of the anatomical structure of white matter fiber bundles, the exploration of microscopic pathological changes, and the assistance of clinical diagnosis and neurophysiological research, DTI technology has become one of the most popular topics in brain science research. Chronic pain refers to pain lasting more than three months, which not only seriously affects the patient's physical and social functions, but also dramatically reduces the quality of life. It was reported that long-term pain stimulation might cause pathological remodeling of the central nervous system, and abnormalities in white matter were found in imaging examinations of patients with chronic pain. This review introduces the quantitative analysis methods of white matter fiber bundle microstructure based on DTI and its application in chronic pain, and further discusses the application value of DTI technology on clinical research of chronic pain.


Assuntos
Animais , Humanos , Encéfalo , Dor Crônica/diagnóstico por imagem , Imagem de Tensor de Difusão , Qualidade de Vida , Substância Branca/diagnóstico por imagem
13.
Journal of Biomedical Engineering ; (6): 333-341, 2021.
Artigo em Chinês | WPRIM | ID: wpr-879282

RESUMO

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.


Assuntos
Encéfalo/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Neuritos , Substância Branca
14.
Korean Journal of Radiology ; : 332-340, 2020.
Artigo em Inglês | WPRIM | ID: wpr-810980

RESUMO

OBJECTIVE: We aimed to investigate the ability of readout-segmented echo-planar imaging (rs-EPI)-based diffusion tensor imaging (DTI) in assessing the microstructural change of extraocular muscles (EOMs) and optic nerves in patients with thyroid-associated orbitopathy (TAO) as well as in evaluating disease activity.MATERIALS AND METHODS: We enrolled 35 TAO patients and 22 healthy controls (HCs) who underwent pre-treatment rs-EPI-based DTI. Mean, axial, and radial diffusivity (MD, AD, and RD) and fractional anisotropy (FA) of the medial and lateral EOMs and optic nerve for each orbit were calculated and compared between TAO and HC groups and between active and inactive TAO groups. Factors such as age, sex, disease duration, mediation, and smoking history between groups were also compared. Logistic regression analysis was used to evaluate the predictive value of significant variables for disease activity.RESULTS: Disease duration was significantly shorter in active TAOs than in inactive ones (p < 0.001). TAO patients showed significantly lower FA and higher MD, AD, and RD than HCs for both medial and lateral EOMs (p < 0.001), but not the AD value of lateral EOMs (p = 0.619). Active patients had significantly higher FA, MD, and AD than inactive patients for medial EOMs (p < 0.005), whereas only FA differed significantly in the lateral EOMs (p = 0.018). The MD, AD, and RD of optic nerves were significantly lower in TAO patients than HCs (p < 0.05), except for FA (p = 0.129). Multivariate analysis showed that the MD of medial EOMs and disease duration were significant predictors for disease activity. The combination of these two parameters showed optimal diagnostic efficiency for disease activity (area under the curve, 0.855; sensitivity, 68.4%; specificity, 96.9%).CONCLUSION: rs-EPI-based DTI is promising in assessing microstructural changes of EOMs and optic nerves and can help to indicate the disease activity of TAO, especially through the MD of medial EOMs.


Assuntos
Humanos , Anisotropia , Imagem de Tensor de Difusão , Difusão , Imagem Ecoplanar , Modelos Logísticos , Análise Multivariada , Músculos , Negociação , Nervo Óptico , Órbita , Sensibilidade e Especificidade , Fumaça , Fumar , Troleandomicina
15.
Acta Academiae Medicinae Sinicae ; (6): 154-163, 2020.
Artigo em Chinês | WPRIM | ID: wpr-826387

