Table 4.

Comparison between the relative errors (REs) and target registration errors (TREs) for images and deformation vector fields (DVFs) solved by 2D3D-RegNet, using different offset angles at test time. Four scan angle scenarios were included in this evaluation: single-view 30°, ortho-view 30°, single-view 90° and ortho-view 90° (Fig. 3). The networks were separately trained on the four scan angle scenarios, with angle directions specified in Fig. 3. During testing, the scan angles were collectively offset by magnitudes ranging from 0° to 25°.

		off 0°	off 5°	off 10°	off 15°	off 20°	off 25°
30° (Single-view)	RE/%	17.7 ± 2.8	17.7 ± 2.8	18.0 ± 2.8	18.4 ± 2.9	18.8 ± 2.9	19.4 ± 3.0
	TRE/mm	4.6 ± 3.5	4.6 ± 3.5	4.7 ± 3.6	4.8 ± 3.8	5.0 ± 3.9	5.2 ± 4.1
30° (Ortho-view, 15° each)	RE/%	15.4 ± 2.5	15.6 ± 2.4	15.9 ± 2.5	16.2 ± 2.5	16.8 ± 2.6	17.2 ± 2.6
	TRE/mm	4.5 ± 3.4	4.5 ± 3.4	4.6 ± 3.5	4.6 ± 3.6	4.7 ± 3.7	4.8 ± 3.8
90° (Single-view)	RE/%	15.3 ± 2.4	15.4 ± 2.4	15.7 ± 2.4	16.0 ± 2.4	16.3 ± 2.5	16.6 ± 2.5
	TRE/mm	4.3 ± 3.3	4.3 ± 3.4	4.4 ± 3.4	4.5 ± 3.5	4.6 ± 3.6	4.7 ± 3.8
90° (Ortho-view, 45° each)	RE/%	14.4 ± 2.1	14.3 ± 2.1	14.4 ± 2.1	14.5 ± 2.2	14.8 ± 2.2	15.2 ± 2.3
	TRE/mm	3.9 ± 3.0	3.9 ± 3.0	4.0 ± 3.0	4.0 ± 3.1	4.0 ± 3.1	4.1 ± 3.1