[Spine neuroimaging: computed tomography diagnostic signs]. / Avaliação imagiológica da coluna vertebral: sinais diagnósticos em tomografia computorizada.

INTRODUCTION: Computed tomography (CT) scans of the spine are among the most frequently performed neuroradiologic exams, studying several pathologies namely degenerative diseases. Specific signs in spine imaging initially described in conventional radiology can be applied to CT scans. The main goal of this work was their identification and characterization. METHODS: A review of the main imagiological signs in CT scans of the spine was performed. RESULTS AND DISCUSSION: The authors described those imagiological signs and correlated them with their associated pathologies. CONCLUSION: The knowledge of these signs is extremely important to neuroradiologists as they often constitute important diagnostic clues in several pathologies.

[Diffusion-weighted MR imaging characterization of progressive multifocal leucoencefalopathy (PML) lesions]. / Caracterização das lesões de leucoencefalopatia multifocal progressiva por imagem de ressonância magnética ponderada em difusão.

INTRODUCTION: Progressive multifocal leucoencefalopathy (PML) is a subacute demielinating disease of the Central Nervous System caused by the neurotropic virus John Cunningham (JC), common in immunodeficient patients, namely in HIV infection. PML encephalic lesions have a progressive nature that needs characterization and progressive study, especially for evaluating the therapeutic response. MATERIAL AND METHODS: The authors reviewed diffusion-weight MR imaging of PML lesions in four patients, characterizing the different lesional areas in DWI and ADC maps, and correlating these data with previous published studies, namely regarding histological correlation and lesion time course. RESULTS: The four cases studied showed heterogeneity in DWI and ADC maps, with restriction in water diffusion in the periphery of each lesion. DISCUSSION/CONCLUSION: Diffusion-weighted MR images allows characterization of PML lesions, highlighting their heterogeneity and asynchrony. These data allow important knowledge on lesions temporal evolution and treatment response.

[Double aortic arch: incidental cerebral angiography finding in an adult patient with headache--embrionary cardiovascular morphogenic pattern review]. / Duplo arco aórtico: achado acidental em angiografia cerebral de um paciente adulto com cefaleias--revisão do padrão de morfogénese embrionária cardiovascular a propósito de um caso clínico.

INTRODUCTION: Cerebral angiography is a technique used to detect cerebral vessel anomalies. It is critical that a neuroradiologist is familiar with the normal anatomic development and its anomalies as, during an angiography, they may influence the way the procedure is done. METHODS: Regarding an incidental finding of a double aortic arch during a cerebral angiography in an adult patient, the authors proceeded to a bibliographic review of the normal embriogenic cardiovascular morphogenesis patterns and its anomalies. DISCUSSION: The existence of a double aortic arch constitutes an embrionary pattern typical at six weeks of gestation that results from the process of progression/regression of the six pairs of pharyngeal arches; usually the double aortic arch regresses during the seventh week of gestation. When the fourth right pharyngeal arch and the right dorsal aorta do not regress, this double aortic pattern persists after birth. There are several symptoms related to this anomaly but in some rare cases, like the one presented, they might be absent and are only identified accidentally. CONCLUSION: Studying the pattern of cardiovascular morphogenesis and its anomalies helps the neuroradiologist performing a cerebral angiogram.