In Vivo Mapping and Quantification of Creatine Using Chemical Exchange Saturation Transfer Imaging in Rat Models of Epileptic Seizure

PurposeTo evaluate signal changes in the hippocampus of epileptic seizure rat models, based on quantified creatine chemical exchange saturation transfer (CrCEST) signals.ProceduresCEST data and H-1 magnetic resonance spectroscopy (H-1 MRS) data were obtained for the two imaging groups: control (CTRL) and epileptic seizure-induced (ES; via kainic acid [KA] injection) groups. CrCEST signals in the hippocampal regions were quantitatively evaluated; correlations between CrCEST signals and phosphocreatine (PCr) and total creatine (tCr; PCr+Cr) concentrations, derived from the analysis of H-1 MRS data, were investigated as a function of time changes (before KA injection, 3 and 5h after KA injection).ResultsMeasured CrCEST signals were exhibited significant differences between before and after KA injection in the ES group. At each time point, CrCEST signals showed significant correlations with PCr concentration (all |r|>0.59; all P<0.05); no significant correlations were found between CrCEST signals and tCr concentrations (all |r|<0.22; all P>0.05).ConclusionsCrCEST can adequately detect changes in the concentration of Cr as a result of energy metabolism, and may serve as a potentially useful tool for diagnosis and assessment of prognosis in epilepsy.