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1.
Anal Chem ; 96(5): 1957-1964, 2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38227936

RESUMEN

Understanding the relationship between the surface properties of a single plasmonic nanoparticle and its catalytic performance is critical for developing highly efficient nanocatalysts. In this study, a one-shot dual-detection-based single-molecule super-resolution imaging method in the evanescent field was developed to observe real-time spatiotemporal catalytic activity on a single plasmonic gold nanoparticle (AuNP) surface. The scattering intensity of AuNPs and the fluorescence of resorufin molecules produced on the AuNP surface were obtained simultaneously to investigate the relationship between nanoparticles and catalytic reactions at a single-molecule level. Chemisorbed adsorbates (i.e., catalytic product and resorufin) changed the electron density of individual AuNPs throughout the catalytic cycle, resulting in the fluctuation of the scattering intensity of individual AuNPs, which was attributed to the electron transfer between reactant resazurin molecules and AuNPs. The increase in the electron density of individual AuNPs affected the catalytic reaction rate. Furthermore, sequential mapping of individual catalytic events at the subdiffraction limit resolution was completed for real-time surface dynamics and spatiotemporal activity variations on the single AuNP surface. The developed method can aid in understanding surface-property-dependent catalytic kinetics and facilitate the development of nanoparticle-based heterogeneous catalysts at subdiffraction limit resolution.

2.
Stud Health Technol Inform ; 310: 1538-1539, 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38269734

RESUMEN

The purpose of this study is to develop cloud-based electronic nursing records (ENR) that can be used as Academic-EMR to help students adapt to the clinical field and improve the clarity of nursing records and nursing information capabilities. This research and development are expected to increase the efficiency of nursing work in clinical sites by improving students' access to ENR through the development of various virtual patient contents.


Asunto(s)
Nube Computacional , Estudiantes de Enfermería , Humanos , Registros de Enfermería , Electrónica
3.
PLoS One ; 17(3): e0265671, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35303011

RESUMEN

This study aimed to investigate alterations in white matter (WM) microstructure in patients with psychotic and non-psychotic bipolar disorder (PBD and NPBD, respectively). We used 3T-magnetic resonance imaging to examine 29 PBD, 23 NPBD, and 65 healthy control (HC) subjects. Using tract-based spatial statistics for diffusion tensor imaging data, we compared fractional anisotropy (FA) and mean diffusion (MD) pairwise among the PBD, NPBD, and HC groups. We found several WM areas of decreased FA or increased MD in the PBD and NPBD groups compared to HC. PBD showed widespread FA decreases in the corpus callosum as well as the bilateral internal capsule and fornix. However, NPBD showed local FA decreases in a part of the corpus callosum body as well as in limited regions within the left cerebral hemisphere, including the anterior and posterior corona radiata and the cingulum. In addition, both PBD and NPBD shared widespread MD increases across the posterior corona radiata, cingulum, and sagittal stratum. These findings suggest that widespread WM microstructural alterations might be a common neuroanatomical characteristic of bipolar disorder, regardless of being psychotic or non-psychotic. Particularly, PBD might involve extensive inter-and intra-hemispheric WM connectivity disruptions.


Asunto(s)
Trastorno Bipolar , Sustancia Blanca , Anisotropía , Trastorno Bipolar/diagnóstico por imagen , Trastorno Bipolar/patología , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Imagen de Difusión Tensora/métodos , Humanos , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología
4.
Exp Neurobiol ; 31(6): 401-408, 2022 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-36631848

