Development of competence in volumetric image interpretation in radiology residents

Table 4 Difference of corrected percentage-correct score between volumetric and 2D image-based test items

PGY	Volumetric item score minus 2D item score
	Mean ± SD	95% CI of the mean difference	p-value
0.5	0 ± 18	−1.9 – 2.3	n.s.
1.0	−2 ± 18	−3.8 – 0.13	n.s.
1.5	−4 ± 19	−5.9 – − 1.3	0.002
2.0	− 5 ± 19	−6.9 – − 2.8	< 0.001
2.5	− 5 ± 18	−7.3 – − 3.4	< 0.001
3.0	−2 ± 18	− 4.2 – −0.4	0.02
3.5	−3 ± 17	− 4.8 – − 1.1	0.002
4.0	−2 ± 16	−4.0 – − 0.6	0.01
4.5	−3 ± 16	− 5.1 – − 1.3	0.001
5.0	−1 ± 16	−3.1 – 0.4	n.s.

PGY indicates postgraduate year; 2D, 2-dimensional; SD, standard deviation; CI, confidence interval; n.s., not significant. PGY 0.5 indicates PGY 0–0.5; 1.0, PGY 0.5–1.0; 1.5, PGY 1.0–1.5; et cetera. Unit of ‘volumetric item score minus 2D item score’ is % points