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1.
Small ; : e2405635, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39344596

RESUMEN

The increasing incidence of serious bacterial keratitis, a sight-threatening condition often exacerbated by inadequate contact lens (CLs) care, highlights the need for innovative protective technology. This study introduces a long-lasting antibacterial, non-cytotoxic, transparent nanocoating for CLs via a solvent-free polymer deposition method, aiming to prevent bacterial keratitis. The nanocoating comprises stacked polymer films, with poly(dimethylaminomethyl styrene-co-ethylene glycol dimethacrylate) (pDE) as a biocompatible, antibacterial layer atop poly(2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane) (pV4D4) as an adhesion-promoting layer. The pD6E1-grafted (g)-pV4D4 film shows non-cytotoxicity toward two human cell lines and antibacterial activity of >99% against four bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), an antibiotic-resistant bacteria and Pseudomonas aeruginosa, which causes ocular diseases. Additionally, the film demonstrates long-lasting antibacterial activity greater than 96% against MRSA for 9 weeks in phosphate-buffered saline. To the best knowledge, this duration represents the longest reported long-term stability with less than 5% decay of antibacterial performance among contact-killing antibacterial coatings. The film exhibits exceptional mechanical durability, retaining its antibacterial activity even after 15 washing cycles. The pD6E1-g-pV4D4-coated CL maintains full optical transmittance compared to that of pristine CL. It is expected that the unprecedentedly prolonged antibacterial performance of the coating will significantly alleviate the risk of infection for long-term CL users.

2.
Int J Mol Sci ; 24(2)2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36674802

RESUMEN

Uncovering region-specific changes in the myopic retina can provide clues to the pathogenesis of myopia progression. After imposing form deprivation myopia in the right eye of 6-week-old rabbits, we investigated the proteome profile of each retinal region (central, mid-periphery, and far-periphery retina), using accurate high-resolution mass spectrometry. Protein expression was analyzed using gene ontology and network analysis compared with that of the control, the left eyes. Among 2065 proteins detected from whole retinal samples, 249 differentially expressed proteins (DEPs) were identified: 164 DEPs in the far-periphery, 39 in the mid-periphery, and 83 in the central retina. In network analysis, the far-periphery retina showed the most significant connectivity between DEPs. The regulation of coagulation was the most significant biological process in upregulated DEPs in the far-periphery retina. Proteasome was the most significant Kyoto Encyclopedia of Genes and Genomes pathway in downregulated DEPs in the central retina. Antithrombin-III, fibrinogen gamma chain, and fibrinogen beta chain were identified as hub proteins for myopia progression, which were upregulated in the far-periphery retina. Proteomic analysis in this study suggested that oxidative stress can be the primary pathogenesis of myopia progression and that the far-periphery retina plays a role as the key responder.


Asunto(s)
Miopía , Proteoma , Animales , Conejos , Proteoma/metabolismo , Proteómica/métodos , Retina/metabolismo , Miopía/patología , Espectrometría de Masas en Tándem
3.
Opt Express ; 24(10): 10777-85, 2016 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-27409898

RESUMEN

We demonstrate an advanced structure for optical interconnect consisting of 4 channel × 10 Gb/s bidirectional optical subassembly (BOSA) formed using silicon optical bench (SiOB) with tapered fiber guiding holes (TFGHs) for precise and passive optical alignment of vertical-cavity surface-emitting laser (VCSEL)-to-multi mode fiber (MMF) and MMF-to-photodiode (PD). The co-planar waveguide (CPW) transmission line (Tline) was formed on the backside of silicon substrate to reduce the insertion loss of electrical data signal. The 4 channel VCSEL and PD array are attached at the end of CPW Tline using a flip-chip bonder and solder pad. The 12-channel ribbon fiber is simply inserted into the TFGHs of SiOB and is passively aligned to the VCSEL and PD in which no additional coupling optics are required. The fabricated BOSA shows high coupling efficiency and good performance with the clearly open eye patterns and a very low bit error rate of less than 10-12 order at a data rate of 10 Gb/s with a PRBS pattern of 231-1.