RESUMEN

Striatal changes in the pathogenesis of Alzheimer's disease (AD) is not fully understood yet. We compared structural and functional image differences in the striatum between patients with early onset AD (EOAD) and late onset AD (LOAD) to investigate whether EOAD harbors autosomal dominant AD like imaging findings. The clinical, neuropsychological and neuroimaging biomarkers of 77 probable AD patients and 107 elderly subjects with normal cognition (NC) from the Alzheimer's Disease Neuroimaging Initiative (ADNI)-2 dataset were analyzed. Enrolled each subject completed a 3-Tesla MRI, baseline 18F-FDG-PET, and baseline 18F-AV-45 (Florbetapir) amyloid PET studies. AD patients were divided into two groups based on the onset age of clinical symptoms (EOAD <65 yrs; LOAD ≥65 yrs). A standardized uptake value ratio of the striatum and subcortical structures was obtained from both amyloid and FDG-PET scans. Structural MR imaging analysis was conducted using a parametric boundary description protocol, SPHARM-PDM. Of the 77 AD patients, 18 were EOAD and 59 were LOAD. Except for age of symptom onset, there were no statistically significant differences between the groups in demographics and detailed neuropsychological test results. 18F-AV-45 amyloid PET showed marked ß-amyloid accumulation in the bilateral caudate nucleus and left pallidum in the EOAD group. Intriguingly, the caudate nucleus and putamen showed maintained glucose metabolism in the EOAD group compared to the LOAD group. Our image findings in the striatum of EOAD patients suggest that sporadic EOAD may share some pathophysiological changes noted in autosomal dominant AD.

5.
Methods Inf Med ; 59(2-03): 86-95, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-33126278

RESUMEN

BACKGROUND: Telepresence robots used to deliver a point-of-care (POC) consultation system that may provide value to enable effective decision making by healthcare providers at care sites. OBJECTIVES: This study aimed to evaluate usability of teleconsultation robots, based on endusers' needs, that can improve acceptance in future robot applications. METHODS: This is a single group postdesign study using mixed methods to assess the usability of teleconsultation robots using scenarios. To collect opinions from various departments, 15 nurses or physicians currently working at medical institutions in Korea were selected using purposive sampling. The usability evaluation was conducted on healthcare providers twice at the simulation center; the think-aloud method was used and surveys and interviews were conducted to identify problems or improvements that may arise from the use of robots in hospital settings. RESULTS: The results showed that perceived usefulness, perceived ease of use, and satisfaction level each scored 4 points or higher out of 7 points, showing usability of midhigh level. Camera angle control and robot driving functions were the most difficult. Other basic robot user interface was shown to be relatively easy. There was no difference in usability depending on the characteristics of the evaluator. Some functions including user interface were modified based on the usability test. CONCLUSION: Using robots in health care institutions may support effective communication among healthcare providers, thus contributing to health care improvement.


Asunto(s)
Consulta Remota , Robótica , Interfaz Usuario-Computador , Humanos , Entrevistas como Asunto , Persona de Mediana Edad , Sistemas de Atención de Punto , Investigación Cualitativa , República de Corea , Encuestas y Cuestionarios , Telemedicina
6.
Clin Psychopharmacol Neurosci ; 18(4): 571-579, 2020 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-33124589

RESUMEN

OBJECTIVE: : This study used network analyses to examine network structures reflecting interactions between specific domains of social functioning in schizophrenia (SZ) and bipolar disorder (BD). METHODS: We used the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) to assess six domains of social functioning ('cognition', 'mobility', 'self-care', 'getting along', 'life activities', and 'participation') in 143 patients with SZ, 81 patients with BD, and 106 healthy subjects. We constructed regularized partial correlation networks, estimated network centrality and edge strength, tested network stability, and compared SZ and BD network structures. RESULTS: Patients with SZ showed a significantly higher level of functional disability than patients with BD. In the networks we constructed, 'cognition' was the most central domain of social functioning in both SZ and BD. The 'cognition' domain was primarily associated with the 'getting along' domain in the SZ network and the 'life activities' domain in the BD network. We found no significant group-level differences in network structures for SZ vs. BD. CONCLUSION: Our results suggest that cognition may play a pivotal role in social functioning in both SZ and BD. In addition, domains of social functioning in SZ and BD have similar network structures despite the higher level of disability in SZ compared to BD.

