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1.
Eur Radiol ; 29(3): 1375-1383, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30143836

RESUMO

PURPOSE: Patients with CO intoxication were demonstrated to exhibit white matter (WM) injuries, changes in substantia nigra, dopamine transporter dysfunctions of striatum and Parkinsonism symptoms. We aimed to investigate the relationship between WM injuries of dopaminergic pathways and dopamine transporter dysfunctions of the striatum in patients with acute CO intoxication using both diffusion kurtosis imaging (DKI) and single photon-emission computed tomography (SPECT). MATERIALS AND METHODS: Seventeen patients with acute CO intoxication and 19 age- and gender-matched healthy subjects were enrolled. DKI data were acquired from all participants and Tc-99m-TRODAT-1 SPECT scan was performed on each patient. DKI datasets were fitted to obtain axial, radial and mean diffusivity, fractional anisotropy, axial, radial and mean kurtosis for voxel-based comparison. In addition, the TRODAT-1 binding ratio of the striatum was calculated using the occipital cortices as a reference. In significant regions, correlational analysis was performed to understand the relationship between DKI indices and TRODAT-1 binding ratio. RESULTS: The results showed that DKI indices were significantly altered in multiple WM regions broadly involving the basal ganglia-thalamocortical circuit and nigrostriatal pathway. The correlation analysis further revealed significant correlations between DKI indices and the TRODAT-1 binding ratio in the nigrostriatal pathway (absolute correlation coefficients ranged from 0.5992 to 0.6950, p<0.05), suggesting that CO-induced early WM injuries were associated with dopamine transporter dysfunctions of striatum. CONCLUSION: We concluded that DKI and Tc-99m-TRODAT-1 SPECT scans were helpful in early detection of global WM injuries associated with dysfunctions of dopamine transporter in patients with acute CO intoxication. KEY POINTS: • Voxel-based diffusion kurtosis imaging analysis was helpful in globally detecting early white matter injuries in patients with acute CO intoxication. • CO-induced early white matter injuries were broadly located in basal ganglia-thalamocortical circuit and nigrostriatal pathway. • Early white matter injuries in dopaminergic pathways were significantly correlated with dopamine transporter dysfunctions of the striatum.


Assuntos
Intoxicação por Monóxido de Carbono/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Compostos de Organotecnécio/farmacologia , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tropanos/farmacologia , Substância Branca/diagnóstico por imagem , Doença Aguda , Adulto , Anisotropia , Intoxicação por Monóxido de Carbono/metabolismo , Feminino , Humanos , Masculino , Compostos Radiofarmacêuticos/farmacologia , Substância Branca/metabolismo
2.
J Comput Assist Tomogr ; 41(6): 868-876, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28448418

RESUMO

PURPOSE: Diffusion kurtosis imaging (DKI) has been widely used to characterize brain tissue alterations. Diffusion-weighting factor or b value plays an important role in the measurement of rapid DKI and may have influential effects on them. The purpose of this study was to investigate the effects of b value on rapid DKI indices in normal and acute ischemic brain tissues. MATERIALS AND METHODS: This study enrolled 10 healthy subjects and 4 acute ischemic stroke patients. Three repeated DKI data with 6 high b values (500, 750, 1000, 1500, 2000, 3000 s/mm) were acquired from healthy subjects, whereas nonrepeated DKI data with 3 high b values (1000, 2000, 3000 s/mm) were acquired from ischemic stroke patients. The DKI datasets were decomposed into several rapid DKI datasets consisting of 1 b0 and 2 high b values for comparisons. RESULTS: The results showed that b value significantly impacted the reproducibility and accuracy of DKI indices. The comparisons demonstrated that DKI with b = (0, 1000, 3000) s/mm exhibited more reproducible and accurate DKI indices than other DKI datasets in normal brain tissues, and similar results were noticed in acute ischemic brain tissue. CONCLUSIONS: We concluded that b value significantly impacted the quantification of DKI indices in both normal and acute ischemic brain tissues.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Acidente Vascular Cerebral/diagnóstico por imagem , Isquemia Encefálica/etiologia , Imagem de Difusão por Ressonância Magnética/métodos , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/etiologia , Fatores de Tempo , Adulto Jovem
3.
NMR Biomed ; 29(12): 1739-1747, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27779348