RESUMO

To compare the differences in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) between brucella spondylitis (BS) groups at different stages before treatment and the normal control group and to evaluate the change trend of ADC value and FA value at different time points before and after treatment. Totally 53 patients suspected of BS by conventional magnetic resonance imaging (MRI) and later confirmed as BS patients by serological tests were enrolled in this study. These patients underwent conventional MRI and diffusion tensor imaging scans,and the ADC value and FA value were measured. Independent sample test was used to compare the ADC value and FA value between the BS group and the control group,the ADC value and FA value between the BS group at each stage. Repeated measurement ANOV was used to compare the ADC values and FA values at different time points before and after treatment. FA imaging showed that the color code of BS was different from that of the normal control group,and the color code of FA imaging showed increased singal. The ADC values of BS in the acute,subacute,and chronic stages [(1.45±0.02)×10 mm /s,(1.35±0.03)×10 mm /s,(1.26±0.05)×10 mm /s,respectively] were significantly higher than those in the control group [(1.06±0.09) ×10 mm /s](=2.538,=0.009;=1.998,=0.032;=1.575,=0.004),and the FA value (0.55±0.02,0.65±0.03,0.71±0.04,respectively) were significantly lower than those of the control group (0.78±0.02) (=2.440,=0.012; =1.847,=0.041;=2.102,=0.003). Repeated measurement analysis showed that there were statistically significant differences in ADC values and FA values at different time points before and after treatment in the acute,subacute,and chronic stages (ADC:=12.100,<0.001;=8.439,=0.005;=9.704,=0.004,respectively;FA:=7.080,=0.002;=6.607;=0.003;=8.868,=0.001,respectively). The ADC values at different time points after treatment were significantly lower than those before treatment or at a previous time point after treatment (=332.14,<0.001),and the FA values were significantly higher than those before treatment or at a previous time point after treatment (=134.26,<0.001). FA color code can intuitively display differences in BS and normal vertebral bodies and show change of color code before and after treatment. Also,the ADC values and FA values can quantitatively reveal differences between BS and normal vertebral body in different time points and quantify BS vertebral lesion changes before and after treatment. In particular,in BS patients who are recovering from treatment,it can quantify microscopic edema. Therefore,diffusion tensor imaging may be useful objective indicator in evaluating the effectiveness of a specific treatment for BS.


Assuntos
Humanos , Anisotropia , Brucella , Brucelose , Diagnóstico por Imagem , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Espondilite , Diagnóstico por Imagem , Microbiologia
16.
Chinese Journal of Contemporary Pediatrics ; (12): 711-715, 2020.
Artigo em Chinês | WPRIM | ID: wpr-828679

RESUMO

OBJECTIVE@#To study the value of fractional anisotropy (FA) of regions of interest (ROI) on magnetic resonance diffusion tensor imaging (DTI) in bilirubin-induced neurological dysfunction in neonates.@*METHODS@#A total of 91 neonates with hyperbilirubinemia who were hospitalized from January 2017 to January 2018 were enrolled. According to the peak level of total serum bilirubin, they were divided into three groups: mild/moderate increase (n=45), severe increase (n=35), and extremely severe increase (n=11). According to the presence or absence of abnormal neurological manifestations, they were divided into two groups: neurological dysfunction (n=20) and non-neurological dysfunction (n=71). Ten healthy full-term infants were enrolled as the control group. Head DTI was performed for all neonates to measure the FA values of the bilateral globus pallidus, the anterior limb of the internal capsule, the posterior limb of the internal capsule, and the cerebellar dentate nucleus.@*RESULTS@#The extremely severe increase group had significantly lower FA values of the globus pallidus than the control, mild/moderate increase, and severe increase groups (P<0.05). The severe increase group had significantly lower FA values of the globus pallidus than the control group (P<0.05). The extremely severe increase group had significantly lower FA values of the posterior limb of the internal capsule than the control, mild/moderate increase, and severe increase groups (P<0.05). The neurological dysfunction group had significantly lower FA values of the globus pallidus and the posterior limb of the internal capsule than the non-neurological dysfunction group (P<0.05).@*CONCLUSIONS@#Serum bilirubin level combined with the changes in the DTI FA values of the globus pallidus and the posterior limb of the internal capsule can be used to predict the injury of cerebral nuclei and white matter fibers.


Assuntos
Humanos , Recém-Nascido , Anisotropia , Bilirrubina , Encéfalo , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Substância Branca
17.
Journal of Peking University(Health Sciences) ; (6): 341-347, 2020.
Artigo em Chinês | WPRIM | ID: wpr-942185

RESUMO

OBJECTIVE@#To construct and verify a standard template of white matter based on Chinese normal 0 to 2 years old infants by using nonlinear high registration accuracy of non-rigid diffeomorphism paradigm (large deformation diffeomorphic metric mapping, LDDMM).@*METHODS@#Full-term spontaneous labor children without maternal pregnancy disease (hypertension, diabetes, etc.), intrauterine hypoxia and ischemia, head trauma, intracranial infection, intracranial surgery history, family history of mental disorders were selected. Diffusion tensor imaging (DTI) data from the 120 normal Chinese infants under 2 years old were acquired after excluding the existence of neurological diseases revealed by neurologists, radiologists and Gesell Developmental Scale. All the data were divided into six groups including group A: 1 day to 1.5 months, group B: 1.5 to 4.5 months, group C: 4.5 to 9.0 months, group D: 9 to 15 months, group E: 15 to 21 months, and group F: 21 to 24 months. Data pre-processing, normalizing, tensor fitting and calculation of all the images were performed by using MRlcron, DtiStudio, DiffeoMap and SPM software package combined with LDDMM image registration method based on the selected single template of each group. And the average templates of each group were constructed by MATLAB software platform. The set of templates included fractional anisotropy figure (FA), color map, T1 weighted image, b0 image and the mean of all DWfs figures.@*RESULTS@#The templates of FA, T1, b0, DWfs and color map for the normal brain magnetic resonance white matter development of the Chinese infants aged 0 to 2 years were successfully established with the subjective scores exceeding 2 points. The objective evaluation root mean squared error was controlled below 0.19, and the cubic chart of brain alternation trend for the children aged 0 to 2 years was consistent with previous literature.@*CONCLUSION@#Constructing a standard template of white matter based on Chinese normal infants, by using nonlinear high registration accuracy of non-rigid diffeomorphism paradigm provides not only a foundation of further research on brain development, mechanism and treatment of pediatric diseases associated with brain, but also objective and fair imaging information for medical education and research.


