Table 2.

Mean±STD of our GAN method and other traditional methods are summarized. The GTF, FPDF, and GFDF will be excluded from the quantitative comparisons as they did not transfer MRI soft-tissue contrast, add a noticeable amount of spatial distortion, and did not transfer CT bone information, respectively. Bold indicates the best results. Underline indicate a better result than ours that was excluded because it did not satisfy the fusion criteria

Method	ENT	STD	PSNR	$Q^{XY/F}$	MG	SF	NCC	MI	SSIM
GTF	5.25$\pm$0.42	0.33$\pm$0.03	4.15$\pm$3.91	0.6$\pm$0.06	$\underset{\_}{0.21\pm 0.05}$*	$\underset{\_}{0.64\pm 0.1}$*	0.82$\pm$0.12	$\underset{\_}{0.39\pm 0.21}$*	0.29$\pm$0.37
DDCT-PCA	5.13$\pm$0.3*	0.37$\pm$0.05	5.98$\pm$1.65	0.6$\pm$0.06	0.18$\pm$0.04	0.53$\pm$0.08*	0.85$\pm$0.11	0.42$\pm$0.2*	0.33$\pm$0.16
FPDE	4.77$\pm$0.34	0.27$\pm$0.05	8.46$\pm$1.65	0.37$\pm$0.10	$\underset{\_}{0.20\pm 0.04}$*	0.77$\pm$0.14	0.3$\pm$0.28	0.58$\pm$0.18	0.25$\pm$0.26
HMSD	5.58 $\mathbf{\pm }$ 0.23	0.27$\pm$0.04	5.75$\pm$1.86	0.6$\pm$0.07	0.21$\mathbf{\pm }$0.05*	0.61$\pm$0.10	0.82$\pm$0.12	0.35$\pm$0.22	0.32$\pm$ 0.17
GFDF	2.07 ± 0.51	0.23 $\pm$ 0.03	16.68 $\pm$ 1.64	0.46 $\pm$ 0.04	0.08 $\pm$ 0.02	0.37 $\pm$ 0.06	0.78 $\pm$ 0.22	$\underset{\_}{0.53\pm 0.43}$*	$\underset{\_}{0.66\pm 0.33}$*
IVF	2.74± 0.57	0.22± 0.03	12.69 ± 2.79	0.54 ± 0.04	0.11 ± 0.03	0.49 ± 0.09	0.83 ± 0.06	0.4 ± 0.36*	0.13 ± 0.05
MEF	2.06± 0.48	0.25± 0.03	20.38± 1.86	0.61± 0.06	0.06± 0.02	0.33± 0.06	0.82± 0.04	0.57 $\mathbf{\pm }$ 0.04	0.81 $\mathbf{\pm }$ 0.03
Ours	5.2$\pm$0.38	0.44 $\mathbf{\pm }$ 0.05	23.02$\mathbf{\pm }$3.5	0.64 $\mathbf{\pm }$ 0.1	0.20 $\mathbf{\pm }$ 0.05	0.67 $\mathbf{\pm }$ 0.14	0.91 $\mathbf{\pm }$ 0.04	0.42$\pm$0.29	0.62$\pm$0.22

* is not statistically different (p-value $>0.05$) from our proposed MedFusionGAN method.

Abbreviations: ENT entropy, STD standard deviation, PSNR peak signal-to-noise ratio, MG mean gradient, SF spatial frequency, NCC normalized cross-correlation, MI mutual information, SSIM structural similarity index