RESUMO

Valine and lactate have been recognized as important metabolic markers to diagnose brain abscess by means of MRS. However, in vivo unambiguous detection and quantification is hampered by macromolecular contamination. In this work, MEGA-PRESS difference editing of valine and lactate is proposed. The method is validated in vitro and applied for quantitative in vivo experiments in one healthy subject and two brain abscess patients. It is demonstrated that with this technique the overlapping lipid signal can be reduced by more than an order of magnitude and thus the robustness of valine and lactate detection in vivo can be enhanced. Quantification of the two abscess MEGA-PRESS spectra yielded valine/lactate concentration ratios of 0.10 and 0.27. These ratios agreed with the concentration ratios determined from concomitantly acquired short-TE PRESS data and were in line with literature values. The quantification accuracy of lactate (as measured with Cramér-Rao lower bounds in LCModel processing) was better for MEGA-PRESS than for short-TE PRESS in all acquired in vivo datasets. The Cramér-Rao lower bounds of valine were only better for MEGA-PRESS in one of the two abscess cases, while in the other case coediting of isoleucine confounded the quantification in the MEGA-PRESS analysis. MEGA-PRESS and short-TE PRESS should be combined for unambiguous quantification of amino acids in abscess measurements. Simultaneous valine/lactate MEGA-PRESS editing might benefit the distinction of brain abscesses from tumors, and further categorization of bacteria with reasonable sensitivity and specificity.


Assuntos
Abscesso Encefálico/metabolismo , Encéfalo/metabolismo , Ácido Láctico/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Imagem Molecular/métodos , Processamento de Sinais Assistido por Computador , Valina/metabolismo , Algoritmos , Biomarcadores/metabolismo , Encéfalo/patologia , Abscesso Encefálico/patologia , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
4.
Eur Radiol ; 25(5): 1413-20, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25465712

RESUMO

OBJECTIVES: To investigate the feasibility of using susceptibility-weighted imaging (SWI) to discriminate abscesses and necrotic tumours. METHODS: Twenty-one patients with pyogenic abscesses, 21 patients with rim-enhancing glioblastomas and 23 patients with rim-enhancing metastases underwent SWI. Intralesional susceptibility signal (ILSS) was analyzed employing both qualitative (QL) and semi-quantitative (SQ) methods. Logistic regression models and receiver operating characteristic analysis were used to demonstrate the discriminating power. RESULTS: In QL analysis, ILSSs were seen in 12 of 21 abscesses, in 20 of 21 glioblastomas, and in 16 of 23 metastases. In SQ analysis, a low degree of ILSS (85.8 %) was in the majority of abscesses and a high degree of ILSS (76.2 %) was in the majority of glioblastomas. SQ model was significantly better than QL model in distinguishing abscesses from glioblastomas (P < .001). A derived ILSS cutoff grade of 1 or less was quantified as having a sensitivity of 85.7 %, specificity of 90.5 %, accuracy of 88.1 %, PPV of 90.0 %, and NPV of 86.4 % in distinguishing abscesses from glioblastomas. CONCLUSIONS: A high-grade ILSS may help distinguish glioblastomas from abscesses and necrotic metastatic brain tumours. The lack of ILSS or low-grade ILSS can be a more specific sign in the imaging diagnosis of abscesses. KEY POINTS: • ILSS of SWI can contribute to differential diagnosis of rim-enhanced mass. • Low-grade ILSS can be a more specific sign in abscesses. • High-grade ILSS may help distinguish necrotic glioblastomas from abscesses. • ILSS spreads across the four ILSS categories in metastases.


Assuntos
Abscesso Encefálico/diagnóstico , Neoplasias Encefálicas/diagnóstico , Encéfalo/patologia , Glioblastoma/diagnóstico , Imageamento por Ressonância Magnética/métodos , Neoplasias Encefálicas/patologia , Diagnóstico Diferencial , Diagnóstico por Imagem , Estudos de Viabilidade , Feminino , Glioblastoma/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Necrose/diagnóstico , Necrose/patologia , Variações Dependentes do Observador , Curva ROC , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
6.
Neuroreport ; 35(10): 621-626, 2024 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-38813903

