Numerical study of remote detection outside the magnet with travelling wave Magnetic Resonance Imaging at 3T

7th International Congress of Engineering Physics

物理学;工业技术

López, M.^1 ; Vázquez, F.^2 ; Solís-Nájera, S.^2 ; Rodriguez, A.O.^3

Departamento de Ciencias Basicas, Universidad Autónoma Metropolitana Azcapotzalco, México DF, Mexico^1

Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, Mexico DF

04510, Mexico^2

Departamento de Ingeniería Eléctrica, Universidad Autonoma Metropolitana Iztapalapa, México DF

09340, Mexico^3

关键词: Circular surfaces;    Clinical scanners;    Electromagnetic field simulation;    High magnetic fields;    Lower frequencies;    Numerical results;    Parallel plate waveguide;    Signal transmission;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/582/1/012037/pdf
DOI  :  10.1088/1742-6596/582/1/012037

学科分类：工业工程学

来源: IOP

【 摘 要 】

The use of the travelling wave approach for high magnetic field magnetic resonance imaging has been used recently with very promising results. This approach offer images one with greater field-of-view and a reasonable signal-to-noise ratio using a circular waveguide. This scheme has been proved to be successful at 7 T and 9.4 T with whole-body imager. Images have also been acquired with clinical magnetic resonance imaging systems whose resonant frequencies were 64 MHz and 128 MHz. These results motivated the use of remote detection of the magnetic resonance signal using a parallel-plate waveguide together with 3 T clinical scanners, to acquired human leg images. The cut-off frequency of this waveguide is zero for the principal mode, allowing us to overcome the barrier of transmitting waves at lower frequency than 300 MHz or 7 T for protons. These motivated the study of remote detection outside the actual magnet. We performed electromagnetic field simulations of a parallel-plate waveguide and a phantom. The signal transmission was done at 128 MHz and using a circular surface coil located almost 200 cm away for the magnet isocentre. Numerical simulations demonstrated that the magnetic field of the principal mode propagate inside a waveguide outside the magnet. Numerical results were compared with previous experimental-acquired image data under similar conditions.