Table 1.

Dice values, average surface distance (ASD), and registration time of Rectum in pelvic cases before registration, after registration.

Rectum	Before registration		Elastix		MIM		FCN with cycle‐consistent (our method)		FCN without cycle‐consistent
	Dice	ASD (mm)	Dice	ASD (mm)	Dice	ASD (mm)	Dice	ASD (mm)	Dice	ASD (mm)
Case1	0.26	13.26	0.71	4.58	0.68	5.72	0.71	4.30	0.76*	3.86*
Case2	0.42	10.56	0.82*	2.59*	0.62	5.17	0.70	3.18	0.75	3.88
Case3	0.48	15.04	0.81*	3.82	0.76	4.07	0.75	3.51*	0.75	4.35
Case4	0.59	10.43	0.66	6.58	0.72	3.64	0.87*	1.54*	0.86	1.70
Case5	0.54	14.57	0.82	3.21	0.84*	2.63*	0.77	3.55	0.79	3.67
Case6	0.10	18.95	0.69	2.22	0.53	3.07	0.75*	1.58*	0.44	3.68
Case7	0.46	10.11	0.88	2.77	0.67	5.94	0.85	1.98*	0.89*	2.18
Case8	0.53	14.72	0.60	5.99	0.69	4.44	0.91*	1.15*	0.74	3.84
Case9	0.60	21.18	0.82	4.58	0.89*	2.96	0.89*	2.82*	0.88	3.06
Case10	0.35	13.03	0.80	3.63	0.88*	2.26*	0.83	2.94	0.75	4.08
Average result	0.43	14.19	0.76	4.00	0.73	3.99	0.80	2.66	0.76	3.43
Standard deviation	0.16	3.63	0.09	1.44	0.12	1.30	0.08	1.04	0.13	0.86
Average time	/		64 s		28 s		<0.1 s		<0.1 s

The * indicates the best Dice value or best ASD in the corresponding test case.