In Vivo Assessment of Cerebral Functional Changes in a Rat Model of Sepsis-Associated Encephalopathy Using Multi-Parametric MR Imaging

Sepsis-associated encephalopathy (SAE) results in widespread brain dysfunction due to systemic infection without direct central nervous system involvement. This study aimed to assess functional and metabolic alterations in a rat model of SAE using multi-parametric magnetic resonance imaging (mpMRI). Twenty-one rats were divided into control (CTRL, n = 7), SAE05 (5 mg/kg LPS, n = 7), and SAE10 (10 mg/kg LPS, n = 7) groups. MPI was performed 24 h post-LPS injection using a 7 T MR system to capture apparent diffusion coefficient (ADC), cerebral blood flow (CBF), T1, and T2 maps. In our study, the ADC and T1 values were significantly elevated in both the left and right hippocampi of the SAE05 and SAE10 groups compared to the CTRL group. However, the CBF and T2 values did not exhibit significant changes across the groups. This study utilized multi-parametric MRI to evaluate functional and metabolic changes in the brain associated with SAE. The results revealed significant increases in ADC and T1 values, indicating vasogenic edema and blood–brain barrier disruption in the hippocampus, which provide crucial insights for diagnosing and developing treatments for inflammatory brain diseases.