Research Article

Quantitative Susceptibility Mapping of Magnetic Quadrupole Moments

Figure 5

Comparison between dipole and dipole + quadrupole model in the human brain. The susceptibility map from the dipole + quadrupole model shows sharper edges between white and gray matter than the map from the dipole model for both subjects 1 and 2. Consequently, the detailed structures are more clearly shown by the dipole + quadrupole model, as indicated by the yellow arrows (left). The quadrupole moment generally looks obvious at the brain structure boundaries (yellow arrow in axial Q1), but lacks contrast at some boundaries (red arrow in axial Q1). Also, in Q2, the boundary between the Putamen and Globus pallidus (yellow arrows in axial Q2) is bright on the left brain side, whereas right brain side appears dark.