RESUMO

Age-related macular degeneration (AMD) is a prevalent disease leading to severe visual impairment in the elderly population. Despite this, the pathogenesis of AMD remains largely unexplored. The application of resting-state functional MRI (rs-fMRI) allows for the detection of coherent intrinsic brain activities along with the interactions taking place between the two hemispheres. In the frame of our study, we utilize voxel-mirrored homotopic connectivity (VMHC) as an rs-fMRI method to carry out a comparative analysis of functional homotopy between the two hemispheres with the aim of further understanding the pathogenesis of AMD patients. In our study, we utilized the VMHC method to explore levels of brain activity in individuals diagnosed with AMD, planning to investigate potential links with their clinical characteristics. We extended our invitation to 20 AMD patients and 20 healthy controls from Jiangxi Provincial People's Hospital to participate in this research. rs-fMRIs were captured for each participant, and associated neural activity levels were examined using the VMHC method. Remarkably, our comparative examination with the healthy control group revealed significantly reduced VMHC in the cuneus, superior occipital lobe, precentral gyrus, and superior parietal lobule in the patient cohort. Utilizing the VMHC method allows us to identify discrepancies in the visual pathways of AMD patients compared with standard controls, potentially explaining the common challenges among AMD patients with object recognition, face recognition, and reading.


Assuntos
Degeneração Macular , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Feminino , Degeneração Macular/fisiopatologia , Degeneração Macular/diagnóstico por imagem , Idoso , Pessoa de Meia-Idade , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Mapeamento Encefálico/métodos , Descanso , Lateralidade Funcional/fisiologia
7.
Neuroreport ; 35(11): 702-711, 2024 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-38829952

RESUMO

Thyroid-associated ophthalmopathy (TAO) is a significant autoimmune eye disease known for causing exophthalmos and substantial optic nerve damage. Prior investigations have solely focused on static functional MRI (fMRI) scans of the brain in TAO patients, neglecting the assessment of temporal variations in local brain activity. This study aimed to characterize alterations in dynamic regional homogeneity (dReHo) in TAO patients and differentiate between TAO patients and healthy controls using support vector machine (SVM) classification. Thirty-two patients with TAO and 32 healthy controls underwent resting-state fMRI scans. We calculated dReHo using sliding-window methods to evaluate changes in regional brain activity and compared these findings between the two groups. Subsequently, we employed SVM, a machine learning algorithm, to investigate the potential use of dReHo maps as diagnostic markers for TAO. Compared to healthy controls, individuals with active TAO demonstrated significantly higher dReHo values in the right angular gyrus, left precuneus, right inferior parietal as well as the left superior parietal gyrus. The SVM model demonstrated an accuracy ranging from 65.62 to 68.75% in distinguishing between TAO patients and healthy controls based on dReHo variability in these identified brain regions, with an area under the curve of 0.70 to 0.76. TAO patients showed increased dReHo in default mode network-related brain regions. The accuracy of classifying TAO patients and healthy controls based on dReHo was notably high. These results offer new insights for investigating the pathogenesis and clinical diagnostic classification of individuals with TAO.


Assuntos
Rede de Modo Padrão , Oftalmopatia de Graves , Imageamento por Ressonância Magnética , Máquina de Vetores de Suporte , Humanos , Oftalmopatia de Graves/diagnóstico por imagem , Oftalmopatia de Graves/fisiopatologia , Masculino , Feminino , Imageamento por Ressonância Magnética/métodos , Adulto , Pessoa de Meia-Idade , Rede de Modo Padrão/diagnóstico por imagem , Rede de Modo Padrão/fisiopatologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia
8.
J Neurophysiol ; 109(3): 659-65, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23136342

