Fig. 1. Framework of medical image registration algorithms

Fig. 2. Schematic of characteristic points of each region

Fig. 3. Feature descriptor calculation area range

Fig. 4. Flow chart of proposed algorithm

Fig. 5. Comparison of simulation results of SIFT detection points. (a) MRI image; (b) detection points of traditional SIFT algorithm; (c) detection points of improved SIFT algorithm

Fig. 6. Effective point matching pairs of original SURF algorithm and improved SURF algorithm. (a)(b) Original SURF algorithm; (c) improved SURF algorithm

Fig. 7. MRI sequence images of T1WI, DWI, and PWI. (a)-(g) T1WI image sequences; (h)-(n) DWI image sequences; (o)-(u) PWI image sequences

Fig. 8. DCE image

Fig. 9. Registration results of T1WI, DWI, and PWI. (a)-(g) Registration results of T1WI; (h)-(n) registration results of DWI; (o)-(u) registration results of PWI

Fig. 10. T1WI sequence image registration rate

Fig. 11. DWI sequence image registration rate

Fig. 12. PWI sequence image registration rate