Polar plate and magnetic resonance imaging magnet with polar plate

The invention provides a polar plate and a magnetic resonance imaging magnet with the polar plate. A compensation ring and a stretching ring which are concentric are arranged on the inner surface of the polar plate facing a patient space; both the compensation ring and the stretching ring are convex rings; the compensation ring is located inside the stretching ring and in the middle of the inner surface; the stretching ring is located at the edge of the inner surface; a groove is formed between the compensation ring and the stretching ring. The polar plate provided by the invention not only can expand the range of an imaging area, but also can keep the original magnetic field uniformity from being destroyed, so that the weight of the magnet can be greatly reduced under the same imaging range. The polar plate can be applied to various magnetic resonance imaging magnets. 本发明提供了一种极板及具有该极板的磁共振成像磁体。该极板朝向患者空间的内表面上设有同心的补偿环和拉伸环，所述补偿环和拉伸环均为凸环，其中补偿环位于拉伸环内部，处于所述内表面的中间位置；拉伸环位于所述内表面边缘；且补偿环和拉伸环之间还设有凹槽。本发明的极板既可以扩大成像区范围又可以保持