7.
Psychiatry Investig ; 17(7): 627-635, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32571005

RESUMEN

OBJECTIVE: More recently, attention has turned to the linkage between childhood trauma and emotional dysregulation, but the evidence in bipolar disorder (BD) is limited. To determine neurobiological relationships between childhood trauma, current anxiety, and impulsivity, we investigated cortical volumetric correlates of these clinical factors in BD. METHODS: We studied 36 patients with DSM-5 BD and 29 healthy controls. Childhood trauma, coexisting anxiety, and impulsivity were evaluated with the Korean version-Childhood Trauma Questionnaire (CTQ), the Korean version-Beck Anxiety Inventory (BAI), and the Korean version-Barratt Impulsiveness Scale (BIS). Voxel-based morphometry (VBM) was used to assess gray matter volume (GMV) alterations on the brain magnetic resonance imaging (MRI). Partial correlation analyses were conducted to examine associations between the GMV and each scale in the BD group. RESULTS: Childhood trauma, anxiety, and impulsivity were interrelated in BD. BD patients revealed significant inverse correlations between the GMV in the right precentral gyrus and CTQ scores (r=-0.609, p<0.0003); between the GMV in the left middle frontal gyrus and BAI scores (r=-0.363, p=0.044). Moreover, patients showed similar tendency of negative correlations between the GMV in the right precentral gyrus and BIS scores; between the GMV in the left middle frontal gyrus and CTQ scores. CONCLUSION: The present study provides evidence for a neural basis between childhood trauma and affect regulations in BD. The GMV alterations in multiple frontal lobe areas may represent neurobiological markers for anticipating the course of BD.

8.
PLoS One ; 15(5): e0232826, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32379845

RESUMEN

This study aimed to investigate abnormalities in the gray matter and white matter (GM and WM, respectively) that are shared between schizophrenia (SZ) and bipolar disorder (BD). We used 3T-magnetic resonance imaging to examine patients with SZ, BD, or healthy control (HC) subjects (aged 20-50 years, N = 65 in each group). We generated modulated GM maps through voxel-based morphometry (VBM) for T1-weighted images and skeletonized fractional anisotropy, mean diffusion, and radial diffusivity maps through tract-based special statistics (TBSS) methods for diffusion tensor imaging (DTI) data. These data were analyzed using a generalized linear model with pairwise comparisons between groups with a family-wise error corrected P < 0.017. The VBM analysis revealed widespread decreases in GM volume in SZ compared to HC, but patients with BD showed GM volume deficits limited to the right thalamus and left insular lobe. The TBSS analysis showed alterations of DTI parameters in widespread WM tracts both in SZ and BD patients compared to HC. The two disorders had WM alterations in the corpus callosum, superior longitudinal fasciculus, internal capsule, external capsule, posterior thalamic radiation, and fornix. However, we observed no differences in GM volume or WM integrity between SZ and BD. The study results suggest that GM volume deficits in the thalamus and insular lobe along with widespread disruptions of WM integrity might be the common neural mechanisms underlying the pathologies of SZ and BD.


Asunto(s)
Trastorno Bipolar/patología , Sustancia Gris/patología , Esquizofrenia/patología , Sustancia Blanca/patología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
9.
Psychiatry Investig ; 16(8): 588-593, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31446686

RESUMEN

OBJECTIVE: We aimed to develop predictive models to identify suicide attempters among individuals with suicide ideation using a machine learning algorithm. METHODS: Among 35,116 individuals aged over 19 years from the Korea National Health & Nutrition Examination Survey, we selected 5,773 subjects who reported experiencing suicide ideation and had answered a survey question about suicide attempts. Then, we performed resampling with the Synthetic Minority Over-sampling TEchnique (SMOTE) to obtain data corresponding to 1,324 suicide attempters and 1,330 non-suicide attempters. We randomly assigned the samples to a training set (n=1,858) and a test set (n=796). In the training set, random forest models were trained with features selected through recursive feature elimination with 10-fold cross validation. Subsequently, the fitted model was used to predict suicide attempters in the test set. RESULTS: In the test set, the prediction model achieved very good performance [area under receiver operating characteristic curve (AUC)=0.947] with an accuracy of 88.9%. CONCLUSION: Our results suggest that a machine learning approach can enable the prediction of individuals at high risk of suicide through the integrated analysis of various suicide risk factors.

