RESUMO
ABSTRACT This paper presents an improved classification system for brain tumours using wavelet transform and neural network. The anisotropic diffusion filter was used for image denoising, and the performance of the oriented rician noise reducing anisotropic diffusion (ORNRAD) filter was validated. The segmentation of the denoised image was carried out by fuzzy c-means clustering. The features were extracted using symlet and coiflet wavelet transforms, and the Levenberg-Marquardt algorithm based neural network was used to classify the magnetic resonance (MR) images. This classification technique of MR images was tested and analysed with existing methods, and its performance was found to be satisfactory with a classification accuracy of 93.24%. The developed system could assist physicians in classifying MR images for better decision-making.
RESUMEN Este artículo presenta un sistema de clasificación mejorado para los tumores de cerebro usando la transformada de ondeletas (transformada wavelet) y la red neuronal. El filtro de difusión anisotrópica fue utilizado para la eliminación del ruido de la imagen, y se validó el funcionamiento del filtro de difusión anisotrópica orientado a reducir el ruido riciano (ORNRAD, siglas en inglés). La segmentación de la imagen 'desruidizada ' (denoised) fue realizada mediante el agrupamiento difuso c-means fuzzy. Las características fueron extraídas usando las transformadas de ondeletas symlet y coiflet, y la red neuronal basada en el algoritmo de Levenberg-Marquardt fue utilizada para clasificar las imágenes de resonancia magnética (RM) imágenes. Esta técnica de clasificación de imágenes de RM fue probada y analizada con métodos existentes, y se halló que su rendimiento era satisfactorio con una precisión de clasificación de 93.24%. El sistema desarrollado podría ayudar a los médicos a clasificar imágenes de RM para una mejor toma de decisiones.
Assuntos
Humanos , Neoplasias Encefálicas/classificação , Neoplasias Encefálicas/diagnóstico por imagem , Análise de Ondaletas , Rede Nervosa/diagnóstico por imagem , Imageamento por Ressonância MagnéticaRESUMO
Introducción: Un paciente con tumor epidermoides intracraneal extradural con presentación sincrónica con absceso cerebral, sin antecedentes de trauma craneal penetrante, no ha sido reportado con anterioridad en la revisión del tema realizada por los autores. Se presenta un caso con estas características y se exponen consideraciones sobre el diagnóstico y el tratamiento. Caso clínico: Paciente femenina, de 48 años de edad, con antecedentes de cefalea crónica y tumor craneal palpable en región frontal izquierda. Los estudios humorales fueron normales. La RNM craneal mostró dos imágenes en anillo yuxtapuestas, extra e intraaxial de forma respectiva. En la cirugía se encontró tumor perlado extradural sin evidencia a la inspección de tumor intradural, se comprobó en el examen histopatológico tumor epidermoides. En los controles imagenológicos posoperatorios se descubrió la persistencia de la lesión intraaxial, en anillo, frontal izquierda. Una segunda cirugía evidenció un absceso cerebral de ubicación subcortical y se efectuó la resección radical. La evolución fue favorable, sin secuelas después de cuatro meses de seguimiento. Conclusiones: Se reportó un caso infrecuente, donde se presentó de forma sincrónica un tumor epidermoides extradural frontal izquierdo y absceso cerebral frontal ipsilateral, sin relación de continuidad ni comunicación fistulosa demostrada en las neuroimágenes ni en la exploración quirúrgica.
Introduction: A patient with intracranial extradural epidermoid tumor with synchronous presentation with brain abscess and no history of penetrating head trauma, has not been previously reported in the revision of the subject made by the authors. A case with these characteristics is presented and also considerations about diagnosis and treatment. Case report: A 48-yearold female patient, with a history of chronic headache and cranial palpable tumor in left frontal region. Humoral studies were normal. Cranial MRI showed two juxtaposed, extra and intraaxial ring images. At surgery an extradural pearly tumor without evidence of intradural tumor on inspection was found, biopsy showed an epidermoid tumor. Persistence of intraaxial ring lesion in left frontal lobe was showed in postoperative imaging controls. A second surgery discovered a subcortical brain abscess and radical resection was done. Patient outcome has been without sequelae after four months of follow-up. Conclusions: An uncommon case where reported with extradural left frontal epidermoid tumor and ipsilateral frontal brain abscess synchronously presented, neither continuity nor fistulous communication were demonstrated on neuroimaging or surgical exploration.
