Malformações do desenvolvimento cortical: conceitos atuais e revisão de neuro-imagem avançada

Malformations of cortical development (MCD) result from disruptions in the complex process of the human brain cortex formation and are highly associated to severe epilepsy, neurodevelopmental delay and motor dysfunction. Nowadays, magnetic resonance imaging (MRI) is the cornerstone of the work-up of patients with epilepsy and modern advanced imaging techniques have improved not only our ability to detect and characterize cortical malformations, but also in identifying associated functional abnormalities that are far beyond the structural visualized lesions. Herein, we address the most currently used classifications of MCD and make a concise review of the embryological process of cortical development. Our main goal is to summarize recent advances and new trends in diagnostic imaging techniques concerning MCD. Thereafter, follows a brief discussion of specific disorders and their radiological features.As malformações do desenvolvimento cortical (MDC) resultam de distúrbios no complexo processo do desenvolvimento do córtex cerebral humano e estão comumente associadas a epilepsia severa e disfunções neuropsicomotoras. Atualmente, as imagens por ressonância magnética (RM) são a pedra angular no manejo de pacientes com epilepsia e modernas técnicas avançadas de imagem melhoraram não só a nossa capacidade de detectar e caracterizar as malformações corticais, mas também levaram ao reconhecimento de anomalias funcionais associadas que estão muito além das lesões estruturais visibilizadas. Abordaremos as classificações mais utilizadas de MDC e revisaremos a embriologia do desenvolvimento cortical. Nosso principal objetivo é destacar os avanços recentes e as novas tendências em técnicas de diagnóstico por imagens relacionadas às MDC. Em seguida, faremos uma breve discussão sobre alguns transtornos específicos e suas características radiológicas.FAPESPCNP

Dimensões da faringe em homens e mulheres saudáveis

INTRODUCTION: Epidemiological studies reveal a high male prevalence of obstructive sleep apnea syndrome. A possible explanation for this male predominance is the existence of anatomical differences in the upper airway between men and women. METHODS: The upper airways of 10 male and 10 female healthy volunteers were prospectively evaluated by magnetic resonance imaging. Anatomical pharyngeal and column cross-sectional linear measurements were made in sagittal T1 and axial T1 and T2 weighted fast spin-echo images. RESULTS: Men had significantly greater mean sagittal pharyngeal structural dimensions compared to women for all structures with the exception of the craniocaudal length of the soft palate and the thickness of the submentonian fat. In contrast, cross-sectional linear dimensions were similar in men and women with the exception of the laterolateral tongue length, which was greater in men. All mean linear measurements of the pharyngeal air column were similar in men and women at all studied levels. CONCLUSIONS: Men and women present pharyngeal air columns with similar dimensions, but in women this column is surrounded by smaller structures, which might imply a smaller effort to keep its patency. Our data suggest the existence of an anatomical protective factor in women against the upper airway collapse.INTRODUÇÃO: Estudos epidemiológicos demonstram alta prevalência da síndrome da apnéia obstrutiva do sono no sexo masculino. Uma explicação plausível para esta predominância masculina é a existência de diferenças anatômicas nas vias aéreas superiores entre homens e mulheres. MÉTODOS: As vias aéreas superiores de 10 homens e 10 mulheres, voluntários saudáveis, foram avaliados prospectivamente através do exame de ressonância magnética. Foram realizadas medidas lineares das vias aéreas superiores e das estruturas da faringe através de imagens sagitais pesadas em T1 e imagens axiais pesadas em T1 e T2 com a técnica de fast spin-echo. RESULTADOS: Os homens mostraram dimensões significativamente maiores das estruturas da faringe em relação às mulheres em todas as medidas realizadas nas imagens sagitais, com exceção do diâmetro crânio-caudal do palato mole e da espessura da gordura submentoniana. Em contraste, as imagens axiais mostraram medidas similares entre os sexos, exceto o diâmetro látero-lateral da língua que foi maior nos homens. Todas as medidas da coluna aérea das vias aéreas superiores foram semelhantes nos dois sexos. CONCLUSÕES: Embora homens e mulheres apresentem vias aéreas superiores com dimensões similares, nas mulheres as estruturas anatômicas ao seu redor são menores, sugerindo um menor esforço para manter as vias aéreas superiores patentes no sexo feminino. Nossos resultados sugerem a existência de um fator de proteção anatômico contra o colapso das vias aéreas superiores nas mulheres

Segmented corpus callosum diffusivity correlates with the Expanded Disability Status Scale score in the early stages of relapsing-remitting multiple sclerosis

OBJECTIVE: The aim of this study was to characterize the microscopic damage to the corpus callosum in relapsing-remitting multiple sclerosis (RRMS) with diffusion tensor imaging and to investigate the correlation of this damage with disability. The diffusion tensor imaging parameters of fractional anisotropy and mean diffusivity provide information about the integrity of cell membranes, offering two more specific indices, namely the axial and radial diffusivities, which are useful for discriminating axon loss from demyelination. METHOD: Brain magnetic resonance imaging exams of 30 relapsing-remitting multiple sclerosis patients and 30 age- and sex-matched healthy controls were acquired in a 3T scanner. The axial diffusivities, radial diffusivities, fractional anisotropy, and mean diffusivity of five segments of the corpus callosum, correlated to the Expanded Disability Status Scale score, were obtained. RESULTS: All corpus callosum segments showed increased radial diffusivities and mean diffusivity, as well as decreased fractional anisotropy, in the relapsing-remitting multiple sclerosis group. The axial diffusivity was increased in the posterior midbody and splenium. The Expanded Disability Status Scale scores correlated more strongly with axial diffusivities and mean diffusivity, with an isolated correlation with radial diffusivities in the posterior midbody of the corpus callosum. There was no significant correlation with lesion loads. CONCLUSION: Neurological dysfunction in relapsing-remitting multiple sclerosis can be influenced by commissural disconnection, and the diffusion indices of diffusion tensor imaging are potential biomarkers of disability that can be assessed during follow-up

Magnetic resonance imaging findings of intracranial gossypiboma: a case report and literature review

Vários trabalhos têm descrito as características de gossipibomas por meio de radiografias convencionais e tomografia computadorizada, porém, seus achados na ressonância magnética são menos conhecidos. O objetivo deste estudo foi descrever as características de imagem de gossipibomas, ilustrando um caso de uma paciente com quadro clínico de febre e confusão mental com antecedente de cirurgia encefálica.Many reports in the literature have described findings of gossypibomas at conventional radiography and computed tomography. However, magnetic resonance imaging findings are still to be completely known. The purpose of the present study was to describe imaging findings of gossypibomas in a patient with previous history of brain surgery, presenting fever and mental confusion