Methods, devices, apparatus and systems for magnetic resonance imaging with deep neural networks are provided. In one aspect, a method of magnetic resonance imaging method combines a deep neural network and an accelerated imaging manner. The method includes: scanning a subject with a first undersampling factor and a first sampling trajectory to obtain first imaging information, processing the first imaging information with the deep neural network to obtain second imaging information corresponding to a second undersampling factor that is smaller than the first undersampling factor, and reconstructing a magnetic resonance image of the subject from the second imaging information.