10.
Neuroimage Clin ; 22: 101805, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30991621

RESUMEN

This study investigated whether resting-state functional connectivity is associated with long-term clinical outcomes of patients with schizophrenia. Resting-state brain images were obtained from 79 outpatients with schizophrenia and 30 healthy controls (HC), using a 3 T-MRI scanner. All patients were 20-50 years old with >3 years' duration of illness and appeared clinically stable. We assessed their psychopathology using the 18-item Brief Psychiatric Rating Scale (BPRS-18) and divided them into "good," "moderate," and "poor" outcome (SZ-GO, SZ-MO, and SZ-PO) groups depending on BPRS-18 total score. We obtained individual functional connectivity maps between a seed region of the bilateral posterior cingulate cortex (PCC) and all other brain regions and compared the functional connectivity of the default mode network (DMN) among the HC and 3 schizophrenia outcome groups, with a voxel-wise threshold of P < .001 within a cluster-extent threshold of 114 voxels. Additionally, we assessed correlations between functional connectivity and BPRS-18 scores. The SZ-MO and SZ-PO groups showed decreased functional connectivity between PCC and right ventromedial prefrontal cortex (vmPFC), left middle cingulate cortex, and left frontopolar cortex (FPC) compared to the SZ-GO and HC groups. DMN connectivity in the right vmPFC and left FPC negatively correlated with subscale scores of the BPRS-18, except the negative symptoms subscale. In this study, poorer clinical outcomes in patients with schizophrenia were associated with decreased DMN connectivity. In particular, the decreased functional connectivity might be related to the severity of positive and mood symptoms rather than negative symptoms.


Asunto(s)
Conectoma , Red Nerviosa/fisiopatología , Evaluación de Resultado en la Atención de Salud , Corteza Prefrontal/fisiopatología , Esquizofrenia/fisiopatología , Índice de Severidad de la Enfermedad , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Red Nerviosa/diagnóstico por imagen , Corteza Prefrontal/diagnóstico por imagen , Esquizofrenia/diagnóstico por imagen
11.
Psychiatry Investig ; 15(11): 1030-1036, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30301301

RESUMEN

OBJECTIVE: In this study, we aimed to develop a model predicting individuals with suicide ideation within a general population using a machine learning algorithm. METHODS: Among 35,116 individuals aged over 19 years from the Korea National Health & Nutrition Examination Survey, we selected 11,628 individuals via random down-sampling. This included 5,814 suicide ideators and the same number of non-suicide ideators. We randomly assigned the subjects to a training set (n=10,466) and a test set (n=1,162). In the training set, a random forest model was trained with 15 features selected with recursive feature elimination via 10-fold cross validation. Subsequently, the fitted model was used to predict suicide ideators in the test set and among the total of 35,116 subjects. All analyses were conducted in R. RESULTS: The prediction model achieved a good performance [area under receiver operating characteristic curve (AUC)=0.85] in the test set and predicted suicide ideators among the total samples with an accuracy of 0.821, sensitivity of 0.836, and specificity of 0.807. CONCLUSION: This study shows the possibility that a machine learning approach can enable screening for suicide risk in the general population. Further work is warranted to increase the accuracy of prediction.

