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1.
Pflugers Arch ; 462(4): 587-97, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21796340

RESUMO

This article presents a novel model of acupuncture physiology based on cellular calcium activation by an acoustic shear wave (ASW) generated by the mechanical movement of the needle. An acupuncture needle was driven by a piezoelectric transducer at 100 Hz or below, and the ASW in human calf was imaged by magnetic resonance elastography. At the cell level, the ASW activated intracellular Ca(2+) transients and oscillations in fibroblasts and endothelial, ventricular myocytes and neuronal PC-12 cells along with frequency-amplitude tuning and memory capabilities. Monitoring in vivo mammalian experiments with ASW, enhancement of endorphin in blood plasma and blocking by Gd(3+) were observed; and increased Ca(2+) fluorescence in mouse hind leg muscle was imaged by two-photon microscopy. In contrast with traditional acupuncture models, the signal source is derived from the total acoustic energy. ASW signaling makes use of the anisotropy of elasticity of tissues as its waveguides for transmission and that cell activation is not based on the nervous system.


Assuntos
Estimulação Acústica , Terapia por Acupuntura , Sinalização do Cálcio/fisiologia , Músculo Esquelético/fisiologia , Adulto , Animais , Anisotropia , Técnicas de Imagem por Elasticidade , Humanos , Masculino , Camundongos , Modelos Teóricos , Células NIH 3T3 , Células PC12 , Ratos , Coxa da Perna
2.
J Magn Reson Imaging ; 32(5): 1248-54, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21031532

RESUMO

PURPOSE: To determine the optimal method to correct air and tissue susceptibility differences in the head and neck to allow proton ((1)H) chemical shift imaging (CSI) to be performed at 3T. MATERIALS AND METHODS: Shimming protocols (iterative, first-order, and second-order) and perfluorocarbon (PFC) pads were evaluated using water peak linewidth measurements obtained from single-voxel magnetic resonance spectroscopy (MRS) on a head and neck phantom. After optimization of the technique, CSI was then tested on 14 patients with head and neck tumors. RESULTS: Second-order shimming (water peak linewidth, 4.6 Hz) performed significantly (P < 0.001) better than first-order (16.5 Hz) and iterative shimming (18 Hz) and the water peak linewidth was significantly reduced using PFC pads (P < 0.001). Using second-order shimming and PFC pads, CSI was successful in 10 patients with nodal metastases (n = 8) and benign tumors (n = 2) and unsuccessful in four patients with primary tumors along the aerodigestive tract. CONCLUSION: Proton CSI can be successfully performed in the head and neck using second-order shimming and PFC pads to correct air and tissue susceptibility differences. CSI was more successfully performed on nodal metastases, while CSI for primary tumors along the aerodigestive tract remains a challenge.


Assuntos
Neoplasias de Cabeça e Pescoço/diagnóstico , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética , Adulto , Idoso , Colina/análise , Feminino , Cabeça/patologia , Neoplasias de Cabeça e Pescoço/química , Humanos , Metástase Linfática , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Pescoço/patologia , Imagens de Fantasmas
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