RESUMO

Recent studies in normal subjects suggested that callosal motor fibers pass through the posterior body of the corpus callosum (CC), but this has not been tested in patients with callosal infarction. The objective of this study is to define the pathways involved in transcallosal inhibition by examining patients with infarctions in different subregions of the CC. We hypothesized that patients with lesions in the posterior one-half of the CC would have greater reduction in transcallosal inhibition between the motor cortices. Twenty-six patients with callosal infarction and 14 healthy subjects were studied. The callosal lesions were localized on sagittal MRI and were attributed to one of five segments of the CC. Transcranial magnetic stimulation was used to assess ipsilateral silent period (iSP) and short- and long-latency interhemispheric inhibition (SIHI and LIHI, respectively) originating from both motor cortices. The results showed that the iSP areas and durations were markedly reduced bilaterally in patients with callosal infarction compared with normal subjects. Patients with callosal infarctions also had less IHI bidirectionally compared with normal subjects. iSP areas and durations were lower in patients with lesions than in patients without lesions in segment 3 (posterior midbody) of the CC. Lesion burden in the posterior one-half of the CC negatively correlated transcallosal inhibition measured with iSP and SIHI. Our study suggests that callosal infarction led to reduced transcallosal inhibition, as measured by iSP, SIHI, and LIHI. Fibers mediating transcallosal inhibition cross the CC mainly in the posterior one-half.


Assuntos
Corpo Caloso/fisiopatologia , Infarto da Artéria Cerebral Anterior/fisiopatologia , Inibição Neural , Idoso , Estudos de Casos e Controles , Corpo Caloso/patologia , Feminino , Humanos , Infarto da Artéria Cerebral Anterior/diagnóstico , Masculino , Córtex Motor/fisiopatologia , Estimulação Magnética Transcraniana
10.
Orbit ; 32(6): 395-8, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24215169

RESUMO

Sparganosis is an infection by the parasitic tapeworm larvae of Spirometra species. Ocular sparganosis is a rare disease that is easily misdiagnosed. We reported a rare case of ocular sparganosis mimicking orbital idiopathic inflammatory syndrome at initial presentation. A 34-year-old female presented with rapid progressive swelling of her left eyelid and mild proptosis for the duration of one month. The other ocular examinations were normal and the thyroid function was normal. Magnetic resonance imaging revealed a fusiform enlargement and mild heterogenous enhancement of the superior oblique muscle of the left orbit. First she received prednisolone therapy and the proptosis partially improved. Six months later, a white, flat and wrinkled string like worm wriggled out from the caruncular conjunctiva of the left eye. The pathology results confirmed that the worm was a Spirometra species larva. After removal of the larva and treatment with praziquantel, the proptosis was resolved without recurrence. Ocular sparganosis is a rare disease and only a few case reports have been reported. The drug therapy has not been effective and the surgical removal is the principal therapy. Despite its rarity, ocular sparganosis should be considered as a possible cause of orbital inflammation in patients.


Assuntos
Infecções Oculares Parasitárias/diagnóstico , Doenças Orbitárias/diagnóstico , Pseudotumor Orbitário/diagnóstico , Esparganose/diagnóstico , Adulto , Animais , Diagnóstico Diferencial , Edema/diagnóstico , Infecções Oculares Parasitárias/parasitologia , Doenças Palpebrais/diagnóstico , Feminino , Humanos , Imageamento por Ressonância Magnética , Doenças Orbitárias/parasitologia , Esparganose/parasitologia , Spirometra/isolamento & purificação , Tomografia Computadorizada por Raios X
11.
J Magn Reson Imaging ; 36(6): 1353-61, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23097197

RESUMO

PURPOSE: To demonstrate the presence of a multilayer appearance of the capsule on contrast-enhanced (CE) susceptibility-weighted imaging (SWI) in patients with pyogenic brain abscesses. Possible origins for the appearance and effects of postprocessing settings are discussed. MATERIALS AND METHODS: Fourteen patients with pyogenic brain abscesses underwent post gadolinium-enhanced SWI at 1.5 T. All SWI images were postprocessed with various filter and mask settings to compare the image appearance. Computer simulations using a paramagnetic spherical shell model were performed to verify the clinical findings. RESULTS: Pyogenic brain abscesses demonstrated a multilayer appearance with a darkened ring within the enhanced capsule on CE-SWI in all patients. The multilayer appearance was slice-orientation-dependent, decreased with larger widths of the high-pass filter, and increased with larger numbers of phase mask multiplication operations, consistently on both simulation results and the clinical images. CONCLUSION: CE-SWI shows the multilayer appearance of the capsule in pyogenic brain abscesses, which may arise from postprocessing procedures originally designed to enhance susceptibility contrast. Although SWI may provide additional information valuable in the diagnosis of pyogenic brain abscesses, image interpretation should be exercised with caution, particularly for CE-SWI.


