Table 2. The ablation study of MRI modalities and post-processing of masks on the BraTS-Reg 2022.

Method	Modality	TRE (mm)↓	Robustness↑	$\%\left|J\varphi \left(\text{p}\right)\right|\le 0$↓
DIRAC	T1ce	1.91±1.06	0.82±0.24	0.14±0.20
DIRAC-D	T1ce-T2	1.88±1.01	0.82±0.23	0.09±0.16
DIRAC-TT	T1ce-T2	1.87±0.98	0.82±0.23	0.13±0.18
DIRAC-TF	T1ce-FLAIR	1.85±0.95	0.80±0.24	0.14±0.12
DIRAC-TT-DI	T1ce-T2	1.86±1.01	0.83±0.23	0.15±0.14
DIRAC-TT-CO	T1ce-T2	1.84±0.99	0.84±0.19	0.15±0.16
DIRAC-TT-OD	T1ce-T2	1.84±0.98	0.85±0.22	0.13±0.15
DIRAC-TF-DI	T1ce-FLAIR	1.86±1.13	0.85±0.22	0.11±0.18
DIRAC-TF-CO	T1ce-FLAIR	1.85±1.08	0.82±0.23	0.13±0.20
DIRAC-TF-OD	T1ce-FLAIR	1.82±0.94	0.85±0.18	0.19±0.24

Results are provided as mean ± standard deviation. The D suffix indicates the introduction of the T2 modality through single-sided fusion input, the TT suffix indicates bimodal inputs with T1ce and T2, and the TF suffix indicates bimodal inputs with T1ce and FLAIR. DI, CO, and OD represent 3 post-processing methods for masks. ↑, higher is better; ↓, lower is better. MRI, magnetic resonance imaging; TRE, target registration error; T1ce, contrast-enhanced T1-weighted; FLAIR, fluid-attenuated inversion recovery.