RESUMO
Arterial spin labeling (ASL) is an emerging noninvasive MRI technique for assessing cerebral perfusion. An important advantage of ASL perfusion is the lack of a requirement for an exogenous tracer. ASL uses magnetically labeled water protons from arterial blood as an endogenous diffusible tracer. For this reason, ASL is an attractive perfusion imaging modality for children and for patients with contraindications or adverse reactions to gadolinium, patients with renal failure, and those who need repeated follow-up imaging. Another advantage of ASL is the possibility of quantifying cerebral blood flow, which provides an opportunity for comparative analysis among multiple longitudinal studies, unlike other MR perfusion techniques, which are semiquantitative and yield relative perfusion parameters. Advances in MRI technology and pulse sequence design have translated ASL beyond the research arena to successful clinical implementation. However, ASL is still underused in routine clinical practice. Some disadvantages of ASL include a lower signal-to-noise ratio and a longer acquisition time than those with dynamic susceptibility contrast-enhanced MRI. Additional factors limiting the use of ASL include variations in existing techniques and pulse sequence design, the complexity of implementation and postprocessing, insufficient experience with and/or knowledge of the potential clinical applications, and the absence of interpretation guidelines. The authors review the technical and physiologic basis of ASL perfusion, as well as artifacts, pitfalls, and its current clinical applications. A practical approach for interpreting ASL findings is also suggested.
Assuntos
Circulação Cerebrovascular , Angiografia por Ressonância Magnética , Criança , Humanos , Marcadores de Spin , Angiografia por Ressonância Magnética/métodos , Circulação Cerebrovascular/fisiologia , Imageamento por Ressonância Magnética/métodos , ArtefatosRESUMO
HistoryA 13-year-old girl was born to consanguineous parents. She presented with mild intellectual impairment, convergent strabismus, horizontal gaze palsy, and bilateral abducens palsy. Vertical gaze was preserved, and no abnormalities suggesting facial paralysis were noted. In addition, she reported progressive back pain since she was 5 years old. Other symptoms were denied. No medications or related drugs had been administered thus far. The patient underwent brain MRI for further evaluation. Current and previous spine radiographs were also reviewed.
Assuntos
Análise Mutacional de DNA , Oftalmoplegia Externa Progressiva Crônica/genética , Receptores de Superfície Celular/genética , Escoliose/genética , Adolescente , Consanguinidade , Feminino , Humanos , Imageamento por Ressonância Magnética , Oftalmoplegia Externa Progressiva Crônica/diagnóstico por imagem , Doenças Raras , Escoliose/diagnóstico por imagemRESUMO
HistoryA 13-year-old girl was born to consanguineous parents. She presented with mild intellectual impairment, convergent strabismus, horizontal gaze palsy, and bilateral abducens palsy. Vertical gaze was preserved, and no abnormalities suggesting facial paralysis were noted. In addition, she reported progressive back pain since she was 5 years old. Other symptoms were denied. No medications or related drugs had been administered thus far.
RESUMO
Os autores fazem uma revisão sobre a enterocolite, abordando suas manifestações clinicas, dando ênfase aos métodos de diagnósticos por imagem e sua importância no diagnóstico precoce da doença.
Assuntos
Abdome Agudo , Diagnóstico por Imagem , Enterocolite , Enterocolite Necrosante , PneumoperitônioRESUMO
Neste estudo, investigou-se a relação entre o stress, a depressão e o parto prematuro de 125 mães, entre 18 e 46 anos de idade, com ensino fundamental e ensino médio, de nível socioeconômico baixo, as quais foram divididas em dois grupos distintos: um grupo de mães de parto prematuro e outro grupo de parto a termo. Foram utilizados o Inventário de Sintomas de Strees para Adultos de Lipp, o Inventário de Depressão de Beck e um questionário sociodemográfico. Os dados revelaram que 67% das mães prematuras e 73% das mães a termo apresentaram stress na fase da resistência; e 65% das mães prematuras e 64% das mães a termo apresentaram sintomas de depressão em nível mínimo. Embora os resultados não apresentem diferenças significativas, faz-se necessário o seguimento de estudos sobre os fatores de risco relacionados ao parto prematuro para subsidiar políticas públicas de promoção à saúde e diminuir a taxa de prematuridade e morbidade neonatal.(AU)
