Preliminary experience with 3 tesla magnetic resonance for evaluation of the fetal brain

Orientadores: José Vassallo, Luis Otávio Zanatta SarianTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: Introdução: A ressonância magnética (RM) é um excelente método diagnóstico complementar à ultrassonografia (US) pré-natal para elucidar anomalias morfológicas fetais. A alta sensibilidade diagnóstica da RM fornece informações importantes para o manejo da gestação e do parto. Após sua introdução no diagnóstico pré-natal em 1983, a RM fetal foi realizada inicialmente em aparelhos de potência de campo inferior à 1 Tesla (1T), e devido à evolução técnica, posteriormente em aparelhos de campo magnético de 1,5 T, em acordo com as recomendações do National Radiological Protection Board, International Non-Ionizing Radiation Committee of the International Radiation Protection Association (International Commission on Non-Ionizing Radiation Protection ¿ ICNIRP), e dos manuais de segurança em ressonância magnética (MRI safety). Os aparelhos de ressonância magnética com campo magnético de 3T fornecem elevada resolução espacial e aquisições rápidas, aumentando desta maneira o espectro de aplicações clínicas. Objetivo: Relatar nossa experiência preliminar com ressonância magnética do cérebro fetal com um aparelho de potência de campo magnético de 3T considerando os seguintes aspectos: tempo de aquisição das imagens, artefatos de imagem provocados pelo alto campo magnético e determinação do diagnóstico. Metodologia: Em 59 mulheres gestantes foram realizados 60 exames de RM cerebral fetal em aparelho de campo magnético de 3T durante o terceiro trimestre da gestação. As indicações para a RM eram: US com suspeita de anomalia do sistema nervoso central (SNC) ou antecedentes de gestação com malformação congênita do SNC. Nenhuma sedação fetal ou materna foi usada. O protocolo de RM consistiu em imagens T2 turbo-spin-eco (TSE) do cérebro fetal nos planos axial, sagital, coronal. Nenhuma imagem ponderada em T1 foi realizada. As imagens foram analisadas em conjunto por dois neurorradiologistas pediátricos, os quais avaliaram: tempo de aquisição, presença de artefatos, os diagnósticos encontrados. Resultados: Todos os exames foram realizados sem intercorrências clínicas maternas e/ou obstétricas. As imagens tinham elevado tempo de aquisição (75 segundos para cada plano do espaço). A taxa de absorção específica (SAR) não foi excedida em nenhum feto. A RM cerebral foi normal em 22 casos. O espectro de diagnósticos incluiu: ventriculomegalia isolada, malformação da fossa posterior, malformação do corpo caloso, anomalias de giração, craniossinostose, esclerose tuberosa, microcefalia, hidrocefalia externa, cisto de aracnóide, lesões cerebrais e persistência de vítreo primitivo hiperplásico. Foram realizadas 12 autópsias que evidenciaram concordância total com os achados de RM em 10 casos. Em 2 casos, houve mínimas discordâncias. Conclusão: Em nossa série, a RM cerebral fetal em aparelho de 3T requisitou elevado tempo de aquisição, não apresentou artefatos que impossibilitassem o diagnóstico e foi capaz de fornecer os diagnósticos (normais e patológicosAbstract: Introduction: Magnetic resonance imaging (MRI) is an excellent diagnostic method complementary to prenatal ultrasonography (US) to elucidate fetal morphological abnormalities. The high diagnostic sensitivity of MRI provides important information for the management of pregnancy and delivery. After its introduction in the prenatal diagnosis in 1983, fetal MRI was initially performed on magnetic field devices equal to or less than 1 Tesla (1T), and due to technical developments, then on 1.5 Tesla magnetic field devices, according to the recommendations of the National Radiological Protection Board, International Non-Ionizing Radiation Committee of the International Radiation Protection Association (International Commission on Non-Ionizing Radiation Protection ¿ ICNIRP) and magnetic resonance safety manuals. 3T MRI devices provide high spatial resolution and rapid acquisition, thus increasing the spectrum of clinical applications. Objective: To report our preliminary experience with MRI of the fetal brain with a 3T magnetic field power device considering the following aspects: time of acquisition of the images, artifacts, the diagnoses found. Methodology: Fifty-nine pregnant women had fetal MRI performed during the third trimester of pregnancy due to clinical or sonography concern of a central nervous system (CNS) anomaly. No fetal or maternal sedation was used. The MRI protocol consisted of T2 turbo-spin-echo images (TSE) in three planes of space. No T1 weighted (W) images were performed. All images were analyzed together by two pediatric neuroradiologists, who evaluated: artifacts, time of acquisition of the images, and the diagnoses found. Results: All the exams were performed without maternal and / or obstetric clinical complications. The images required longer time of acquisition (75 seconds for each plane in the space). The specific absorption rate (SAR) was not exceeded in any fetus. Cerebral fetal MRI was normal in 22 cases. The spectrum of diagnostics included: isolated ventriculomegaly, posterior fossa malformation, corpus callosum malformation, gyration anomalies, craniosynostosis, tuberous sclerosis, microcephaly, external hydrocephaly, midline arachnoid cyst, cerebral lesions, and persistent hyperplastic primitive vitreous. Twelve autopsies were performed that showed total concordance with MRI findings in 10 cases. In 2 cases, there were minimal disagreements. Conclusion: In our series, fetal brain MRI in a 3T device required a high acquisition time, did not present artifacts that made the diagnosis impossible and was able to provide the diagnoses (normal and pathological)DoutoradoClinica MedicaDoutor em Ciência

