Table 1.

Summary of registration methods and references.

Method	Model	References	Comments
1	Thin-plate splines	22	Cropped to foam
2	Thin-plate splines	31, 32, 33	No cropping or masking
3	B-splines	34, 35	No cropping—Masked the vertebrae
4	B-splines	36	No cropping—Masked the vertebrae
5	B-splines	30, 37	Cropped to foam
6	Demons algorithm	15, 38	No cropping or masking
7	Fluid flow	1, 39, 41	No cropping or masking
8	Free form with calculus of variations	40	No cropping or masking