Assuntos
Algoritmos , Abscesso Encefálico/patologia , Encéfalo/patologia , Gadolínio , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Meios de Contraste , Feminino , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
12.
Acta Neurol Taiwan ; 21(1): 31-4, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22879087

RESUMO

PURPOSE: To emphasize the importance of early recognition and emergent surgery for spontaneous spinal epidural hematoma (SSEH). CASE REPORT: A 61-year-old female presented with sudden onset of severe neck and back pain after finishing worshiping Buddha followed by quadriparesis, sensory deficits below C4 level and sphincter dysfunction. MR imaging demonstrated acute extensive epidural hematoma of cervico-thoracic spinal segments (C2-T7). Idiopathic SSEH was diagnosed and emergent decompressive laminectomy with hematoma evacuation was performed within 12 hours of symptoms onset. Good functional and neurological outcomes were obtained. CONCLUSION: SSEH is a rare but disabling or even fatal entity. Early diagnosis and prompt surgery improve the neurological and functional outcome but still remain a clinical challenge. Relevant physicians should pay attention to the typical symptoms of the rare entity and SSEH should be one of differential diagnoses.


Assuntos
Hematoma Epidural Espinal , Laminectomia , Vértebras Torácicas/cirurgia , Dor nas Costas/etiologia , Feminino , Hematoma Epidural Espinal/complicações , Hematoma Epidural Espinal/patologia , Hematoma Epidural Espinal/cirurgia , Humanos , Pessoa de Meia-Idade , Vértebras Torácicas/diagnóstico por imagem , Tomografia Computadorizada por Raios X
13.
Zhonghua Yan Ke Za Zhi ; 48(6): 524-9, 2012 Jun.
Artigo em Zh | MEDLINE | ID: mdl-22943808

RESUMO

OBJECTIVE: To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Ji'an county of Jiangxi province, China. METHODS: It was a population-based cross-section study. Geographically defined cluster sampling was used in 5402 randomly selected individuals aged ≥ 50 years in 28 clusters in Ji'an from September to November 2006. The survey was preceded by a pilot study where operational methods were refined and quality assurance evaluation was carried out. All participants were enumerated through village registers followed door-to-door visits. Eligible individuals were invited to receive visual acuity measurement and eye examination. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0. Chi-square test was used to investigate the association of age, gender and education with presenting and best corrected visual acuity. RESULTS: Five thousands four hundreds and two individuals were enumerated and 5010 persons were examined, the response rate was 92.74%. Based on the criteria of World Health Organization visual impairment classification in 1973, 78 persons were diagnosed as blindness, 265 persons were diagnosed as moderate and severe visual impairment defined as best corrected visual acuity, the prevalence of blindness and moderate and severe visual impairment were 1.56% and 5.29% respectively. Ninety-four persons were diagnosed as blindness, 726 persons were diagnosed as moderate and severe visual impairment defined as presenting visual acuity, the prevalence of blindness and moderate and severe visual impairment defined as presenting visual acuity was 1.88% and 14.50% respectively. The prevalence of blindness and moderate and severe visual impairment was higher in aged (trend χ(2) = 970.15, P = 0.000), female (χ(2) = 89.81, P = 0.000), and illiterate persons (trend χ(2) = 241.85, P = 0.000). Cataract was still the first leading cause of blindness and visual impairment, the retinal diseases was the second. Un-corrected refractive error also was the main cause of visual impairment. CONCLUSIONS: The prevalence of blindness and moderate and severe visual impairment was higher than other district in China. The first leading cause of blindness and visual impairment is still cataract.


Assuntos
Cegueira/epidemiologia , Baixa Visão/epidemiologia , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Catarata/epidemiologia , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Transtornos da Visão/epidemiologia
14.
Zhonghua Yan Ke Za Zhi ; 48(6): 530-6, 2012 Jun.
Artigo em Zh | MEDLINE | ID: mdl-22943809