Pituitary Macroadenoma Presenting As A Nasal Tumor: Case Report.

Pituitary macroadenomas are rare intracranial tumors. In a few cases, they may present aggressive behavior and invade the sphenoid sinus and nasal cavity, causing unusual symptoms. In this paper, we report an atypical case of pituitary adenoma presenting as a nasal mass. The patient was a 44-year-old woman who had had amenorrhea and galactorrhea for ten months, with associated nasal obstruction, macroglossia and acromegaly. Both growth hormone and prolactin levels were increased. Magnetic resonance imaging showed a large mass originating from the lower surface of the pituitary gland, associated with sella turcica erosion and tumor extension through the sphenoid sinus and nasal cavity. Histopathological analysis demonstrated a chromophobe pituitary adenoma with densely packed rounded epithelial cells, with some atypias and rare mitotic figures. There was no evidence of metastases. Macroadenoma invading the nasal cavity is a rare condition and few similar cases have been reported in the literature. This study contributes towards showing that tumor extension to the sphenoid sinus and nasopharynx needs to be considered and investigated in order to make an early diagnosis when atypical symptoms like nasal obstruction are present.132377-8

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XIXI

Central Nervous System Involvement In Sarcoidosis.

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Neuroparacoccidioidomycosis (npcm): Magnetic Resonance Imaging (mri) Findings.

To describe the magnetic resonance imaging (MRI) patterns of the central nervous system (CNS) involvement by neuroparacoccidioidomycosis (NPCM). Between January 1999 and March 2011, a review of MRI data analysis from 8 cases of NPCM was performed. The following MRI characteristics were examined by an experienced neuroradiologist: topography of lesions, aspects on T1- and T2-weighted images (WI), contrast enhancement, diffusion and spectroscopy. All patients had evidence of paracoccidioidomycosis infection outside the nervous system. Regarding CNS involvement, five patients had only supratentorial lesions; three had infra- and supratentorial ones. Meningeal extension occurred in three patients. The lesions were predominantly hyperintense on T1WI. At T2WI, a hypointense component was present in five cases as well as a perilesional abnormal white matter. A ring-enhancement pattern was seen in five cases. Spectroscopy was performed in three patients and showed an increased lipid peak in all of them. In one case, there was also an increased choline peak. NPCM is rare, and MRI may help its differentiation from other inflammatory lesions. However, the presence of active infection outside CNS and some imaging characteristics should point to this diagnosis.175181-

Pituitary macroadenoma presenting as a nasal tumor: case report

CONTEXT: Pituitary macroadenomas are rare intracranial tumors. In a few cases, they may present aggressive behavior and invade the sphenoid sinus and nasal cavity, causing unusual symptoms. In this paper, we report an atypical case of pituitary adenoma presenting as a nasal mass.CASE REPORT: The patient was a 44-year-old woman who had had amenorrhea and galactorrhea for ten months, with associated nasal obstruction, macroglossia and acromegaly. Both growth hormone and prolactin levels were increased. Magnetic resonance imaging showed a large mass originating from the lower surface of the pituitary gland, associated with sella turcica erosion and tumor extension through the sphenoid sinus and nasal cavity. Histopathological analysis demonstrated a chromophobe pituitary adenoma with densely packed rounded epithelial cells, with some atypias and rare mitotic figures. There was no evidence of metastases.CONCLUSION: Macroadenoma invading the nasal cavity is a rare condition and few similar cases have been reported in the literature. This study contributes towards showing that tumor extension to the sphenoid sinus and nasopharynx needs to be considered and investigated in order to make an early diagnosis when atypical symptoms like nasal obstruction are present