Table 1.

R.m.s. resultant distortion values, d_rms (mm), for control experiments assessing intra-observer reproducibility of outlining.

Distortion (mm)	Control images outlined
	T2W-T2W		DWI-DWI
Study	drms	s.e.m.	drms	s.e.m.
1	0.984	0.005	1.447	0.014
2	0.765	0.007	1.065	0.017
3	0.845	0.005	0.984	0.014
4	0.905	0.006	0.749	0.016
5	0.933	0.007	0.871	0.017
6	0.732	0.007	0.932	0.017
7	0.773	0.006	0.984	0.016
8	0.673	0.006	0.999	0.015
9	0.715	0.005	0.882	0.014
10	0.722	0.005	1.022	0.014
11	0.771	0.005	0.986	0.014
12	2.239	0.007	1.219	0.021
13	0.948	0.007	1.213	0.018
14	0.718	0.006	0.898	0.015
15	0.789	0.007	0.778	0.015
16	0.699	0.005	0.799	0.013
17	0.698	0.005	0.646	0.014
18	0.650	0.006	0.682	0.014
19	0.715	0.006	0.661	0.015
20	0.518	0.006	0.726	0.015
mean (sd)	0.839 (0.348)		0.927 (0.206)

Prostate organ outlines were drawn on T2W images twice by the same observer and distortion assessed between these sets of outlines. Similarly, outlining was repeated on the set of DW images. Error on d_rms is given as the standard error on the mean; sample means are stated with standard deviation across the sample.