RESUMO

OBJECTIVE: To estimate the prevalence of cataract, the outcomes of cataract surgery, cataract surgical coverage rate, cataract blindness social burden rate in Ji'an county of Jiangxi province, China. METHODS: Cluster sampling was used in randomly selected 5010 individuals aged ≥ 50 years in Ji'an county of Jiangxi province. All individuals were received visual acuity and eye examination, including the evaluation of lens status and cataract surgical status by slit lamp biomicroscopy. Data bank was established by Epi-info Software. Statistical analyses were performed using Stata/SE Statistical Software, release 9.0 (Stata Corp, College Station, TX). Confidence intervals and P values (considered significance at the P < 0.05 level) for prevalence of cataract, cataract surgical coverage rate, cataract blindness social burden rate and outcomes of surgery were calculated with adjustment for clustering effects and stratification associated with the sampling design. RESULTS: In 5010 individuals, 1158 cases of cataract were found, the prevalence of cataract was 23.11% among adults aged 50 or above. The prevalence of cataract was higher in the aged, female (P < 0.01). In 99 eyes with cataract surgery, 50.51% and 5.05% of eyes were performed by the modern extra-capsular surgery and phacoemulsification respectively. The rate of intraocular lens implantation was 55.56%. Post-operative presenting and best corrected visual acuity equal to or more than 0.7 was 10.1% and 45.5% of operated eyes respectively. The main causes of the post-operated eyes with worse visual acuity were post-capsular opacity and refractive error. The cataract surgical coverage rate was 32.29%, and the cataract blindness social burden rate was 3.83%. The cataract surgical rate was lower and cataract blindness social burden rate was higher in the aged persons (P < 0.01). CONCLUSIONS: Cataract is the most common eye disease that may lead into blindness and severe visual impairment among older adults aged equal or more than 50 years. The cataract surgical coverage rate is not high but the cataract blindness social burden rate is heavy in Ji'an county. The rate of intraocular lens implantation need increase and the visual outcomes of the surgery should be further improved in the future.


Assuntos
Cegueira/epidemiologia , Extração de Catarata/estatística & dados numéricos , Catarata/epidemiologia , Idoso , Idoso de 80 Anos ou mais , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência
15.
Neuroreport ; 33(9): 386-391, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35594429

RESUMO

BACKGROUND: Age-related macular degeneration (AMD) is the leading cause of visual loss in the developed world and damages the central retina. Growing evidences demonstrated that AMD patients were associated with brain structure changes in visual pathway. However, it remains unknown whether alterations of spontaneous brain activity changes occur in AMD patients. PURPOSE: The purpose of this study was to investigate the effect of central vision loss on spontaneous brain activity in AMD patients. MATERIAL AND METHODS: Seventeen AMD patients and 17 healthy controls (HCs) underwent resting-state MRI scans. The fractional amplitude of low-frequency fluctuations (fALFFs) was applied to investigate the spontaneous brain activity changes in AMD patients. RESULTS: Compared with HC group, AMD patients showed significant decreased fALFF values in the right calcarine/cuneus (brodmann area 17,8) and right superior parietal lobule (brodmann area 7). CONCLUSION: Our results showed that AMD patients had decreased brain activities in the dorsal visual pathway, which offer important insights into the neural mechanisms of central visual field defect in AMD patients.


Assuntos
Mapeamento Encefálico , Degeneração Macular , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico/métodos , Humanos , Degeneração Macular/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Transtornos da Visão , Vias Visuais/diagnóstico por imagem
16.
Front Neurosci ; 16: 833937, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35350559

RESUMO

Background: Comitant exotropia (CE) is a common eye movement disorder, characterized by impaired eye movements and stereoscopic vision. CE patients reportedly exhibit changes in the central nervous system. However, it remains unclear whether large-scale brain network changes occur in CE patients. Purpose: This study investigated the effects of exotropia and stereoscopic vision dysfunction on large-scale brain networks in CE patients via independent component analysis (ICA). Methods: Twenty-eight CE patients (mean age, 15.80 ± 2.46 years) and 27 healthy controls (HCs; mean age, 16.00 ± 2.68 years; closely matched for age, sex, and education) underwent resting-state magnetic resonance imaging. ICA was applied to extract resting-state networks (RSNs) in both groups. Two-sample's t-tests were conducted to investigate intranetwork functional connectivity (FC) within RSNs and interactions among RSNs between the two groups. Results: Compared with the HC group, the CE group showed increased intranetwork FC in the bilateral postcentral gyrus of the sensorimotor network (SMN). The CE group also showed decreased intranetwork FC in the right cerebellum_8 of the cerebellum network (CER), the right superior temporal gyrus of the auditory network (AN), and the right middle occipital gyrus of the visual network (VN). Moreover, functional network connectivity (FNC) analysis showed that CER-AN, SMN-VN, SN-DMN, and DMN-VN connections were significantly altered between the two groups. Conclusion: Comitant exotropia patients had abnormal brain networks related to the CER, SMN, AN, and VN. Our results offer important insights into the neural mechanisms of eye movements and stereoscopic vision dysfunction in CE patients.