12.
J Alzheimers Dis ; 55(2): 485-495, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27662310

RESUMEN

BACKGROUND: Aging is the most important risk factor of development of dementia in Parkinson's disease (PD), but there are no data on clinical and radiological heterogeneity of PD dementia (PDD) depending on age at onset. OBJECTIVES: The goal of this study was to examine whether patients with PDD are clinically and radiologically heterogeneous depending on age at onset. METHODS: A total of 116 patients with PD dementia and 121 age- and sex-matched normal controls were enrolled. The subjects were divided into early-onset (EOPDD; n = 39) and late-onset (LOPDD; n = 77) PDD with the respective age-matched control group based on a cutoff value of 70 years. The effects of diagnosis, age, and their interaction on neuropsychological tests, cortical thickness, and substantia innominata volume were assessed using analysis of covariance. RESULTS: EOPDD patients had a poorer cognitive performance on digit backward, forward span test (p = 0.011 and 0.05), and visual recognition memory function (p = 0.012) compared with LOPDD patients. Additionally, EOPDD patients exhibited cortical thinning in the left anterior cingulate gyrus and the right inferior temporal gyrus, with significantly decreased normalized substantia innominata volume (p = 0.044). CONCLUSIONS: Our data demonstrated that EOPDD patients exhibit poorer cognitive performance and more severe atrophy in the cortex and substantia innominata, implying that EOPDD may be a distinct phenotype different from LOPDD.


Asunto(s)
Corteza Cerebral/patología , Trastornos del Conocimiento/etiología , Demencia/complicaciones , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/patología , Edad de Inicio , Anciano , Estudios de Casos y Controles , Corteza Cerebral/diagnóstico por imagen , Trastornos del Conocimiento/diagnóstico por imagen , Trastornos del Conocimiento/patología , Demencia/diagnóstico por imagen , Femenino , Radioisótopos de Flúor/metabolismo , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Enfermedad de Parkinson/diagnóstico por imagen , Estadísticas no Paramétricas , Tropanos/metabolismo
13.
Mult Scler ; 22(14): 1850-1858, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-26920380

RESUMEN

OBJECTIVE: To compare the frequency and pattern of cognitive impairment (CI) between patients with neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS). METHODS: A total of 82 NMOSD patients, 58 MS patients, and 45 healthy controls (HCs) underwent a neuropsychological assessment. RESULTS: CI was observed in 29% of NMOSD and 50% of MS patients (p < 0.001); CI was considered present if a patient scored lower than the fifth percentile compared with HCs in at least three domains. A lower frequency of CI was consistently found when CI was indicated by at least two failed tests (p < 0.001). MS patients performed worse than did NMOSD patients on verbal learning and verbal and visual memory tests. Levels of education and depression and the interval from disease onset to treatment were associated with a negative influence on cognition in patients with NMOSD. CONCLUSION: CI in patients with NMOSD may be not as common as in patients with MS. MS patients exhibited severe impairment, particularly on learning and memory tests, compared with NMOSD patients. Differential prevalence and patterns of CI between NMOSD and MS patients suggest that the two diseases have different mechanisms of brain injury.


Asunto(s)
Disfunción Cognitiva/fisiopatología , Esclerosis Múltiple/fisiopatología , Neuromielitis Óptica/fisiopatología , Adulto , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/etiología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Esclerosis Múltiple/complicaciones , Esclerosis Múltiple/diagnóstico por imagen , Esclerosis Múltiple/epidemiología , Neuromielitis Óptica/complicaciones , Neuromielitis Óptica/diagnóstico por imagen , Neuromielitis Óptica/epidemiología
14.
Cerebellum ; 15(2): 174-81, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26062905

RESUMEN

Postmortem studies of essential tremor (ET) have demonstrated the presence of degenerative changes in the cerebellum, and imaging studies have examined related structural changes in the brain. However, their results have not been completely consistent and the number of imaging studies has been limited. We aimed to study cerebellar involvement in ET using MRI segmental volumetric analysis. In addition, a unique feature of this study was that we stratified ET patients into subtypes based on the clinical presence of cerebellar signs and compared their MRI findings. Thirty-nine ET patients and 36 normal healthy controls, matched for age and sex, were enrolled. Cerebellar signs in ET patients were assessed using the clinical tremor rating scale and International Cooperative Ataxia Rating Scale. ET patients were divided into two groups: patients with cerebellar signs (cerebellar-ET) and those without (classic-ET). MRI volumetry was performed using CIVET pipeline software. Data on whole and segmented cerebellar volumes were analyzed using SPSS. While there was a trend for whole cerebellar volume to decrease from controls to classic-ET to cerebellar-ET, this trend was not significant. The volume of several contiguous segments of the cerebellar vermis was reduced in ET patients versus controls. Furthermore, these vermis volumes were reduced in the cerebellar-ET group versus the classic-ET group. The volume of several adjacent segments of the cerebellar vermis was reduced in ET. This effect was more evident in ET patients with clinical signs of cerebellar dysfunction. The presence of tissue atrophy suggests that ET might be a neurodegenerative disease.