4.
Sci Rep ; 14(1): 24072, 2024 10 14.
Artículo en Inglés | MEDLINE | ID: mdl-39402218

RESUMEN

The prevalence of myopia is rapidly increasing, significantly impacting the quality of life of affected individuals. Prior research by our group revealed reactive gliosis in Müller cells within myopic retina, prompting further investigation of their role in myopia, which remains unclear. In this study, we analyzed protein expression changes in CD29+ Müller cells isolated from a form deprivation-induced rabbit model of myopia using magnetic activated cell sorting to investigate the role of these cells in myopia. As the principal glial cells in the retina, Müller cells exhibited significant alterations in the components of metabolic pathways, particularly glycolysis and angiogenesis, including the upregulation of glycolytic enzymes, such as lactate dehydrogenase A and pyruvate kinase, implicated in the adaptation to increased metabolic demands under myopic stress. Additionally, a decrease in the expression of proteins associated with oxygen transport suggested enhanced vulnerability to oxidative stress. These findings highlight the proactive role of CD29+ Müller cells in modifying the retinal environment in response to myopic stress and provide valuable insights into mechanisms that could help mitigate myopia progression.


Asunto(s)
Modelos Animales de Enfermedad , Células Ependimogliales , Miopía , Proteómica , Animales , Conejos , Miopía/metabolismo , Miopía/patología , Células Ependimogliales/metabolismo , Células Ependimogliales/patología , Proteómica/métodos , Retina/metabolismo , Retina/patología , Glucólisis , Estrés Oxidativo , Reprogramación Metabólica
5.
J Taibah Univ Med Sci ; 16(3): 307-317, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34140856

RESUMEN

OBJECTIVE: This study examines the changes in metaphors used by medical students before and after the dissection of a cadaver. This will help qualitatively understand the meaning of cadaver dissections. METHODS: The metaphorical expressions about the practice of dissection that were used before and after the dissection exercises were collected from 147 Korean medical students. The collected qualitative data were categorised through a repeated comparative analysis. RESULTS: The results of the analysis identified seven types of metaphors that were used before the dissection practice: 'rite of passage', 'first step', 'precious opportunity', 'fog', 'hell', 'thrill', and 'double-edged sword'. After the cadaver dissection, nine types of metaphors were used: 'introspection', 'hell', 'precious opportunity', 'treasure hunt', 'turning point', 'debt', 'mist', 'bittersweet candy', and 'buzzer beater'. In general, before a cadaver dissection, students recognised the importance of the practice of cadaver dissection as being a 'gateway' or a 'growing pain'. Metaphors such as 'introspection' and 'mirror' were used with an improved attitude. However, some students continued to use negative metaphors, such as 'hell', before and after the cadaver dissection and maintained negative feelings about it. CONCLUSIONS: The results of our study suggest that, for many medical students, cadaver dissection is a crucial stage of self-reflection and for the formation of their identities as doctors. The consideration of students' perceptions during all cadaver dissections is therefore essential.

6.
J Korean Neurosurg Soc ; 64(1): 69-77, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33105534

RESUMEN

OBJECTIVE: Classification systems for cervical ossification of the posterior longitudinal ligament (OPLL) have traditionally focused on the morphological characteristics of ossification. Although the classification describes many clinical features associated with the shape of the ossification, including the concept of spondylosis seems necessary because of the similarity in age distribution. METHODS: Patients diagnosed with OPLL who presented with increase signal intensity (ISI) on magnetic resonance imaging were surgically treated in our department. The patients were divided into two groups (pure versus degenerative) according to the presence of disc degeneration. RESULTS: Of 141 patients enrolled in this study, more than half (61%) were classified into the degenerative group. The pure group showed a profound male predominance, early presentation of myelopathy, and a different predilection for ISI compared to the degenerative group. The mean canal compromise ratio (CC) of the ISI was 47% in the degenerative group versus 61% in the pure group (p<0.0000). On the contrary, the global and segment motions were significantly larger in the degenerative group (p<0.0000 and p=0.003, respectively). The canal diameters and global angles did not differ between groups. CONCLUSION: Classifying cervical OPLL based on the presence of combined disc degeneration is beneficial for understanding the disorder's behavior. CC appears to be the main factor in the development of myelopathy in the pure group, whereas additional dynamic factors appear to affect its development in the degenerative group.

