Resumo Objetivo: Avaliar aspectos práticos do uso de agentes de contraste à base de gadolínio (gadolinium-based contrast agents - GBCAs) por médicos especialistas em radiologia. Materiais e Métodos: Dez radiologistas de diferentes regiões do Brasil foram convidados a participar de um painel Delphi com perguntas sobre o uso de GBCAs lineares e macrocíclicos (1,0 e 0,5 M), em termos de dosagem, volume injetado e preocupações relacionadas à segurança. Resultados: A taxa de resposta foi de 100% para todas as perguntas. GBCAs são seguros em relação a reações adversas agudas, e os casos de fibrose nefrogênica sistêmica são raros. O depósito de gadolínio no cérebro e em outros tecidos é uma preocupação de todo o painel. Agentes macrocíclicos são preferíveis aos lineares. Um volume menor que 0,1 mL/kg injetado de contraste macrocíclico 1,0 M poderia oferecer imagem com boa qualidade e benefício adicional em longo prazo, entretanto, não há evidências publicadas que apóiem tal recomendação. A maioria prefere não administrar GBCA em gestantes. Conclusão: É importante considerar as características de deposição e minimizar potenciais riscos ao se escolher um GBCA. Ações de educação médica são necessárias para a conscientização dos potenciais riscos da presença de gadolínio em longo prazo e evitar a sobre-exposição ao agente de contraste.

Abstract Objective: To assess the practical aspects of the use of various gadolinium-based contrast agents (GBCAs) by radiologists. Materials and Methods: Ten experienced radiologists from different regions of Brazil participated in a Delphi panel querying their use of various GBCAs, including linear and macrocyclic classes (1.0 and 0.5 M), in terms of the choice of agent, volume and dosage of the agents, and associated safety concerns. Results: The response rate was 100% for all questions. GBCAs are safe in terms of acute adverse reactions, and nephrogenic systemic fibrosis is rare. The deposition of gadolinium in the brain and other tissues is a concern among the experts. Macrocyclic agents are preferable to linear agents; an injection volume below 0.1 mL/kg of a 1.0 M agent could result in good-quality images with additional long-term safety, but there is no published evidence to support this recommendation. The majority of experts preferred not to administer GBCAs to pregnant patients. Conclusion: When choosing a GBCA, it is important to consider the characteristics of the gadolinium deposition in patient tissues and minimize potential risks. Furthermore, medical education programs are needed to increase the awareness of the potential risks of gadolinium deposition and thus avoid instances of overexposure to the contrast agent.

RESUMO No que se refere à necessidade de um método preciso e padronizado para a detecção de atividade inflamatória em esclerose múltipla (EM), diferentes aquisições de RM devem ser comparadas com objetivo de escolher a sequência mais sensível para a rotina clínica. Objetivo Comparar a sensibilidade das sequências ponderadas em T1 após a administração endovenosa de uma única dose de gadolínio, com e sem a adição da transferência de magnetização, para detectar a impregnação das lesões desmielinizantes focais agudas. Métodos Uma amostra de pacientes com EM-RR foi prospectivamente avaliada separadamente por dois neurorradiologistas em um equipamento de RM de 1,5 Tesla. Os parâmetros de desfecho foram direcionados para a avaliação da detecção de impregnação pelo Gd atribuída à desmielinização aguda. Todos os exames de RM que demonstraram ao menos uma lesão com impregnação pelo Gd foram considerados positivos (RM+) e cada lesão foi analisada de acordo com suas dimensões e contraste. Resultados Trinta e seis exames de RM foram analisados. Os avaliadores demonstraram elevada concordância para a detecção de RM+ (coeficiente> 0,8), sendo excelente quanto ao número de lesões com impregnação pelo Gd (0,91 SE, 0,88 T1 MTC e 0,99 MPRAGE). A sequência T1 MTC apresentou número significativamente maior de RM+, seguida pelas sequências T1 SE e MPRAGE. De forma análoga, a sequência T1 MTC demonstrou maior acurácia na detecção de lesões com impregnação pelo Gd, seguida pelas sequências T1 SE e MPRAGE. As demais comparações demonstraram aumento estatisticamente significativo na relação de contraste e na área de impregnação pelo Gd nas imagens T1 MTC quando comparadas às imagens SE e MPRAGE. Conclusão A sequência T1 MTC com uma única dose de Gd confirmou ser a sequência mais sensível em demonstrar lesões inflamatórias agudas em equipamento de 1,5 T nessa coorte de pacientes com EM.