Asunto(s)
Vermis Cerebeloso/fisiopatología , Temblor Esencial/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Atrofia/metabolismo , Ataxia Cerebelosa/fisiopatología , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad
15.
Neurodegener Dis ; 15(5): 294-300, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26202063

RESUMEN

BACKGROUND/AIMS: Previous studies indicate that patients with the parkinsonian subtype of multiple system atrophy (MSA-P) experience cognitive impairment. This study aimed to identify the existence of cognitive impairments and the different topographic patterns of morphological changes in MSA-P by means of imaging analysis, and also whether these morphological changes could be associated with cognitive dysfunctions in MSA-P. METHODS: We recruited 15 nondemented probable MSA-P patients and 32 normal controls (NC) for neuropsychological testing and MRI. We analyzed morphological changes using cortical thickness analysis, voxel-based morphometry (VBM) and cerebellar volumetry. Multiple linear regression analysis was performed to evaluate the correlation of each cognitive score with the mean thickness of significant cortical-thinning clusters, mean gray-matter density of VBM clusters and cerebellar volume. RESULTS: The scores on the Digit Span Test, the Seoul Verbal Learning Test (immediate and delayed), the phonemic Controlled Oral Word Association Test and the Stroop color test were significantly lower in the MSA-P group than in the NC group. We found two clusters exhibiting significant cortical thinning in the right paracentral lobule and parahippocampal gyrus. VBM analysis revealed significant gray-matter atrophy in the MSA-P group in the bilateral basal ganglia, cerebellum and temporal and frontal cortical areas. Multiple linear regression analysis demonstrated that cognitive dysfunction correlated significantly with thinning in the neocortex, cerebellum and striatum. CONCLUSIONS: Our data demonstrate that cortical and cerebellar atrophy and striatal degeneration are associated with cognitive impairment in patients with MSA-P.


Asunto(s)
Encéfalo/patología , Trastornos del Conocimiento/etiología , Atrofia de Múltiples Sistemas/patología , Atrofia de Múltiples Sistemas/psicología , Trastornos Parkinsonianos/patología , Trastornos Parkinsonianos/psicología , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Atrofia de Múltiples Sistemas/complicaciones , Pruebas Neuropsicológicas , Trastornos Parkinsonianos/complicaciones
16.
Comput Math Methods Med ; 2015: 167489, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26060504

RESUMEN

While segmentation of the cerebellum is an indispensable step in many studies, its contrast is not clear because of the adjacent cerebrospinal fluid, meninges, and cerebra peduncle. Thus, various cerebellar segmentation methods, such as a deformable model or a template-based algorithm might exhibit incorrect segmentation of the venous sinuses and the cerebellar peduncle. In this study, we propose a fully automated procedure combining cerebellar tissue classification, a template-based approach, and morphological operations sequentially. The cerebellar region was defined approximately by removing the cerebral region from the brain mask. Then, the noncerebellar region was trimmed using a morphological operator and the brain-stem atlas was aligned to the individual brain to define the brain-stem area. The proposed method was validated with the well-known FreeSurfer and ITK-SNAP packages using the dice similarity index and recall and precision scores. As a result, the proposed method was significantly better than the other methods for the dice similarity index (0.93, FreeSurfer: 0.92, ITK-SNAP: 0.87) and precision (0.95, FreeSurfer: 0.90, ITK-SNAP: 0.93). Therefore, it could be said that the proposed method yielded a robust and accurate segmentation result. Moreover, additional postprocessing with the brain-stem atlas could improve its result.


