RESUMO
BACKGROUND AND PURPOSE: MRA assessment of parent artery patency after flow-diverter placement is complicated by imaging artifacts produced by these devices. The purpose of this study was to assess the accuracy of liver acquisition with volume acceleration-flex technique (LAVA-Flex) MRA in combination with 3D-TOF with HyperSense MRA for the evaluation of parent vessel status after intracranial flow-diverter placement. MATERIALS AND METHODS: Fifty-six patients treated by flow diversion and followed with both DSA and 3T MRA between November 2020 and August 2021 were included. All patients were evaluated for parent artery patency using the same imaging protocol (DSA, noncontrast MRA including 3D-TOF with HyperSense and LAVA-Flex, and contrast-enhanced MRA, including time-resolved imaging of contrast kinetics MRA and delayed contrast-enhanced MRA). RESULTS: With DSA as a criterion standard to evaluate the patency of the parent vessel, noncontrast MRA had a good specificity (0.83) and positive predictive value (0.65), better than contrast-enhanced MRA (0.55 and 0.41, respectively). Both had excellent sensitivity and negative predictive value: noncontrast MRA, 0.93 and 0.97, respectively; contrast-enhanced MRA, 0.93 and 0.96, respectively. Specificity and positive predictive value tended to be lower for patients treated with additional devices than for those treated with flow diverters exclusively and for patients treated with a specific type of flow diverter. CONCLUSIONS: Noncontrast MRA can be used for noninvasive follow-up of intracranial aneurysms treated by flow diverters. The combined use of LAVA-Flex and 3D-TOF with HyperSense sequences allows monitoring the status of the parent artery and aneurysm occlusion.
Assuntos
Embolização Terapêutica , Aneurisma Intracraniano , Angiografia Digital/métodos , Artérias , Meios de Contraste , Seguimentos , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/cirurgia , Angiografia por Ressonância Magnética/métodos , Sensibilidade e Especificidade , Resultado do TratamentoAssuntos
Analgésicos/uso terapêutico , Drogas em Investigação/uso terapêutico , Neuralgia/tratamento farmacológico , Analgésicos/farmacocinética , Analgésicos/farmacologia , Animais , Biotransformação/genética , Ensaios Clínicos como Assunto/métodos , Método Duplo-Cego , Avaliação Pré-Clínica de Medicamentos/métodos , Resistência a Medicamentos/genética , Drogas em Investigação/farmacocinética , Drogas em Investigação/farmacologia , Feminino , Genótipo , Humanos , Masculino , Estudos Multicêntricos como Assunto/métodos , Canal de Sódio Disparado por Voltagem NAV1.7/genética , Neuralgia/fisiopatologia , Nociceptores/efeitos dos fármacos , Polimorfismo de Nucleotídeo Único , Projetos de Pesquisa , Especificidade da EspécieRESUMO
Neuroimaging plays a central role in the assessment of patients with acute ischemic stroke. Within a few minutes, modern multimodal imaging protocols can provide one with comprehensive information about prognosis, management, and outcome of the disease, and may detect changes in the intracranial structures reflecting severity of the ischemic injury depicted by four Ps: parenchyma (of the brain), pipes (i.e., the cerebral blood vessels), penumbra, and permeability (of the blood brain barrier). In this article, we have reviewed neuroradiological predictors of malignant middle cerebral artery infarction and hemorrhagic transformation in light of the aforementioned four Ps.
RESUMO
Foram comparados dois métodos não-invasivos de medida da pressão arterial, o Doppler vascular e o oscilométrico, com o objetivo de estabelecer parâmetros que possam auxiliar no diagnóstico seguro da hipertensão arterial. Para tal, foram utilizados 45 cães, machos e fêmeas, distribuídos em três grupos de acordo com o peso, pequeno, médio e grande porte. Em cada animal, procedeu-se a mensuração por meio do Doppler vascular e, em seguida, do oscilométrico. Na obtenção da pressão arterial sistólica, não houve diferença entre os métodos nos três grupos de animais, porém, na obtenção da pressão arterial diastólica, houve diferença estatística entre o Doppler vascular e o oscilométrico nos grupos de animais de pequeno e médio porte. Pôde-se concluir que valores confiáveis de pressão sistólica podem ser obtidos tanto por meio do Doppler vascular quanto do oscilométrico. Os valores da pressão arterial diastólica obtidos pelos dois métodos não se correlacionam, principalmente nos animais de pequeno e médio porte.
Two noninvasive methods for blood pressure measurement, the oscilometric and the Doppler ultrasonic, were compaired aiming the establishment of parameters that can be helpful for the hypertension diagnosis. Forty-five dogs, males and females, were distributed in three groups, according to body weight: small, medium, and large sizes. In each animal, measurement of the blood pressure was performed, first by the Doppler ultrasonic, followed by the oscilometric method. No differences were observed in sistolic arterial pressure values obtained by both methods in none of the three animal groups. However, there was an important difference in diastolic arterial pressure values obtained by these methods, especially in small and medium size dogs. It was concluded that reliable results of sistolic blood pressure can be obtained both by the Doppler ultrasonic and the oscilometric method. Diastolic blood pressure results, however, showed no correlation between these two methods, mainly in small and medium size dogs.