7.
Front Cell Dev Biol ; 8: 602097, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33324650

RESUMEN

Particulate matter (PM) is a general atmospheric pollutant released into the air by an anthropogenic and naturally derived mixture of substances. Current studies indicate that fine dust can result in different health defects, including endothelial dysfunction, asthma, lung cancer, cardiovascular diseases, uterine leiomyoma, deterioration in sperm quality, and overall birth impairment. However, the most prominent effects of PM10 (diameter < 10 µM) exposure on the female reproductive system, especially with respect to oocyte maturation, remain unclear. In the present study, maturing mouse oocytes were treated with PM10 and the phenotypes of the resulting toxic effects were investigated. Exposure to PM10 led to impairment of maturation capacity by inducing cell cycle arrest and blocking normal polar body extrusion during in vitro maturation and activation of fertilization of mouse oocytes. Additionally, defects in tubulin formation and DNA alignment were observed in PM10-treated oocytes during metaphase I to anaphase/telophase I transition. Moreover, PM10 induced reactive oxygen species generation, mitochondrial dysfunction, DNA damage, and early apoptosis. Taken together, these results indicate that PM10 exposure leads to a decline in oocyte quality and affects the subsequent embryonic development potential of mammalian oocytes.

8.
Exp Mol Med ; 41(3): 189-200, 2009 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-19293638

RESUMEN

Protein phosphatase-1 (PP1) nuclear targeting subunit (PNUTS), also called PP1R10, p99, or CAT 53 was originally isolated as a mammalian nuclear PP1-binding protein. In this study, we performed yeast two-hybrid screens to identify PNUTS-interacting proteins. Here, we report that LCP1 (epidermal Langerhans cell protein 1), a novel member of the HMG-box protein family, binds tightly to PNUTS. Co-immunoprecipitation of deletion constructs revealed that the C-terminus of LCP1 is sufficient for the interaction with an N-terminal region of PNUTS that is distinct from its PP1-binding domain. Furthermore, immunofluorescence studies showed that a subpopulation of LCP1 co-localizes with PNUTS in nuclear speckles. Importantly, we found that the N-terminus of LCP1 has a strong trans-activation activity in a GAL4-based heterologous transcription assay. The transcriptional activity of LCP1 is markedly suppressed by its interaction with PNUTS, in a PP1-independent manner. These findings suggest that the coordinated spatial and temporal regulation of LCP1 and PNUTS may be a novel mechanism to control the expression of genes that are critical for certain physiological and pathological processes.


Asunto(s)
Núcleo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas HMGB/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Unión al ARN/metabolismo , Secuencia de Aminoácidos , Línea Celular , Humanos , Datos de Secuencia Molecular , Unión Proteica , Mapeo de Interacción de Proteínas , Activación Transcripcional , Técnicas del Sistema de Dos Híbridos
9.
Brain Cogn ; 69(2): 391-7, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18848743

RESUMEN

The aim of the present study is to investigate the learning-related changes in brain activation induced by the training of hypothesis generation skills regarding biological phenomena. Eighteen undergraduate participants were scanned twice with functional magnetic resonance imaging (fMRI) before and after training over a period of 2 months. The experimental group underwent eight biological hypothesis generation training programs, but the control group was not given any during the 2-month period. The results showed that the left frontal gyri, the cingulate gyrus, and the cuneus were activated during hypothesis generation. In addition, the brain activation of the trained group increased in the left inferior and the superior frontal gyri, which are related to working memory load and higher-order inferential processes. However, the activation after training decreased in the occipito-parietal route, which is associated with the perception and the analysis processes of visual information. Furthermore, the results have suggested that the dorsolateral prefrontal cortex (DLPFC) region is the critical area in the training of hypothesis generation skills.


Asunto(s)
Encéfalo/fisiología , Cognición/fisiología , Aprendizaje/fisiología , Adulto , Análisis de Varianza , Mapeo Encefálico , Femenino , Lóbulo Frontal/fisiología , Giro del Cíngulo/fisiología , Humanos , Imagenología Tridimensional , Imagen por Resonancia Magnética , Lóbulo Occipital/fisiología , Adulto Joven
10.
In Vivo ; 33(4): 999-1010, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31280188

RESUMEN

Infrastructure in animal husbandry refers to fundamental facilities and services necessary for better living conditions of animals and its economy to function through better productivity. Mainly, infrastructure can be divided into two categories: hard infrastructure and soft infrastructure. Physical infrastructure, such as buildings, roads, and water supplying systems, belongs to hard infrastructure. Soft infrastructure includes services which are required to maintain economic, health, cultural and social standards of animal husbandry. Therefore, the proper management of infrastructure in animal husbandry is necessary for animal welfare and its economy. Among various technologies to improve the quality of infrastructure, non-thermal plasma (NTP) technology is an effectively applicable technology in different stages of animal husbandry. NTP is mainly helpful in maintaining better health conditions of animals in several ways via decontamination from microorganisms present in air, water, food, instruments and surfaces of animal farming systems. Furthermore, NTP is used in the treatment of waste water, vaccine production, wound healing in animals, odor-free ventilation, and packaging of animal food or animal products. This review summarizes the recent studies of NTP which can be related to the infrastructure in animal husbandry.


