Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Magn Reson Med Sci ; 19(2): 154-158, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-31142703

RESUMEN

The silent navigator technique utilizes a non-selective excitation and an appropriate respiratory waveform generation method is necessary for an accurate motion detection. We compared three methods for silent navigator waveform generation. The profile generation method with coil selection (prof-selection) resulted in a high cross correlation with bellows signals and a large respiration amplitude. The prof-selection method should be used for silent navigator waveform generation.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Procesamiento de Señales Asistido por Computador , Humanos , Respiración
2.
Magn Reson Med ; 79(4): 2170-2175, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-28782173

RESUMEN

PURPOSE: To develop and demonstrate the feasibility of a silent respiratory navigator technique for prospective triggering, which was incorporated into a three-dimensional radial zero-echo-time sequence for respiratory navigated silent abdominal imaging. METHODS: A nonselective hard excitation radiofrequency pulse was used for the navigator sequence with a derated readout gradient, to avoid generation of high levels of acoustic noise. The acquired navigator signals were processed in real time and used for prospective triggering of the zero-echo-time sequence. Ten healthy volunteers were scanned using the proposed and conventional techniques at 1.5 T. An acoustic noise measurement with A-weighted continuous equivalent sound pressure level was also performed. RESULTS: The sound pressure-level values of the background noise, zero-echo-time imaging, conventional, and silent navigators were 68.3, 68.4, 102.5, and 69.4 dBA, respectively. Excellent correlation with correlation coefficients greater than 0.9 was observed between the bellows signals and displacement values calculated from the navigators. Sharpness of the portal vein of both conventional and silent navigator-triggered images was significantly higher than those of nontriggered images. CONCLUSIONS: The silent navigator-triggered zero-echo-time technique is feasible and might improve image quality and workflow of abdominal MRI of patients who are prone to acoustic noise. Magn Reson Med 79:2170-2175, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Asunto(s)
Abdomen/diagnóstico por imagen , Imagenología Tridimensional , Imagen por Resonancia Magnética , Acústica , Algoritmos , Artefactos , Voluntarios Sanos , Humanos , Interpretación de Imagen Asistida por Computador , Movimiento (Física) , Oscilometría , Presión , Reproducibilidad de los Resultados , Respiración , Procesamiento de Señales Asistido por Computador
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA