一种超低场磁共振成像的磁场屏蔽装置

A Magnetic Shield Equipment for Ultra-low Field MRI

与常规磁共振成像相比,超低场磁共振成像不仅大大降低了设备的成本和体积,还能够获得普通高场核磁共振成像无法得到的特殊信息。由于超低场磁共振信号是一种非常微弱的低频信号,特别容易受到外界磁场的影响,并且由于编码磁场很低,环境磁场及其梯度的存在都会影响到磁共振信号的检测,因此在检测时需要对周围环境磁场噪声进行有效屏蔽并且对环境磁场及其梯度进行有效补偿。本文介绍了一种无源屏蔽和有源补偿相结合的方法,可以达到良好的磁场屏蔽效果。

Compared with conventional magnetic resonance imaging （MRI） system,ultra-low field MRI not only reduces the cost and size of the equipment, but also makes it possible to obtain special images which are impossible to be obtained by ordinary high field MRI equipment. Because ultra-low field MRI has a very weak signal, the magnetic shield is important for signal detection. This paper proposes a magnetic shield method for ultra-low field MRI signal detection, which is a passive magnetic shield combined with active magnetic compensation method. The method can effectively reduce the impact of the environmental magnetic field for signal detection.