Table 2.

The mean, median, standard deviation (STD) and range ([min, max]) of the absolute difference in the inter-marker distances (IDs) of the precisely located FMs between CT and MRI for all the single observers and for all the five observers

Sequence	Observer	Mean	Median	STD	Range
Single	1	0.8	0.6	0.7	[0.1, 3.1]
	2	0.6	0.5	0.5	[0.0, 2.5]
	3	0.7	0.6	0.5	[0.0, 2.1]
	4	0.7	0.6	0.6	[0.1, 2.9]
	5	0.7	0.5	0.6	[0.1, 2.5]
	All	0.7	0.6	0.6	[0.0, 3.1]
Multiple	1	0.7	0.4	0.6	[0.0, 2.7]
	2	0.6	0.4	0.6	[0.0, 3.0]
	3	0.7	0.5	0.7	[0.0, 2.5]
	4	0.7	0.5	0.6	[0.0, 2.8]
	5	0.7	0.6	0.5	[0.0, 2.5]
	All	0.6	0.5	0.6	[0.0, 3.0]

The results were calculated excluding 10/48 and 3/48 FMs for the localisation performed on a single and multiple sequences, respectively. All the values are expressed in mm