Asunto(s)
Cerebelo/anatomía & histología , Interpretación de Imagen Asistida por Computador/métodos , Adulto , Algoritmos , Encéfalo/anatomía & histología , Encéfalo/fisiología , Mapeo Encefálico , Cerebelo/fisiología , Biología Computacional , Bases de Datos Factuales/estadística & datos numéricos , Femenino , Humanos , Imagen por Resonancia Magnética/estadística & datos numéricos , Masculino , Modelos Anatómicos , Modelos Neurológicos , Adulto Joven
17.
PLoS One ; 8(12): e84054, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24358327

RESUMEN

BACKGROUND: Recent studies have suggested that essential tremor (ET) is a more complex and heterogeneous clinical entity than initially thought. In the present study, we assessed the pattern of cortical thickness and diffusion tensor white matter (WM) changes in patients with ET according to the response to propranolol to explore the pathogenesis underlying the clinical heterogeneity of ET. METHODS: A total of 32 patients with drug naive ET were recruited prospectively from the Movement Disorders outpatient clinic. The patients were divided into a propranolol-responder group (n = 18) and a non-responder group (n = 14). We analyzed the pattern of cortical thickness and diffusion tensor WM changes between these two groups and performed correlation analysis between imaging and clinical parameters. RESULTS: There were no significant differences in demographic characteristics, general cognition, or results of detailed neuropsychological tests between the groups. The non-responder group showed more severe cortical atrophy in the left orbitofrontal cortex and right temporal cortex relative to responders. However, the responders exhibited significantly lower fractional anisotropy values in the bilateral frontal, corpus callosal, and right parietotemporal WM compared with the non-responder group. There were no significant clusters where the cortical thickness or WM alterations were significantly correlated with initial tremor severity or disease duration. CONCLUSIONS: The present data suggest that patients with ET have heterogeneous cortical thinning and WM alteration with respect to responsiveness to propranolol, suggesting that propranolol responsiveness may be a predictive factor to determine ET subtypes in terms of neuroanatomical heterogeneity.


Asunto(s)
Corteza Cerebral/patología , Imagen de Difusión Tensora , Temblor Esencial/patología , Temblor Esencial/fisiopatología , Antagonistas Adrenérgicos beta/uso terapéutico , Anciano , Anisotropía , Corteza Cerebral/efectos de los fármacos , Temblor Esencial/diagnóstico , Temblor Esencial/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Pronóstico , Propranolol/uso terapéutico , Resultado del Tratamiento
18.
Parkinsonism Relat Disord ; 19(11): 970-4, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23867866

RESUMEN

BACKGROUND AND PURPOSE: Despite the predominant degeneration of subcortical structures, recent studies have suggested the evidence of cortical involvement in multiple system atrophy (MSA). This study aimed to identify the different topographic pattern of cortical thinning in MSA according to clinical subtypes, and the association of cortical thinning with cerebellar atrophy and other disease related metrics. MATERIALS AND METHODS: We used cortical thickness analysis in 53 non-demented probable MSA patients (29 with MSA-C, 24 with MSA-P) and 35 healthy subjects and modeled local cortical thickness as a linear association with cerebellar volume and disease related metrics including age, disease duration, cognition and disease severity. RESULTS: We found five clusters (left ventromedial prefrontal, bilateral ventrolateral prefrontal cortex, right parahippocampal and lingual gyrus) exhibiting significant cortical thinning in MSA-C and two clusters (right primary sensory motor and left ventromedial prefrontal cortex) exhibiting a thinning tendency in MSA-P compared with the control group. In correlation analysis, we identified no cluster exhibiting a significant correlation with cerebellar atrophy in both of the MSA groups. However, cortical thickness in right parahippocampalgyrus and left ventrolateral prefrontal cortex showed significant negative correlation with International Cooperative Ataxia Rating Scale subscore of speech disorder in MSA-C group. CONCLUSIONS: We identified different topographic distributions of cortical thinning in MSA subtypes. Our study suggests that cortical thinning of MSA occurs independently of cerebellar atrophy as a primary disease process rather than secondary deafferentation.


