Longitudinal metabolic assessment for neonatal ischemic stroke in rat brain using CEST-MRI

Motivation: Chemical exchange saturation transfer (CEST) has been employed for studying pH changes in acute phase of neonatal arterial ischemic stroke (NAIS), but not for long-term effects. Goal(s): This study aimed to achieve longitudinal monitoring of NAIS evolution. Approach: We constructed a 7-day-old NAIS rat model and explored the changes of brain metabolites by CEST-MRI. Contrast maps for contributing metabolites were calculated using Lorentzian Difference (LD) methods. Results: All LD-quantified CEST contrast maps exhibit significant increase as age growth, in both sham group and the contralateral brain in NAIS group; Whereas the ischemic hemisphere displayed lower signals than the contralateral sides in NAIS group . Impact: CEST signals displayed significant elevation over from 3h to 5w after surgery for both sham group and the contralateral brain tissue in NAIS group. This suggests the potential of CEST in sensitive and comprehensive assessment in NAIS diagnosis and management.