Asunto(s)
Crianza de Animales Domésticos , Gases em Plasma , Contaminación del Aire , Alimentación Animal , Bienestar del Animal , Animales , Animales Domésticos , Ambiente Controlado , Agua/análisis , Agua/química , Microbiología del Agua
11.
Korean J Med Educ ; 30(4): 317-326, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30522260

RESUMEN

PURPOSE: The study examines changes in students' self-assessment of their general communication (GC) and medical communication (MC) competencies, as well as perceptions of MC concepts. METHODS: Participants included 108 second year medical students enrolled at a Korean medical school studying an MC curriculum. It was divided into three sections, and participants responded to questionnaires before and after completing each section. To assess perceived GC and MC competency, items based on a 7-point Likert scale were employed; a single open-ended item was used to examine students' perceptions of MC. Statistical analysis was conducted to gauge GC and MC competency, whereas semantic network analysis was used to investigate students' perceptions of MC. RESULTS: Students perceived their GC competency to be higher than MC. Perceived MC competency differed significantly across the three sections, whereas no differences were found for GC. There were no statistically significant differences after completing the curriculum's second and third sections; however, the vocabulary students used to describe MC concepts became more scholarly and professional. In the semantic networks, the link structure between MC-related words decreased in linearity and looseness, becoming more complex and clustered. The words 'information' and 'transfer' proved integral to students' perceptions; likewise, 'empathy' and 'communication' became closely connected in a single community from two independent communities. CONCLUSION: This study differed from prior research by conducting an in-depth analysis of changes in students' perceptions of MC, and its findings can be used to guide curriculum development.


Asunto(s)
Comunicación , Curriculum , Educación de Pregrado en Medicina , Competencia Profesional , Facultades de Medicina , Autoevaluación (Psicología) , Estudiantes de Medicina , Empatía , Femenino , Humanos , Difusión de la Información , Masculino , Percepción , República de Corea , Encuestas y Cuestionarios
12.
Korean J Med Educ ; 27(4): 291-300, 2015 Dec.
Artículo en Coreano | MEDLINE | ID: mdl-26657551

RESUMEN

PURPOSE: The purpose of this study is to analyze the differences in the perception of the "good doctor" image between faculty and students, based on the competencies of the "Korean doctor's role." METHODS: The study sample comprised 418 students and 49 faculty members in medical school. They were asked to draw images of a "good doctor," and the competencies were then analyzed using the Draw-A-Scientist test and the social network program Netminer 4.0. RESULTS: Of the competency areas, "communication and collaboration with patient" and "medical knowledge and clinical skills" were the most frequently expressed, and "education and research," "professionalism," and "social accountability" were less commonly expressed. Images of a good doctor by the faculty focused on competencies that were directly related to current clinical doctors. Conversely, those by the students expressed various competencies equally. CONCLUSION: We have provided basic data for faculties and schools to plan various education strategies to help students establish the image of a good doctor and develop the necessary competencies as physicians.


Asunto(s)
Competencia Clínica/normas , Docentes/psicología , Percepción , Rol del Médico/psicología , Estudiantes de Medicina/psicología , Minería de Datos , Humanos , República de Corea , Facultades de Medicina , Estadística como Asunto
13.
J Korean Neurosurg Soc ; 58(3): 242-7, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26539268

RESUMEN

OBJECTIVE: The purpose of this study is to determine whether the changes of contralateral sensorimotor cortical activation on functional magnetic resonance imaging (fMRI) can predict the neurological outcome among spinal cord injury (SCI) patients when the great toes are stimulated without notice. METHODS: This study enrolled a total of 49 patients with SCI and investigated each patient's preoperative fMRI, postoperative fMRI, American Spinal Injury Association (ASIA) score, and neuropathic pain occurrence. Patients were classified into 3 groups according to the change of blood oxygenation level dependent (BOLD) response on perioperative fMRI during proprioceptive stimulation with repetitive passive toe movements : 1) patients with a response of contralateral sensorimotor cortical activation in fMRI were categorized; 2) patients with a response in other regions; and 3) patients with no response. Correlation between the result of fMRI and each parameter was analyzed. RESULTS: In fMRI data, ASIA score was likely to show greater improvement in patients in group A compared to those belonging to group B or C (p<0.001). No statistical significance was observed between the result of fMRI and neuropathic pain (p=0.709). However, increase in neuropathic pain in response to the signal change of the ipsilateral frontal lobe on fMRI was statistically significant (p=0.030). CONCLUSION: When there was change of BOLD response at the contralateral sensorimotor cortex on perioperative fMRI after surgery, relief of neurological symptoms was highly likely for traumatic SCI patients. In addition, development of neuropathic pain was likely to occur when there was change of BOLD response at ipsilateral frontal lobe.

