## 3 CAD Systems of Brain Disorders Based on Multimodal Fusion
### Multimodal Fusion Techniques Proposed in Literature: Description, Advantages and Disadvantages
)** \\ \hline \multicolumn{6}{c}{**PSNR**} \\ \cline{2-7}
[196] & Wavelet & MRI + CT & 72.1172 & & NA \\ \cline{2-7}  & Pyramid & MRI + CT & 70.1061 & & NA \\ \cline{2-7}  & Weighted average & MRI + CT & 68.4456 & & NA \\ \hline \multicolumn{6}{c}{**Mean**} & **Var** & **Entropy** & **Cros-Ent** & \\ \hline \multirow{3}{*}{[197]} & Weighted average/WT & MRI + CT & 59.6862 & 59.6871 & 6.7599 & 0.5632 & NA \\ \cline{2-7}  & Wavelet & MRI + CT & 32.0674 & 32.0678 & 5.8570 & 0.8999 & NA \\ \cline{2-7}  & Weighted average/WT & MRI + PET & 45.3537 & 45.3543 & 5.6779 & 0.7714 & NA \\ \cline{2-7}  & Wavelet & MRI + PET & 30.1334 & 30.1339 & 5.3272 & 0.9629 & NA \\ \hline \multicolumn{6}{c}{**MI**} \\ \cline{2-7}
[198] & Level set & MRI-T\({}_{1}\) + MRI-T\({}_{2}\) & 1.7176 & & NA \\ \cline{2-7}  & Pixel-based & MRI-T\({}_{1}\) + MRI-T\({}_{2}\) & 1.5540 & & NA \\ \cline{2-7}  & Edge detection & MRI-T\({}_{1}\) + MRI-T\({}_{2}\) & 1.6726 & & NA \\ \hline \multicolumn{6}{c}{**DC**} \\ \hline \multirow{3}{*}{[199]} & Bayesian multi-sequence & \multirow{3}{*}{MRI-T\({}_{1}\) + MRI-T\({}_{2}\)} & \multirow{3}{*}{12 (+8)} & \multirow{3}{*}{} & \multirow{3}{*}{} \\  & Markov model with & & + MRI-Flair & (9\% SNR) & & NA \\ \cline{2-7}  & adaptive weighted EM & & & **EFA** & **EFSA** & \\ \hline \multirow{3}{*}{[200]} & SP-MMI algorithm & MRI + SPECT & 0.001 & 0.003 & 0.007 & NA \\ \cline{2-7}  & & & **EFA** & **EFSA** & \\ \hline \multirow{3}{*}{[201]} & FCM/MMI algorithm & MRI + SPECT & 0.06 & 0.16 & 0.04 & NA \\ \cline{2-7}  & & & & **DR** & \\ \hline \multirow{3}{*}{[202]} & Regional growing & \multirow{3}{*}{MRI-T\({}_{2}\) + DTI} & \multirow{3}{*}{} & \multirow{3}{*}{} & \multirow{3}{*}{} \\  & approach & & & & & \\ \cline{1-1} \cline{5-5}  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Reference**} & \multirow{2}{*}{**Multimodal Classifier**} & \multirow{2}{*}{**ADNI Subjects**} & \multirow{2}{*}{**Modalities**} & \multicolumn{6}{c}{**Performance Criteria (\%)**} \\ \cline{5-10}  & & & & \multicolumn{3}{c}{**AD Vs. HC**} & \multicolumn{3}{c}{**MCI Vs. HC**} \\ \cline{5-10}  & & & & **AC** & **SE** & **SP** & **AUC** & **AC** & **SE** & **SP** & **AUC** \\ \hline
[16] & HIS & NA & MRI + PET & 80-90 & NA & NA & NA & NA & NA & NA & NA \\ \hline \multirow{3}{*}{[10]} & \multirow{3}{*}{MKL} & MRI & 86.2 & 86.0 & 86.3 & NA & 72.0 & 78.5 & 59.6 & NA \\  & & CSF & 82.1 & 81.9 & 82.3 & NA & 71.4 & 78.0 & 58.8 & NA \\  & & 51 AD + 99 MCI + & PET & 86.5 & 86.3 & 86.6 & NA & 74.5 & 81.8 & 66.0 & NA \\  & & 52 HC & MRI + FDG-PET & 90.6 & 91.4 & 91.6 & NA & 76.4 & 80.4 & 63.3 & NA \\  & & & MRI + FDG-PET + CSF & 93.2 & NA & NA & NA & NA & NA & NA & NA \\ \hline \multirow{3}{*}{[203]} & \multirow{3}{*}{MKL} & 72 AD + & MRI & 75.27 & 63.06 & 81.86 & 82.84 & NA & NA & NA & NA \\  & & 82 HC & FDG-PET & 79.36 & 78.61 & 78.94 & 83.9 & NA & NA & NA & NA \\  & & MRI + FDG-PET & 81.0 & 78.52 & 81.76 & 88.5 & NA & NA & NA & NA \\ \hline \multirow{3}{*}{[204]} & \multirow{3}{*}{MKL} & 48 AD + 66 HC & MRI + FDG-PET & & & & & & & & \\  & 48 AD + 66 HC & MRI + FDG-PET + CSF + & & & & & & & & \\  & 490A + 6 Cognitive scores & & & & & & & & & \\ \hline \multirow{3}{*}{[205]} & \multirow{3}{*}{SCLDA model} & 49 AD + 67 HC & MRI + FDG-PET & 94.3 & NA & NA & NA & NA & NA & NA \\ \hline \multirow{3}{*}{[206]} & \multirow{3}{*}{MST} & MRI & 84.8 & NA & NA & NA & 73.9 & NA & NA & NA \\  & & 50 HC & CSF & 84.5 & NA & NA & NA & 79.7 & NA & NA & NA \\  & & 50 HC & CSF & 80.5 & NA & NA & NA & 53.6 & NA & NA & NA \\  & & MRI + FDG-PET + CSF & 93.3 & NA & NA & NA & 83.2 & NA & NA & NA \\ \hline \multirow{3}{*}{[207]} & \multirow{3}{*}{Multivariate analysis of \(\,\