Figure 9.

The figure shows the susceptibility maps generated by different dipole field inversion algorithms in axial (a–d) and sagittal (e–h) view. The susceptibility maps estimated using the TKD algorithm with a low threshold value (a, e) exhibits the characteristic streaking artifacts. By increasing the threshold value, we can see an improvement in image quality, but the contrast is reduced along with the streaking artifact (b, f). The MEDI algorithm is able to improve image quality even further, (c, g) and (d, h). By varying the regularization parameter, the susceptibility map gets smoother while the contrast is reduced (d, h). MEDI, Morphology Enabled Dipole Inversion; TKD, Truncated K-space Division.