14.
Korean J Spine ; 12(2): 84-7, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26217388

RESUMEN

Grisel's syndrome is a non-traumatic subluxation of the atlantoaxial joints, which is caused by an inflammatory process in the upper neck. It is rare to find literary reports of Grisel's syndrome with an evident pathogen in a lesion. For the first time in Korea, we report a 36-year-old female with Grisel's syndrome having an atlantoaxial subluxation, which was caused by a retropharyngeal abscess secondary to pulmonary Mycobacterium tuberculosis. The patient was treated with an anti-tuberculosis regimen and was prescribed a Philadelphia collar for the control of torticollis. The result of magnetic resonance imaging (MRI) showed an improved atlantoaxial alignment, after drug treatment and immobilization. This patient was neurologically intact and free from symptomatic complaints at follow-up visit. Dynamic cervical radiograph confirmed that the atlantoaxial joints had been stable. The pathophysiology of Grisel's syndrome, along with anatomical attributes, was explained on the basis of the patient's clinical course.

15.
Case Rep Otolaryngol ; 2014: 217349, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25165592

RESUMEN

Intraosseous hemangiomas account for 1% of all bone tumors and primarily originate from the vertebral column and skull bones. However, intraosseous hemangiomas of the nasal cavity are extremely rare. Here, we report a case of intraosseous hemangioma with a cavernous pattern arising from the middle turbinate that was preoperatively misdiagnosed as chronic rhinosinusitis with polyps. Except for nasal obstruction, there were no specific rhinologic symptoms. The tumor was excised en bloc by the endoscopic endonasal approach without preoperative embolization.

16.
Neuroimage ; 37(4): 1132-7, 2007 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-17689105

RESUMEN

Visual assessment of structural MRI is, by definition, normal in patients with juvenile myoclonic epilepsy (JME), a major subsyndrome of idiopathic generalized epilepsy (IGE). However, recent quantitative MRI studies have shown structural abnormalities in cortical and thalamic grey matter (GM) in JME. Voxel-based morphometry (VBM) is a fully automated, unbiased, operator-independent MRI analysis technique that detects regionally specific differences in brain tissue composition on a voxel-wise comparison between groups of subjects. Using VBM, we examined structural differences in cortical and subcortical GM volume (GMV) between 25 JME patients (15 women, mean age=22.7+/-5.1 years) and age- and sex-matched 44 control subjects (27 women, mean age=23.1+/-4.3 years). We also performed a correlation analysis to delineate a possible relationship between the GMV increases or reductions and the increasing duration of epilepsy. Group comparison showed GMV increases in the superior mesiofrontal region bilaterally and GMV reductions in the thalamus bilaterally in JME patients (P<0.05, corrected for multiple comparisons using false discovery rate). Correlation analysis revealed that bilateral thalamic GMV had negative correlations with the duration of epilepsy (P<0.05, corrected for multiple comparisons after small volume corrections; P<0.05, Pearson correlation test). Our findings of GMV increases in the superior mesiofrontal regions and progressive thalamic atrophy could further support the pathophysiological concept of the functional abnormalities in thalamocortical circuit in JME.


Asunto(s)
Encéfalo/patología , Epilepsia Mioclónica Juvenil/patología , Adolescente , Adulto , Corteza Cerebral/patología , Interpretación Estadística de Datos , Femenino , Lóbulo Frontal/patología , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Tálamo/patología
17.
Hum Brain Mapp ; 28(11): 1128-35, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17525985

RESUMEN

Although studies of obsessive-compulsive disorder (OCD) over the last 20 years have suggested abnormalities in frontal-subcortical circuitry, evidences of structural abnormalities in those areas are still imperfect and contradictory. With recent advances in neuroimaging technology, it is now possible to study cortical thickness based on cortical surfaces, which offers a direct quantitative index of cortical mass. Using the constrained Laplacian-based automated segmentation with proximities (CLASP) algorithm, we measured cortical thickness of 55 patients with OCD (33 men and 22 women) and 52 age- and sex-matched healthy volunteers (32 men and 20 women). We found multiple regions of cortical thinning in OCD patients compared to the normal control group. Patients with OCD had thinner left inferior frontal, left middle frontal, left precentral, left superior temporal, left parahippocampal, left orbitofrontal, and left lingual cortices. Most thinned regions were located in the left ventral cortex system, providing a new perspective that this ventral cortical system may be involved in the pathophysiology of OCD.