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Humanos , Feminino , Pessoa de Meia-Idade , Abscesso Encefálico , Carcinoma de Células Escamosas , Lobo Frontal , Neoplasias Encefálicas/cirurgia , Neoplasias Encefálicas/diagnóstico , Cisto Epidérmico/cirurgia , Cisto Epidérmico/diagnóstico , Craniotomia/métodos , Espectroscopia de Ressonância Magnética/métodos , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodosRESUMO
Este trabalho descreve o desenvolvimento de um método que classifica de forma semi-automática a degeneração de discos intervertebrais lombares em imagens de ressonância magnética ponderadas em T2. O conjunto de imagens consiste de 210 discos extraídos de exames de 94 indivíduos (20 a 80 anos). A classificação é feita por uma rede neural do tipo perceptron multicamada com 6 entradas, 15 neurônios na camada intermediária e 1 saída. Os resultados obtidos mostraram uma taxa média de acerto de 81,42%, com erro padrão de 9,11%.
This article describes the development of a method that classifies semi-automatic degeneration of lumbar intervertebral discs in magnetic resonance T2-weighted images. The dataset consists of images of 210 discs obtained from94 individuals (20 to 80 year old). An artificial neural network of the multilayer perceptron with 6 inputs, 15 neuronsin the hidden layer and 1 output, was used to check the efficiency of this study. Obtained an average rate of sucess of81.42%, with a standard error of 9.11%.
Assuntos
Humanos , Imageamento por Ressonância Magnética , Degeneração do Disco Intervertebral/classificação , Pesos e Medidas , Congressos como AssuntoRESUMO
Los Criterios Diagnósticos para la Investigación de los Trastornos Temporomandibulares (CDI/TTM) ofrecen un sistema estandarizado para evaluar la Disfunción Temporomandibular (DTM). Sin embargo, la validez del diagnóstico clínico obtenido con estos criterios al compararlo con el diagnóstico obtenido de las imágenes de Resonancia Magnética (RM) es controversial. El objetivo fue determinar la concordancia que existe entre la evaluación clínica realizada con los CDI/TTM e imágenes de RM de la articulación temporomandibular (ATM), de pacientes atendidos en la Clínica Integral del Adulto, de la Escuela de Odontología de la Universidad del Valle, en Cali, Colombia. Se evaluó clínicamente a 36 individuos, con edades comprendidas entre 18 y 60 años, utilizando los CDI/TTM y se les realizaron exámenes de RM. Las variables estudiadas fueron sexo, edad, signos y síntomas de la ATM, Posición Normal del Disco (PND), Desplazamiento Discal con Recaptura (DDCR) y Desplazamiento Discal Sin Recaptura (DDSR). Los datos obtenidos fueron sometidos a pruebas estadísticas para determinar el índice Kappa y características operativas de la prueba clínica. El Índice Kappa fue 0,53, con una concordancia entre las evaluaciones clínicas e imagenológicas moderada. De la población estudiada, 91,6% fue del sexo femenino, con 31 años como promedio de edad. El signo hallado con mayor frecuencia fue el ruido articular (77%) y el síntoma más frecuente fue el dolor facial (69%). La sensibilidad de los CDI/TTM para determinar la PND fue 0,52 y la especificidad 0,87; la sensibilidad para el DDCR fue 0,8780 y la especificidad 0,709; la sensibilidad para el DDSR fue 0,5714 y la especificidad 0,948. La DTM se presentó con mayor frecuencia en las mujeres, con edad promedio de 31 años. Los CDI/TTM pueden considerarse confiables, especialmente para el DDCR; sin embargo, tratamientos invasivos, permanentes o quirúrgicos, requerirían confirmación con un diagnóstico imagenológico para evitar falsos positivos.
The Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) offer a standardized system to clinically evaluate the most common subtypes of Temporomandibular Disorders (TMD). However, the validity of the clinical diagnose obtained with these criteria when compared with the diagnose obtained from the images of Magnetic Resonance (MR) is controversial. The objective of this study was to determine the concordance existing between the clinical evaluation obtained from the RDC/TMD and that obtained from MR images of the temporomandibular joint (TMJ) of patients attending the Clínica Integral del Adulto Clínica de ATM, of the Escuela de Odontología of the Universidad del Valle, Cali, Colombia. A population of 36 patients of both sexes, with ages between 18 and 60 years, were clinically evaluated with the RDC/TMD and MR. The variables considered were sex, age, signs and symptoms of the TMJ, Normal Disc Position (NDP), Disc Displacement with Reduction (DD-R) and Disc Displacement without Reduction (DD-NR). The data obtained were submitted to statistical tests to determine the Kappa Index and operative characteristics of the clinical evaluation. The Kappa Index obtained was 0.53, which shows that the concordance between the clinical and the imagenological evaluations is moderate. Of the total population studied, 91.6% were females, with 31 years as average age. The most frequent sign found was the joint sound (77%) and the most frequent symptom was facial pain (69%). The sensitivity of the RDC/TMD to determine NDP was 0.52 and the specificity 0.87; the sensitivity for the DD-R was 0.8780 and the specificity 0.709; the sensitivity for the DD-NR was 0.5714 and the specificity 0.948. The TMD were found most frequent in women, with average age of 31 years. The RDC/TMD can be considered reliable, especially for the DD-R; however, invasive, permanent or surgical treatments would require confirmation with imagenological diagnoses to avoid false positives.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Transtornos da Articulação Temporomandibular/diagnóstico , Articulação Temporomandibular/diagnóstico por imagem , Imageamento por Ressonância Magnética , Síndrome da Disfunção da Articulação Temporomandibular/diagnóstico , Valor Preditivo dos Testes , Estudos Prospectivos , Curva ROC , Sensibilidade e Especificidade , Disco da Articulação TemporomandibularRESUMO
INTRODUÇÃO: Imagens por tensores de difusão (diffusion tensor imaging - DTI) do cérebro são parte fundamental de exames de ressonância magnética (RM) na rotina clínica. Entretanto, não há informação científica suficiente para inferir a base histológica de parâmetros de imagens de DTI. Um dos achados frequentes nos exames de RM são as áreas de alteração de sinal na substância branca (AASSB). Neste estudo, analisamos imagens de RM post-mortem, em particular as AASSB, e seus correlatos histológicos e imuno-histoquímicos. OBJETIVOS: Descrever os parâmetros quantitativos de imagens de DTI imagens obtidas in cranio post-mortem, comparar com parâmetros de relaxometria e transferência de magnetização e avaliar seus correlatos histológicos nas AASSB e AHAN, utilizando técnicas de correspondência espacial ponto-a-ponto. MÉTODOS: Analisamos áreas distribuídas na substância branca de encéfalos de quatro sujeitos submetidos ao exame de RM post-mortem, aproximadamente 12,87 horas (±2,59). A RM foi realizada em sistema com campo de 3,0 T, sendo utilizadas imagens FLAIR; T2 multi-eco, DTI, Densidade de Prótons para cálculo da taxa de transferência de magnetização (magnetization transfer ratio - MTR). Foram delimitadas regiões de interesse (ROI) em 20 áreas contendo AASSB e 20 áreas homólogas aparentemente normais (AHAN). Para cada área, foram obtidos valores de anisotropia fracional (FA), coeficiente de difusão aparente (ADC), MTR e tempo T2. Os encéfalos foram seccionados em fatias de 0,4mm e fotografados em alta resolução. Estas imagens foram co-registradas tridimensionalmente com as imagens de RM, utilizando técnica semi-automatizada para correlação ponto-a-ponto. Os fragmentos analisados foram corados por hematoxilina-eosina (HE), Kluverx Barrera (KB), galocianina (GALL), anti-neurofilamento (anti-NF), antiproteína básica de mielina (anti-MBP) e anti-proteína ácida fibrilar glial (anti- GFAP). RESULTADOS: Os valores de FA foram 0,40 ±0,12 nas...
BACKGROUND: Diffusion tensor imaging (DTI) is part of magnetic resonance imaging (MRI) acquisition methods available in clinical exams. However, there are not enough scientific basis to infer the histological substract of DTI parameters. White matter hyperintensities (WMH) are frequent findings in clinical MRI routine. In the last years, scientific evidences show that these injuries are not just age-related benign changes, but they could be associated to pathological processes. In this study we analyzed post-mortem MRI DTI data, specifically investigating WMH, their histological and immunohistochemical correlates. OBJECTIVES : At present study, we aimed to analyze quantifiable DTI parameters - Fractional Anisotropy (FA) and Apparent Diffusion Coefficient (ADC) - relaxometry (RT2) and magnetization transfer ratio (MTR) in WMH compared and normal appearing white matter (NAWM) from images obtained postmortem and in situ, and assess their histological substracts at WMH and NAWM using a point-topoint correlation platform. METHODS : We analyzed 20 regions of interest (ROI) encompassing WMH and NAWM selected from four subjects using in situ post-mortem MRI data acquired in 3.0T MR system. The subjects were scanned with a post-mortem interval of approximately 12h54m (±2h36m). The MRI analysis included 3D T1, FLAIR; multi-echo T2, DTI, and proton density to calculate the rate of magnetization transfer (magnetization transfer ratio - MTR). In each ROI we obtained measures of FA, ADC, RT2 and MTR. Brain specimens were posteriorly fixed in celloidin, sectioned into 0.4mm slices and photographed in high resolution. These images were co-registered with three-dimensional MR images using semi-automated technique for correlation using a point-to-point method established in our group. WMH and NAWM ROIs from MRI were submitted to quantitative histological analysis based on optical density color-deconvolution technique. Histological section were stained in...