17.
Quant Imaging Med Surg ; 12(1): 558-567, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34993101

RESUMO

BACKGROUND: Susceptibility-weighted imaging (SWI) is sensitive to the accumulation of paramagnetic substances, such as hemorrhage and increased venous vasculature, both being frequently found in high-grade tumors. The purpose of this retrospective study is to differentiate high-grade and low-grade astrocytoma by objectively measuring quantitative intra-tumoral susceptibility signals (qITSS) on SWI. METHODS: Precontrast SWI and 3D contrast-enhanced T1WI of 65 patients with astrocytoma were collected at 1.5 Tesla. All tumors were histologically confirmed and classified into two groups: high grade (WHO grade III and IV, n=50) and low grade (WHO grade II, n=15). After manual delineation of the tumor on T1WI, normalized contrast (NC) was calculated voxel by voxel within the tumor by using the concept of contrast to noise ratio. Thresholding on NC was applied to detect qITSS, and the volumetric percentage of qITSS can be obtained for each tumor. Two-sample t-test was applied to examine significant difference of qITSS percentage between high-grade and low-grade astrocytoma for different NC thresholds, ranging from 4 to 20. Receiver operating characteristic analysis was performed to evaluate the performance of differentiation. RESULTS: P value was less than 0.01 for a large range of NC thresholds [4-20], reflecting significant difference of qITSS percentage between high-grade and low-grade astrocytoma. The area under the receiver operating characteristic curve was larger than 0.9 at NC thresholds from 8 to 16 and peaks at 0.949 with a NC threshold of 14. It was shown that astrocytoma grading by qITSS percentage is successful for a wide range of NC threshold, demonstrating robustness on threshold selection. CONCLUSIONS: Without relying on the selection of slice position and at the same time providing objective identification of hypointense signal in SWI, the qITSS percentage can be used to distinguish high-grade and low-grade astrocytoma reliably.

18.
Exp Gerontol ; 151: 111402, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33984449

RESUMO

INTRODUCTION: As populations age, sarcopenia becomes a major health problem among adults aged 65 years and older. However, little information is available about the relationship between sarcopenia and brain structure abnormalities. The objective of this study was to investigate associations between sarcopenia and brain atrophy in older adults and relationships with regional brain areas. METHODS: This prospective cohort study recruited 102 retirement community residents aged 65 years and older. All participants underwent gait speed measurement, handgrip strength measurement and muscle mass measurement by dual X-ray absorptiometry. Diagnosis of sarcopenia was made according to criteria of the Asian Working Group for Sarcopenia (AWGSOP). All patients underwent magnetic resonance imaging (MRI), and images were analysed for global cortical atrophy (GCA) (range 0-3), parietal atrophy (PA) (range 0-3) and medial temporal atrophy (MTA) (range 0-4). RESULTS: Among 102 older adult participants (81.4 ± 8.2 years), 47 (46.1%) were diagnosed with sarcopenia according to AWGSOP criteria. The sarcopenia group had more moderate to severe PA (Grade 2: 19.1% vs. 5.5%; grade 3:6.4% vs. 0%, P = 0.016) and GCA (Grade 2: 40.4% vs. 18.2%, P = 0.003) and a trend of more moderate to severe MTA (Grade 2: 46.8% vs. 30.9%; grade 3: 8.5% vs. 1.8%, P = 0.098) than the non-sarcopenia group. In univariate logistic regression, sarcopenia was significantly associated with PA (OR 5.94, 95% CI 1.56-22.60, P = 0.009), GCA (OR 3.05, 95% CI 1.24-7.51, P = 0.015), and MTA (OR 2.55, 95% CI 1.14-5.69, P = 0.023). In multivariable logistic regression analysis, sarcopenia was an independent risk factor for PA (adjusted OR 6.90, 95% CI 1.30-36.47, P = 0.023). After adjusting for all covariates, only age had a significant relationship with GCA (Adjusted OR 1.09, 95% CI 1.00-1.19, P = 0.044) and MTA (Adjusted OR 1.09, 95% CI 1.01-1.17, P = 0.022). CONCLUSIONS: This is the first study to explore associations between sarcopenia and global as well as regional brain atrophy in older adults. The sarcopenia group had higher rates of moderate to severe PA, GCA and MTA than the non-sarcopenia group. PA was significantly associated with sarcopenia in older adults. Further longitudinal studies are needed to address the mechanism and pathogenesis of brain atrophy and sarcopenia.