ABSTRACT Because of the need for a standardized and accurate method for detecting multiple sclerosis (MS) inflammatory activity, different magnetic resonance (MR) acquisitions should be compared in order to choose the most sensitive sequence for clinical routine. Objective To compare the sensitivity of a T1-weighted image to a single dose of gadolinium (Gd) administration both with and without magnetization transfer to detect contrast enhancement in active demyelinating focal lesions. Methods A sample of relapsing-remitting MS patients were prospectively examined separately by two neuroradiologists using a 1.5 Tesla scanner. The outcome parameters were focused on Gd-enhancement detection attributed to acute demyelination. All MR examinations with at least one Gd-enhancing lesion were considered positive (MR+) and each lesion was analyzed according to its size and contrast ratio. Results Thirty-six MR examinations were analyzed with a high inter-observer agreement for MR+ detection (k coefficient > 0.8), which was excellent for the number of Gd-enhancing lesions (0.91 T1 spin-echo (SE), 0.88 T1 magnetization transfer contrast (MTC) sequence and 0.99 magnetization-prepared rapid acquisition with gradient-echo (MPRAGE). Significantly more MR+ were reported on the T1 MTC scans, followed by the T1 SE, and MPRAGE scans. Confidently, the T1 MTC sequence demonstrated higher accuracy in the detection of Gd-enhancing lesions, followed by the T1 SE and MPRAGE sequences. Further comparisons showed that there was a statistically significant increase in the contrast ratio and area of Gd-enhancement on the T1 MTC images when compared with both the SE and MPRAGE images. Conclusion Single-dose Gd T1 MTC sequence was confirmed to be the most sensitive acquisition for predicting inflammatory active lesions using a 1.5 T magnet in this sample of MS patients.

Abstract In addition to findings from conventional magnetic resonance imaging, modern magnetic resonance imaging techniques have provided important information about tumor metabolism, in vivo metabolite formation, water molecule diffusion, microvascular density, and blood-brain barrier permeability, all of which have improved the in vivo diagnostic accuracy of this method in the evaluation of primary central nervous system lymphoma. These nonconventional magnetic resonance techniques are useful in the clinical practice because they enhance conventional magnetic resonance imaging by reinforcing the possibility of a diagnosis and by allowing the early detection of disease recurrence. This report is a review of the most relevant contributions of nonconventional magnetic resonance techniques to the imaging diagnosis of primary central nervous system lymphoma, the differential diagnosis of this disease, and the prognosis of patients. This paper aims to describe a wide range of presentations of primary central nervous system lymphoma, their appearance in imaging, and the differential diagnoses of this disease.

Jatropha curcas L represent a potential source of raw material for the production of biodiesel. The aim this study was to find potential candidate reference genes in J. curcas tissues. Three softwares were utilized to verify which would be the most stable reference genes in qPCR assay: GeNorm, NormFinder and BestKeeper. The most stable reference genes in developing J. curcas seeds suggested by GeNorm were GAPDH, UCP, actin. However, the best combinations of stable genes in each tissue were identified separately under stress conditions: EF1-α, PP2A2 and GAPDH in total stress, however, in SA stress, four genes were required for normalization: PP2A2, EF1-α, GAPDH and PUB. In PEG stress, four genes also were required: PP2A2, EF1-α, GAPDH and PUB, while in NaCl stress, five genes were necessary: PP2A2, GAPDH, EF1-α, PUB and Tβ2. These results are in accordance with two other programs used in this study (NormFinder, BestKeeper). In addition, the transcript levels of Jc-SRG-2 seem to be more correlated with stress responses than changes in transcript levels of Jc-SRG-1, mainly of leaves in exposure to 3-12 h on PEG and NaCl stress. Taken together, GAPDH and PP2A2 were regarded as being the best reference to provide guidelines for the selection of potential references genes under these study conditions.

RESUMO As características clínicas sobreposta da doença do neurônio motor (DNM) e demência frontotemporal (DFT) compreendem um distinto ainda não totalmente compreendido, base neurológica síndrome de sobreposição clínico-patológico foi recentemente revisto. Aqui, apresentamos uma revisão das bases clínicas, patológicas e genética de DNM-DFT e o papel da ressonância magnética no diagnóstico STI. Ao fazê-lo, discutimos as técnicas atuais que retratam o envolvimento do trato corticoespinhal seletiva (TCS) e lobo temporal em DNM-DFT.

ABSTRACT The superimposed clinical features of motor neuron disease (MND) and frontotemporal dementia (FTD) comprise a distinct, yet not fully understood, neurological overlap syndrome whose clinicopathological basis has recently been reviewed. Here, we present a review of the clinical, pathological and genetic basis of MND-FTD and the role of MRI in its diagnosis. In doing so, we discuss current techniques that depict the involvement of the selective corticospinal tract (CST) and temporal lobe in MND-FTD.

A esclerose lateral amiotrófica (ELA) é uma doença neurodegenerativa fatal que afeta os neurônios motores em regiões nas quais a ressonância magnética (RM) é frequentemente pouco informativa. Embora o tempo médio desde a manifestação inicial até o diagnóstico esteja em torno de um ano, os critérios atuais apenas recomendam o emprego da RM para excluir as "síndromes mimetizadoras da ELA". A maior aplicação da RM não convencional tem melhorado nossa compreensão sobre os mecanismos patológicos in vivo envolvidos na ELA. Estas modernas técnicas de imagem foram adicionadas à lista de potenciais biomarcadores da ELA, contribuindo para o diagnóstico e para a monitorização da progressão da doença. Esta é uma revisão detalhada da aplicabilidade clínica dos recentes avanços da neuroimagem, que visa apontar as ferramentas mais apropriadas para o diagnóstico da degeneração do neurônio motor superior (NMS).

