Progressive Metabolic and Structural Cerebral Perturbations After Traumatic Brain Injury: An In Vivo Imaging Study in the Rat

Journal of Nuclear Medicine

Rod J. Hicks¹  Viviane Bouilleret¹  Damian E. Myers¹  Nigel C. Jones¹  Ying R. Liu¹  David Binns¹  Amelia Koe¹  Terence J. O'Brien¹  R. Edward Hogan¹  Marie-Claude Gregoire¹  Lisa Cardamone¹  John P. Williams¹ 

关键词: traumatic brain injury;    rat;    ¹⁸F-FDG PET;    MRI;    anxiety;   

DOI  :  10.2967/jnumed.110.078626

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

Traumatic brain injury (TBI) has a high incidence of long-term neurologic and neuropsychiatric morbidity. Metabolic and structural changes in rat brains were assessed after TBI using serial 18F-FDG PET and 3-dimensional MRI in vivo. Methods: Rats underwent lateral fluid percussion injury (FPI; n = 16) or a sham procedure (n = 11). PET and MR images were acquired at 1 wk and at 1, 3, and 6 mo after injury. Morphologic changes were assessed using MRI-based regions of interest, and hippocampal shape changes were assessed with large-deformation high-dimensional mapping. Metabolic changes were assessed using region-of-interest analysis and statistical parametric mapping with the flexible factorial analysis. Anxiety-like behavior and learning were assessed at 1, 3, and 6 mo after injury. Results: PET analyses showed widespread hypometabolism in injured rats, in particular involving the ipsilateral cortex, hippocampus, and amygdalae, present at 1 wk after FPI, most prominent at 1 mo, and then decreasing. Compared with the sham group, rats in the FPI group had decreased structural volume which progressively increased over 3–6 mo, occurring in the ipsilateral cortex, hippocampus, and ventricles after FPI (P < 0.05). Large-deformation high-dimensional mapping showed evolving hippocampal shape changes across the 6 mo after FPI. Injured rats displayed increased anxiety-like behavior (P < 0.05), but there were no direct correlations between the severity of the behavior abnormalities and functional or structural imaging changes. Conclusion: In selected brain structures, FPI induces early hypometabolism and delayed progressive atrophic changes that are dynamic and continue to evolve for months. These findings have implications for the understanding of the pathophysiology and evolution of long-term neurologic morbidity following TBI, and indicate an extended window for targeted neuroprotective interventions.

【 授权许可】

Unknown