Assuntos
Sarcopenia , Idoso , Atrofia , Força da Mão , Humanos , Imageamento por Ressonância Magnética , Estudos Prospectivos , Sarcopenia/epidemiologia
19.
Eur J Radiol ; 126: 108968, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32203827

RESUMO

PURPOSE: Carbon monoxide (CO) intoxication causes gray matter (GM) changes and headache symptom in patients with CO intoxication, but the headache-associated GM changes are not well understood. The purpose of this study was to perform a voxel-based morphometry (VBM) analysis to investigate longitudinal GM changes of brain pain matrix in patients with CO intoxication. METHODS: This prospective study enrolled 24 patients with CO intoxication and 20 healthy controls. Whole brain high-resolution T1-weighted images were acquired in both groups and were repeated in patients at 1 week, and 1, 3, and 9 months after CO exposure. VBM was performed to detect global GM changes in patients with CO intoxication, and the automated anatomical labeling template was utilized to estimate the distribution of significant GM clusters in the brain. RESULTS: GM volumes were significantly decreased mainly in the frontal and occipital lobes, including several pain-matrix regions 1 week after CO intoxication. The regions with significant GM changes further involved the central GM structures and the periaqueductal gray (pain-modulating center) at 1 and 3 months after CO intoxication, but the alterations were partially normalized in the frontal lobe and cerebellum 9 months after CO intoxication. Significant negative correlations were revealed between GM volume and duration of coma in the pain matrix regions. Moreover, five patients exhibited delayed neuropsychiatric sequelae (DNS) and had greater GM volume changes than non-DNS patients. CONCLUSION: VBM analysis is helpful to understand the longitudinal GM changes of the pain matrix in patients with CO intoxication.


Assuntos
Intoxicação por Monóxido de Carbono/fisiopatologia , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Dor/fisiopatologia , Adulto , Intoxicação por Monóxido de Carbono/complicações , Intoxicação por Monóxido de Carbono/psicologia , Feminino , Substância Cinzenta/efeitos dos fármacos , Humanos , Masculino , Estudos Prospectivos
20.
Clin Imaging ; 68: 124-130, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32592973

RESUMO

PURPOSE: To assess the image quality of 80-kVp craniocervical CT angiography (CCCTA) protocol combined with adaptive statistical iterative reconstruction-V (ASIR-V) and low-dose contrast medium (CM). METHODS: A total of 119 patients were randomly divided into three groups. For group A, 120-kVp protocol was followed with 60 ml CM and filtered back projection; for group B, 80-kVp protocol with 60 ml CM and ASIR-V; and for group C, 80-kVp protocol with 45 ml CM and ASIR-V. Both subjective and objective image quality and radiation doses were evaluated. RESULTS: Arterial attenuation, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the head, neck, and shoulder regions were significantly higher in groups B and C compared with group A. Group C yielded significantly better subjective image quality than that observed in groups A and B (both p < .05). As compared with group A, effective radiation dose and the iodine load of group C were reduced by 51.4% and 25%, respectively. CONCLUSIONS: The CCCTA protocol with 80 kVp, ASIR-V, and 45 ml of CM injected at 3 ml/s significantly reduced the radiation dose, iodine load, and iodine delivery rate while providing better subjective and objective image quality, including higher arterial enhancement and a higher SNR and CNR compared with the 120-kVp protocol.


Assuntos
Angiografia por Tomografia Computadorizada , Meios de Contraste , Algoritmos , Humanos , Doses de Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Razão Sinal-Ruído , Tomografia Computadorizada por Raios X
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