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that affects motor neurons in the cerebral cortex, brainstem, and spinal cord, brain regions in which conventional magnetic resonance imaging is often uninformative. Although the mean time from symptom onset to diagnosis is estimated to be about one year, the current criteria only prescribe magnetic resonance imaging to exclude "ALS mimic syndromes". Extensive application of non-conventional magnetic resonance imaging (MRI) to the study of ALS has improved our understanding of the in vivo pathological mechanisms involved in the disease. These modern imaging techniques have recently been added to the list of potential ALS biomarkers to aid in both diagnosis and monitoring of disease progression. This article provides a comprehensive review of the clinical applicability of the neuroimaging progress that has been made over the past two decades towards establishing suitable diagnostic tools for upper motor neuron (UMN) degeneration in ALS.

Apesar da definição dos critérios diagnósticos específicos para identificar a síndrome radiológica isolada (SRI) sugestiva de esclerose múltipla, sua história natural ainda não foi completamente entendida. Analisamos retrospectivamente uma coorte brasileira de 12 pacientes visando a esclarecer suas características e enfatizar o papel da imagem em predizer conversão clínica. Embora alguns indivíduos não apresentem progressão em longo período de acompanhamento (16,7%), a maioria dos pacientes com SRI progrediu clínica ou radiologicamente nos primeiros anos do seguimento (83,3%). O comprometimento infratentorial e da medula espinhal, bem como o número total de lesões, foram mais relevantes em predizer a progressão que a presença de impregnação pelo gadolínio. Estudos futuros são necessários para definir o risco de conversão em homens e para esclarecer a repercussão cognitiva da SRI. Este estudo pode ampliar o entendimento da história natural e da evolução das lesões incidentais à imagem de ressonância magnética contribuindo para a adequada condução clínica da SRI.

Despite the definition of specific diagnostic criteria to identify radiologically isolated syndrome (RIS) suggestive of multiple sclerosis, its natural history remains incompletely understood. We retrospectively analyzed a Brazilian cohort of 12 patients to clarify their features and to emphasize the role of imaging predictors in clinical conversion. We demonstrated that, although some individuals did not exhibit progression over a lengthy follow-up period (16.7%), most patients will progress clinically or radiologically in the initial years of the follow-up (83.3%). Infratentorial and spinal cord involvement, as well as the total number of lesions, were more relevant predictors of progression than gadolinium enhancement. Further studies remain necessary to define the risk of conversion in males and to clarify the cognitive abilities of RIS patients. This study may provide an improved understanding of the natural course and evolution of incidental magnetic resonance imaging lesions, and further assists with the management of RIS in clinical practice.

OBJETIVO: Avaliar as características demográficas e de imagens da trombose endoluminal em uma série de pacientes submetidos a tratamento endovascular do aneurisma de aorta abdominal (TEAAA). MÉTODOS: Avaliamos as características de imagem que permitiram o diagnóstico da trombose endoluminal em uma série de 30 pacientes submetidos ao TEAAA, com seguimento de 5 a 29 meses, através de exames de tomografia computadorizada multidetectores (TCMD) de 64 canais. RESULTADOS: Foram diagnosticados dez casos de trombose luminal (33,3%), sendo que em três pacientes a trombose foi total de um ramo ilíaco. CONCLUSÃO: A TCMD permitiu o diagnóstico de diferentes tipos de trombose endoluminal em pacientes submetidos ao TEAAA. O uso desta modalidade diagnóstica minimamente invasiva deverá ser encorajado na prática clínica.

OBJECTIVE: Evaluate the imaging findings of thrombosis in a series of patients submitted to endovascular repair of aortic abdominal aneurysm. METHODS: MDCT images of 30 patients submitted to endovascular repair of aortic abdominal aneurysm were obtained by a 64 slice scanner, 5 to 29 months after the endovascular treatment. RESULTS: Thrombosis was diagnosed in 10 patients (33.3%), and in three patients thrombosis was total in an iliac branch. CONCLUSION: MDCT allowed diagnosis of different types of endoluminal thrombosis in patients submitted to endovascular repair of aortic abdominal aneurysm. Utilization of this minimally invasive diagnostic technique should be encouraged in clinical practice.

OBJECTIVE: The purpose of this study was to improve the use of 64-channel multidetector computed tomography using lower doses of ionizing radiation during follow-up procedures in a series of patients with endovascular aortic aneurysm repair. METHODS: Thirty patients receiving 5 to 29 months of follow-up after endovascular aortic aneurysm repair were analyzed using a 64-channel multidetector computed tomography device by an exam that included pre-and postcontrast with both arterial and venous phases. Leak presence and type were classified based on the exam phase. RESULTS: Endoleaks were identified in 8/30 of cases; the endoleaks in 3/8 of these cases were not visible in the arterial phases of the exams. CONCLUSION: The authors conclude that multidetector computed tomography with pre-contrast and venous phases should be a part of the ongoing follow-up of patients undergoing endovascular aortic aneurysm repair. The arterial phase can be excluded when the aneurism is stable or regresses. These findings permit a lower radiation dose without jeopardizing the correct diagnosis of an endoleak.