Assuntos
Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Encéfalo/diagnóstico por imagem , Imagem de Tensor de Difusão , Processamento de Imagem Assistida por Computador , Espectroscopia de Ressonância Magnética , Software , Substância Branca/diagnóstico por imagem
18.
Rev. argent. radiol ; 83(3): 95-101, set. 2019. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1057407

RESUMO

Objetivo Desde la aparición de la tractografía, al tratarse de una técnica no invasiva y que usa la ampliamente conocida resonancia magnética (RM), el estudio de la sustancia blanca se ha facilitado. A partir de eso, se han logrado grandes descubrimientos en cuanto a fascículos cerebrales involucrados en funciones cognitivas. Sin embargo, su evaluación sigue siendo subjetiva y depende de la experiencia y entrenamiento del evaluador, razón por la cual se ha limitado su aplicabilidad en la práctica clínica. En ese sentido, es conveniente parametrizar volúmenes cerebrales de sustancia blanca en población sana a través de una herramienta electrónica que se pueda reproducir y así poderlo aplicar en enfermos. Materiales y métodos Se reportan 10 sujetos sanos desde el punto de vista neurológico. Para cada sujeto, se adquirieron imágenes ponderadas por difusión y los resultados se visualizaron mediante FiberNavigator (http://scilus.github.io/fibernavigator). Finalmente, esa misma herramienta fue utilizada para purificar los fascículos objeto de estudio y realizar el conteo de las fibras. Resultados Se obtuvieron valores de volumetría del fascículo longitudinal superior (FLS), fascículo longitudinal inferior (FLI), fascículo frontoccipital inferior (FFI), fascículo uncinado (FU) y fascículo del cíngulo (FC), identificando que no existen diferencias estadísticamente significativas entre el número de fibras que componen los fascículos cerebrales. Discusión Los resultados alcanzados de la anatomía y la direccionalidad de fibras de los fascículos cerebrales de este estudio coinciden con el resto de la evidencia publicada hasta el momento, sin encontrar diferencias en cuanto a su organización y recorrido. Conclusión Aunque esos resultados no sirven como valores de referencia para ser aplicados en pacientes con patología neurológica, brindamos información inexistente hasta el momento, con ese equipo en específico y la reproducción entre los distintos usuarios y el software.


Objective Since the appearance of tractography, as it is a non-invasive technique and uses the widely known magnetic resonance (MR), the study of white matter has been facilitated. After this, great discoveries have been made regarding the brain fascicles involved in cognitive functions. However, its evaluation continues to be subjective and depends on the evaluator's experience and training. That the reason why its applicability has been limited in clinical practice. Because of this, it is convenient to parametrize cerebral volumes of white matter in healthy population through an electronic, reproducible tool that could be applied in patients. Materials and Methods Ten neurologically healthy subjects are reported, for each subject we acquired images weighted by diffusion and the results were visualized by means of FiberNavigator (http://scilus.github.io/fibernavigator). Finally, this same tool was used to purify the fascicles under study and perform the fiber count. Results Volumetric values of the upper longitudinal fasciculus, inferior longitudinal fasciculus, inferior frontoccipital fasciculus, uncinated fasciculus and cingulate fasciculus were obtained, identifying that there are not statistically significant differences in the number of fibers that make up the cerebral fascicles. Discussion The results achieved of the anatomical and fiber directionality of the cerebral fascicles of this study, coincide with the rest of the evidence published up to now, without finding differences regarding its organization and route. Conclusion Although these results do not serve as reference values to be applied in patients with neurological pathology, do we provide nonexistent information so far, with this specific equipment and the reproducibility between the different users and the software.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Cognição/fisiologia , Substância Branca/diagnóstico por imagem , Valores de Referência , Anisotropia , Titulometria/normas , Imagem de Tensor de Difusão/normas , Fibras Nervosas
19.
Rev. med. (Säo Paulo) ; 98(4): 259-266, jul.-ago. 2019. ilus
Artigo em Inglês | LILACS | ID: biblio-1023529

