Landmark Optimization Using Local Curvature for Point-Based Nonlinear Rodent Brain Image Registration
Figure 3
The correction of the geometrical distortion on a B0 image (a) in EPI DTI employing the T2-wt image (b) as the reference by optimized landmarks on curves (a) and (b), and manually selected discrete landmarks (c) and (d). The colors of homologous landmarks are matched in (c) and (d). The B0 image transformed using the thin-plate splines with optimized landmarks in (a) and (b) is shown in (e), and overlaid on the T2-wt image plotted in pseudocolor (f). The average NMI and TRE of corrected B0 and T2-wt images in five image pairs (I–V) were shown in (g) and (h), respectively. NMI and TRE were calculated on the B0 images transformed using manually selected “discrete landmarks (LMs)” (black columns), landmarks generated on curves but not optimized (“Nonoptimized LMs on curves”) (white columns), curve landmarks optimized using (1) (“Optimized LMs on curves”) (gray columns), and curve landmarks manually refined (“Manually adjusted LMs”) (stripped columns) *: P < 0.1; **: P < 0.05.
