Table 3.

Three sets of five needles were inserted into the template at known depths and reconstructed. This comparison gives us the cumulative 3D error from X-ray reconstruction with respect to FTRAC and FTRAC-template registration, i.e. 3D reconstruction error with respect to the template.

Trial number	Error type	Error (mm)			3D error (mm)	Translation offset (mm)
		X	Y	Z
1	Absolute	0.32	0.70	0.84	1.16	1.15
2		0.66	0.29	1.02	1.27	1.22
3		0.12	0.28	0.54	0.65	0.55
1	Relative	0.11	0.17	0.05	0.22	–
2		0.10	0.27	0.35	0.49	–
3		0.10	0.27	0.19	0.36	–