Fig. 3.

Comparison of CEST and relaxation indices for seizure lateralization. (A) Ratios of CESTR, T₁, and T₂ values in the epileptogenic HA to those in the contralateral normal HA. “∗” indicates p < 0.05. ROC curves for the lateralization of epileptic foci using the difference asymmetry index M₁ (B) and ratiometric asymmetry index M₂ (C) in the region of HA. The ROC curves include single metrics of CESTR (within 2.25–3.25 ppm), T₁, and T₂, as well as the combined CESTR and T₂ metric. As for the single metrics, the AUC values of CESTR (blue lines) are higher than those of T₁ (red lines) and T₂ (orange lines) for both M₁ and M₂ indices. Furthermore, the combined CESTR and T₂ metric (green lines) can obtain a higher accuracy of laterality prediction than the single index.