RESUMO

It is increasingly recognised that dysfunction in neural circuits plays a key role in the neurobiological basis of mental disorders. The efficacy of pharmacological and behavioural treatments for mental disorders could therefore be improved by targeting dysfunctions in neurocircuits. However, to achieve this, a better understanding of the specific alterations in neural circuits involved in different mental disorders is required. Such understanding can be acquired by using advanced neuroscience methods to examine the pathways and function of neurocircuits in both typically developing individuals and in those with mental disorders. This article provides an overview of currently available neuroscience methods of investigating neural circuits, including advantages and limitations of different techniques, and highlights the importance of using multi-modal imaging in future research.


É cada vez mais reconhecido que a disfunção nos circuitos neurais desempenha um papel fundamental na base neurobiológica dos transtornos mentais. A eficácia dos tratamentos farmacológicos e comportamentais para os transtornos mentais pode, portanto, ser melhorada por direcionar as disfunções nos neurocircuitos. No entanto, para isso, é necessário um melhor entendimento das alterações específicas nos circuitos neurais envolvidos em diferentes transtornos mentais. Tal entendimento pode ser adquirido usando-se métodos avançados de neurociência para examinar as vias e a função dos neurocircuitos em indivíduos com desenvolvimento típico e naqueles com transtornos mentais. Este artigo fornece uma visão geral dos métodos da neurociência atualmente disponíveis na investigação de circuitos neurais, incluindo vantagens e limitações de diferentes técnicas, e destaca a importância do uso de imagens multimodais em pesquisas futuras.


Assuntos
Imageamento por Ressonância Magnética , Eletroencefalografia , Imagem de Tensor de Difusão , Imagem Multimodal , Transtornos Mentais
20.
Rev. argent. neurocir ; 33(2): 73-81, jun. 2019. ilus
Artigo em Espanhol | LILACS, BINACIS | ID: biblio-1177669

RESUMO

Introducción: La estimulación cerebral profunda es una técnica difundida y validada para eltratamiento de múltiples dolencias neurológicas y psiquiátricas, entre ellas el temblor esencial. Objetivo: Evaluar si existe un correlato clínico-anatómico, para un paciente con TE, entre la mejor estimulación lograda y los tractos involucrados. Para esto se realiza una descripción de la técnica utilizada, incluyendo el procesamiento de imágenes necesario. Material y métodos: Se presenta el caso de un paciente de 53 años de edad, con una historia de 23 años de temblor esencial progresivo e incapacitante. Se realizó un implante de DBS bilateral en Vim. Se realizó un post procesamiento de imágenes con un método desarrollado por nuestro equipo a través del cual se permitió evaluar gráficamente el área de estimulación cerebral y sus relaciones con los tractos implicados en la patología (dento-rubro-talámico, haz piramidal y haz lemniscal). Resultados: El paciente presentó una mejoría del 55% medido por escala de temblor de Tolosa. Se obtuvo una correlación anatómica y funcional de lo esperado según imágenes y la respuesta clínica del paciente. Se constataron efectos adversos cuando la estimulación implicaba fibras del haz piramidal y lemniscal, presentando los mejores efectos clínicos cuando el haz dento-rubro-talámico era influenciado por el área de acción del campo eléctrico. Conclusiones: En este reporte mostramos la aplicabilidad de DTI y tractografía para explicar los efectos de la programación de los pacientes con estimulación cerebral profunda.


Introduction: Deep brain stimulation is a widespread and validated technique for the treatment of multiple neurological and psychiatric disorders, including essential tremor. Objective: To evaluate if there is a clinical-anatomical correlate, for a patient with essential tremor, between the best stimulation achieved and the tracts involved. For this, a description of the technique used is made, including the necessary image processing. Methods: We present the case of a 53-year-old patient with a 23-year history of progressive and disabling essential tremor. A bilateral DBS implant was performed on Vim. We performed a post-processing of images with a method developed by our team through which we were able to graphically evaluate the area of brain stimulation and its relationships with the tracts involved in the pathology (dento-rubro-thalamic tract, pyramidal tract and lemniscal tract). Conclusions: In this report we showed the applicability of DTI and tractography to explain the clinical effects of the programming features in patients with deep brain stimulation.


Assuntos
Estimulação Elétrica Nervosa Transcutânea , Tremor Essencial , Imagem de Tensor de Difusão , Transtornos Mentais
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