Asunto(s)
Atrofia/patología , Corteza Cerebral/patología , Enfermedades Neurodegenerativas/patología , Trastorno Obsesivo Compulsivo/patología , Adulto , Atrofia/etiología , Atrofia/fisiopatología , Mapeo Encefálico , Corteza Cerebral/fisiopatología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Enfermedades Neurodegenerativas/fisiopatología , Trastorno Obsesivo Compulsivo/fisiopatología , Valor Predictivo de las Pruebas , Corteza Prefrontal/patología , Corteza Prefrontal/fisiopatología , Lóbulo Temporal/patología , Lóbulo Temporal/fisiopatología
18.
Neuroimage ; 31(2): 572-84, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16503170

RESUMEN

Cortical surface reconstruction is important for functional brain mapping and morphometric analysis of the brain cortex. Several methods have been developed for the faithful reconstruction of surface models which represent the true cortical surface in both geometry and topology. However, there has been no explicit comparison study among those methods because each method has its own procedures, file formats, coordinate systems, and use of the reconstructed surface. There has also been no explicit evaluation method except visual inspection to validate the whole-cortical surface models quantitatively. In this study, we presented a novel phantom-based validation method of the cortical surface reconstruction algorithm and quantitatively cross-validated the three most prominent cortical surface reconstruction algorithms which are used in Freesurfer, BrainVISA, and CLASP, respectively. The validation included geometrical accuracy and mesh characteristics such as Euler number, fractal dimension (FD), total surface area, and local density of points. CLASP showed the best geometric/topologic accuracy and mesh characteristics such as FD and total surface area compared to Freesurfer and BrainVISA. In the validation of local density of points, Freesurfer and BrainVISA showed more even distribution of points on the cortical surface compared to CLASP.


Asunto(s)
Corteza Cerebral/anatomía & histología , Imagen por Resonancia Magnética/métodos , Algoritmos , Lateralidad Funcional , Humanos , Procesamiento de Imagen Asistido por Computador , Fantasmas de Imagen , Piamadre/anatomía & histología , Reproducibilidad de los Resultados
19.
Neuroimage ; 27(1): 210-21, 2005 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-15896981

RESUMEN

Accurate reconstruction of the inner and outer cortical surfaces of the human cerebrum is a critical objective for a wide variety of neuroimaging analysis purposes, including visualization, morphometry, and brain mapping. The Anatomic Segmentation using Proximity (ASP) algorithm, previously developed by our group, provides a topology-preserving cortical surface deformation method that has been extensively used for the aforementioned purposes. However, constraints in the algorithm to ensure topology preservation occasionally produce incorrect thickness measurements due to a restriction in the range of allowable distances between the gray and white matter surfaces. This problem is particularly prominent in pediatric brain images with tightly folded gyri. This paper presents a novel method for improving the conventional ASP algorithm by making use of partial volume information through probabilistic classification in order to allow for topology preservation across a less restricted range of cortical thickness values. The new algorithm also corrects the classification of the insular cortex by masking out subcortical tissues. For 70 pediatric brains, validation experiments for the modified algorithm, Constrained Laplacian ASP (CLASP), were performed by three methods: (i) volume matching between surface-masked gray matter (GM) and conventional tissue-classified GM, (ii) surface matching between simulated and CLASP-extracted surfaces, and (iii) repeatability of the surface reconstruction among 16 MRI scans of the same subject. In the volume-based evaluation, the volume enclosed by the CLASP WM and GM surfaces matched the classified GM volume 13% more accurately than using conventional ASP. In the surface-based evaluation, using synthesized thick cortex, the average difference between simulated and extracted surfaces was 4.6 +/- 1.4 mm for conventional ASP and 0.5 +/- 0.4 mm for CLASP. In a repeatability study, CLASP produced a 30% lower RMS error for the GM surface and a 8% lower RMS error for the WM surface compared with ASP.


Asunto(s)
Mapeo Encefálico , Corteza Cerebral/fisiología , Procesamiento de Imagen Asistido por Computador/estadística & datos numéricos , Algoritmos , Líquido Cefalorraquídeo/fisiología , Lateralidad Funcional , Humanos , Modelos Estadísticos , Reproducibilidad de los Resultados
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