Longitudinal changes of the GQI indices in the different brain compartments after irradiation.

(A) In the cerebral cortex, there was no clear trend in the GFA R/L ratio. The QA and ISO R/L ratios showed a rapid increase after the 1^st week followed by a plateau and then a gradual decrease. (B) In the external capsule, the GFA R/L ratio showed a gradual decrease during the initial 2 weeks followed by a gradual recovery. The QA and ISO ratios showed a rapid increase during the initial 2 weeks followed by a plateau and then a gradual decrease. (C) In the hippocampus, there was no clear trend in the GFA R/L ratio. The QA and ISO R/L ratios showed a rapid increase after the 1^st week followed by a plateau and then a gradual decrease. (D) In the thalamus, there was no clear trend in the GFA R/L ratio. The QA and ISO R/L ratios showed a rapid increase at the 1^st week followed by a plateau and then a gradual decrease.