Magnetic resonance imaging apparatus, quantitative susceptibility mapping method, computer, susceptibility distribution calculation method, and susceptibility distribution calculation program

摘要

Provided is a technique for reducing artifacts and noise and improving the accuracy of a calculated magnetic susceptibility distribution by simple processing when calculating the magnetic susceptibility distribution using MRI. In this technique, first, a magnetic field distribution is obtained from a complex image acquired by MRI via a phase image. Next, the smoothing process is repeatedly performed on the magnetic susceptibility distribution calculated from the magnetic field distribution under the constraint condition based on the relational expression between the magnetic field and the magnetic susceptibility. Specifically, the magnetic susceptibility distribution is calculated by a minimization process that minimizes an error function defined by a predetermined initial magnetic susceptibility distribution and a magnetic field distribution by repeated calculation. At this time, the updated susceptibility distribution calculated based on the error function during the minimization process is smoothed every time the updated susceptibility distribution is calculated.