1. A method for generating an image representing a magnetic susceptibility distribution for an object using magnetic resonance imaging (MRI), the method comprising: determining, by a processing device, phase information corresponding to magnetic signals emitted by the object after the object is excited by a magnetic field; determining, by the processing device, additional information corresponding to the object independent from the phase information, wherein the additional information is one of: (a) magnitude information corresponding to the emitted magnetic signals and (b) prior information regarding the object; and generating, by the processing device, the image representing the magnetic susceptibility distribution for the object based on the determined phase information and the determined additional information, wherein the generating comprises: performing a direct inversion of a convolution operation using a system matrix, the determined phase information, and the additional information, wherein the additional information is used to improve the system matrix.