Table 2.

Summary of XFM registration errors. In all cases, registration was performed using the best eight beads. The registration error was then computed in two ways: First, over the best eight beads and then over all the high-confidence beads.

Number of projections	Error computed over eight best beads (mm)			Error computed over all high-confidence beads (mm)
	Mean±1 sd	Min	Max	Mean±1 sd	Min	Max
All (16–20)	1.16±0.52	0.07	3.18	1.50±0.87	0.07	6.26
10	1.18±0.56	0.27	3.53	1.52±0.94	0.27	5.78