Magnetic resonance imaging apparatus, quantitative susceptibility mapping method, computer, susceptibility distribution calculation method, and susceptibility distribution calculation program
Provided is a technique in calculating a magnetic susceptibility distribution by using an MRI, for reducing artifacts and noise and improving precision in the magnetic susceptibility distribution being calculated. According to this technique, a magnetic field distribution is obtained via a phase image from a complex image acquired through MRI. Under the constraint based on a relational expression between the magnetic field and the magnetic susceptibility, smoothing process is performed iteratively on the magnetic susceptibility distribution calculated from the magnetic field distribution. Specifically, a minimization process for minimizing through the iterative operation, an error function defined by a predetermined initial magnetic susceptibility distribution and the magnetic field distribution is performed, thereby calculating the magnetic susceptibility distribution. At this time, an updated magnetic susceptibility distribution calculated based on the error function during the minimization process is smoothed, every time the updated magnetic susceptibility distribution is calculated.