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Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Envelhecimento , Anisotropia , Cérebro , Imagem de Tensor de Difusão , Imuno-Histoquímica , Espectroscopia de Ressonância MagnéticaRESUMO
Objetivo: Estudiar el comportamiento del uso de razones entre metabolitos y de la comparación de un volumen de interés con uno contralateral para determinar cuál de estas 2 técnicas es la más apropiada para obtener una relación del comportamiento metabólico de un espectro de resonancia magnética. Métodos: Fueron reclutados 10 voluntarios sanos, en los que fueron analizados el lóbulo parietal, el lóbulo temporal y los ganglios basales. Resultados: La cuantificación directa del espectro mostró un mayor coeficiente de variación dentro de los análisis realizados, lo cual justifica usar técnicas con referentes endógenos. El estudio de un volumen contralateral mostró ser una técnica con dispersión e índice de lateralidad altos. El uso de la creatina (Cr) como metabolito de control presentó un coeficiente de variación menor que la primera técnica evaluada. Los resultados hallados (ganglios basales: n-acetil-aspartato/Cr: 3 ± 6; colina/Cr: 2 ± 4. Lóbulo temporal: N-acetil-aspartato/Cr: 5 ± 5; colina/Cr: 8 ± 12. Lóbulo parietal: N-acetil-aspartato/Cr: 2,0 ± 0,6; colina/Cr: 0,9 ± 0,5) muestran valores similares a los encontrados en la literatura, con variaciones regionales considerables. Conclusiones: La técnica de cuantificación de la razón de los metabolitos con la Cr es la más adecuada para usar en el Instituto Nacional de Cancerología, por tener una dispersión menor y por arrojar valores cercanos a los reportados en la literatura en las diferentes regiones anatómicas estudiadas.
Objective: To study the performance in the use of metabolite ratios and the comparison of a contralateral volume of interest in order to determine which of these two techniques is most suitable for obtaining a ratio of the metabolite behaviour of a magnetic resonance spectrum. Methods: The parietal lobe, the temporal lobe, and basal ganglions were analysed in the 10 healthy volunteers included in the study. Results: The direct quantification of the spectra showed a wide coefficient of variation within the analyses performed, which justified using techniques with endogenous references. The study of a contralateral volume showed to be a technique with a high dispersion and laterality index. The use of creatinine (Cr) as a control metabolite had a lower coefficient of variation than the first technique evaluated. The results obtained (basal ganglions: N-acetyl-aspartate/Cr: 3 ± 6; choline/Cr: 2 ± 4. Temporal lobe: N-acetyl-aspartate/Cr: 5 ± 5; choline/Cr: 8 ± 12. Parietal Lobe: N-acetyl-aspartate/Cr: 2.0 ± 0.6; choline/Cr: 0.9 ± 0.5) showed similar values to those obtained in the literature, with considerable anatomical region variations. Conclusions: The technique that measures the ratio of the metabolites with Cr is the most suitable for use in the Instituto Nacional de Cancerología (National Oncology Institute), due to having a lower dispersion and producing results near those repo rted in the literature in the different anatomical regions studied.
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Humanos , Espectroscopia de Ressonância Magnética , Métodos , Métodos , Imageamento por Ressonância Magnética MultiparamétricaRESUMO
Purpose: Epidermoid and dermoid cysts are extremely rare developmental cysts of a benign nature, which may occur anywhere in the body, although about 7% are found in the head and neck. This article reports a clinical case of a patient who had an epidermoid cyst and its magnetic resonance imaging (MRI) features. Case report: This case discusses an epidermoid cyst in a 36-year-old woman complaining about speech difficulty. Clinical examination revealed an extensive swelling on the floor of the mouth. MRI findings showed a cystic homogenous lesion located underneath the mylohyoid muscle which was removed by surgery. Histological examination of the mass confirmed the diagnosis of an epidermoid cyst. Conclusion: We concluded that MRI was considered useful for a more accurate diagnosis prior to treatment.
Proposta: Cistos epidermóide e dermóide são cistos de desenvolvimento extremamente raros, de natureza benigna, que podem ocorrer em qualquer região do corpo e somente 7% são encontrados na região de cabeça e pescoço. Este artigo apresenta o caso clínico de uma paciente que possuía um cisto epidermóide juntamente com as características das imagens por ressonância magnética. Descrição do caso: Paciente do gênero feminino, 36 anos, apresentou-se com queixa de dificuldade de fonação e deglutição. O exame clínico intrabucal revelou uma extensa tumefação em soalho bucal. As imagens por ressonância magnética indicaram uma lesão de natureza cística, homogênea, de conteúdo sólido e localizada abaixo do músculo milohiódeo. A lesão foi enucleada e encaminhada para exame anatomopatológico, cujo diagnóstico foi compatível com cisto epidermóide. Conclusão: A imagem por ressonância magnética foi essencial para determinar as características da lesão de acordo com a sua localização anatômica.