Encontrados 11 documentos, a visualizar página 1 de 2
Applications of the Dixon technique in the evaluation of the musculoskeletal sy...
Lins,Carolina Freitas; Salmon,Carlos Ernesto Garrido; Nogueira-Barbosa,Marcello HenriqueAbstract The acquisition of images with suppression of the fat signal is very useful in clinical practice and can be achieved in a variety of sequences. The Dixon technique, unlike other fat suppression techniques, allows the signal of fat to be suppressed in the postprocessing rather than during acquisition, as well as allowing the visualization of maps showing the distribution of water and fat. This review of...
Anatomic and neuropsychological findings in low-educated cognitively intact eld...
Foss,Maria Paula; Diniz,Paula Rejane Beserra; Roza,Daiane Leite da; Gefen,Tamar; Maher,Amanda Cook; Formigheri,Paulo; Spedo,Carina T.ABSTRACT In elderly individuals, low educational level may represent a risk factor for the development of dementia and a proxy of cognitive reserve. Objective: This study examined the cognitive and neuroanatomic correlates of high versus low educational levels in cognitively healthy community-dwelling older adults in Brazil. Methods: Fifty-three older adults (mean age: 68±5.3 years) were divided into a “low edu...
Quantitative MRI data in Multiple Sclerosis patients: a pattern recognition study
Pessini,Rodrigo Antonio; Santos,Antonio Carlos dos; Salmon,Carlos Ernesto GarridoAbstract Introduction Multiple Sclerosis (MS) is a neurodegenerative disease characterized by inflammatory demyelination in the central nervous system. Quantitative Magnetic Resonance Imaging (qMRI) enables a detailed characterization of brain tissue, but generates a large number of numerical results. In this study, we elucidated the main qMRI techniques and the brain regions that allow the identification of MS...
Pattern recognition of abscesses and brain tumors through MR spectroscopy: Comp...
Vieira,Bruno Hebling; Santos,Antonio Carlos dos; Salmon,Carlos Ernesto GarridoAbstract Introduction The interpretation of brain tumors and abscesses MR spectra is complex and subjective. In clinical practice, different experimental conditions such as field strength or echo time (TE) reveal different metabolite information. Our study aims to show in which scenarios magnetic resonance spectroscopy can differentiate among brain tumors, normal tissue and abscesses using classification algori...
Enhancing quality in Diffusion Tensor Imaging with anisotropic anomalous diffus...
Senra Filho,Antonio Carlos da Silva; Salmon,Carlos Ernesto Garrido; Santos,Antonio Carlos dos; Murta Junior,Luiz OtávioAbstract Introduction: Diffusion tensor imaging (DTI) is an important medical imaging modality that has been useful to the study of microstructural changes in neurological diseases. However, the image noise level is a major practical limitation, in which one simple solution could be the average signal from a sequential acquisition. Nevertheless, this approach is time-consuming and is not often applied in the cl...
Does a small size needle puncture cause intervertebral disc changes?
Issy,Ana Carolina; Castania,Vitor; Silveira,Joao Walter; Nogueira-Barbosa,Marcello Henrique; Salmon,Carlos Ernesto Garrido; Del-Bel,ElainePURPOSE:Small size needles have been regularly used for intradiscal injection of innocuous/potential therapeutic compounds in experimental conditions, but also in clinic procedures, such as discography. Our aim was to investigate if a 30-gauge needle could trigger observable changes on intact intervertebral discs. We compared these effects to those induced by a large size needle (21-gauge), a well-known interve...
Susceptibility weighted imaging: differentiating between calcification and hemo...
Barbosa,Jeam Haroldo Oliveira; Santos,Antonio Carlos; Salmon,Carlos Ernesto GarridoObjective:To present a detailed explanation on the processing of magnetic susceptibility weighted imaging (SWI), demonstrating the effects of echo time and sensitive mask on the differentiation between calcification and hemosiderin.Materials and Methods:Computed tomography and magnetic resonance (magnitude and phase) images of six patients (age range 41– 54 years; four men) were retrospectively selected. The SW...
Evaluation of nuclear magnetic resonance spectroscopy variability
Barreto,Felipe Rodrigues; Otaduy,Maria Concepción García; Salmon,Carlos Ernesto GarridoINTRODUCTION: The intrinsically high sensitivity of Magnetic Resonance Spectroscopy (MRS) causes considerable variability in metabolite quantification. In this study, we evaluated the variability of MRS in two research centers using the same model of magnetic resonance image scanner. METHODS: Two metabolic phantoms were created to simulate magnetic resonance spectra from in vivo hippocampus. The phantoms were f...
Simulação de espectros de ressonância paramagnética eletrônica (RPE) através do...
Salmon,Carlos Ernesto Garrido; Sousa Neto,Diógenes de; Tabak,Marcel; Costa Filho,Antonio José daEPR users often face the problem of extracting information from frequently low-resolution and complex EPR spectra. Simulation programs that provide a series of parameters, characteristic of the investigated system, have been used to achieve this goal. This work describes the general aspects of one of those programs, the NLSL program, used to fit EPR spectra applying a nonlinear least squares method. Several mot...
Optimization of saddle coils for magnetic resonance imaging
Salmon,Carlos Ernesto Garrido; Vidoto,Edson Luiz Géa; Martins,Mateus José; Tannús,AlbertoIn Nuclear Magnetic Resonance (NMR) experiments, besides the apparatus designed to acquire the NMR signal, it is necessary to generate a radio frequency electromagnetic field using a device capable to transduce electromagnetic power into a transverse magnetic field. We must generate this transverse homogeneous magnetic field inside the region of interest with minimum power consumption. Many configurations have ...