Asunto(s)
Mapeo Encefálico/métodos , Corteza Cerebral/patología , Atrofia de Múltiples Sistemas/clasificación , Atrofia de Múltiples Sistemas/diagnóstico , Anciano , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad
19.
Magn Reson Imaging ; 31(7): 1190-6, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23684964

RESUMEN

The hippocampus has been known to be an important structure as a biomarker for Alzheimer's disease (AD) and other neurological and psychiatric diseases. However, it requires accurate, robust and reproducible delineation of hippocampal structures. In this study, an automated hippocampal segmentation method based on a graph-cuts algorithm combined with atlas-based segmentation and morphological opening was proposed. First of all, the atlas-based segmentation was applied to define initial hippocampal region for a priori information on graph-cuts. The definition of initial seeds was further elaborated by incorporating estimation of partial volume probabilities at each voxel. Finally, morphological opening was applied to reduce false positive of the result processed by graph-cuts. In the experiments with twenty-seven healthy normal subjects, the proposed method showed more reliable results (similarity index=0.81±0.03) than the conventional atlas-based segmentation method (0.72±0.04). Also as for segmentation accuracy which is measured in terms of the ratios of false positive and false negative, the proposed method (precision=0.76±0.04, recall=0.86±0.05) produced lower ratios than the conventional methods (0.73±0.05, 0.72±0.06) demonstrating its plausibility for accurate, robust and reliable segmentation of hippocampus.


Asunto(s)
Enfermedad de Alzheimer/patología , Mapeo Encefálico/métodos , Hipocampo/patología , Anciano , Algoritmos , Automatización , Reacciones Falso Positivas , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Persona de Mediana Edad , Reconocimiento de Normas Patrones Automatizadas/métodos , Probabilidad , Reproducibilidad de los Resultados
20.
Arch Otolaryngol Head Neck Surg ; 136(6): 610-5, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20566913

RESUMEN

OBJECTIVES: To compare the volume of the maxillary sinus, dental factors, and craniofacial anatomical features between control subjects and patients with chronic rhinosinusitis (CRS) and to investigate critical factors for the volumetric change in the maxillary sinus in adults. DESIGN: Retrospective case-control study. SETTING: Tertiary referral center. PARTICIPANTS: Ninety-nine individuals who visited an allergy and sinus center: 52 control subjects (septal deviation; mean age, 32.69 years) and 47 patients with CRS (mean age, 44.43 years). INTERVENTION: Cephalometry and computed tomography were performed in all the participants. In blinded tests, dentists investigated the dental status of both groups. MAIN OUTCOME MEASURES: Maxillary sinus: bone thickness and volume on computed tomography; craniofacial anatomical features: linear and angular variables in lateral cephalometry; and dental evaluation: malocclusion class, teeth status, and alveolar bone height. RESULTS: Bony wall thickness of the maxillary sinus significantly increased in patients with CRS (P < .001) but showed no relationship with maxillary sinus volume. Maxillary sinus volume significantly decreased in patients with CRS (P = .001). Age and alveolar bone height had a negative effect on maxillary sinus volume in both groups. Abnormal teeth had no relationship with maxillary sinus volume in both groups but showed a negative effect on alveolar bone height in the CRS group (P = .02). Class II malocclusion associated with anterior movement of the maxilla significantly increased in the CRS group (P = .006). CONCLUSIONS: Regardless of CRS, maxillary sinus volume decreased with older age and increased with alveolar bone loss. Regarding craniofacial anatomical features, CRS may have an effect on malocclusion in adults.


Asunto(s)
Cara/anatomía & histología , Seno Maxilar/patología , Rinitis/patología , Sinusitis/patología , Cráneo/anatomía & histología , Adulto , Cefalometría , Enfermedad Crónica , Humanos , Maloclusión Clase II de Angle/patología , Tamaño de los Órganos , Estudios Retrospectivos , Tomografía Computarizada por Rayos X
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