大鼠脑外伤模型的磁共振波谱研究

Magnetic resonance spectroscopy of traumatic brain in SD rats model

目的通过SD大鼠脑外伤模型,探讨磁共振波谱对脑外伤的早期诊断价值及前景。方法雄性大鼠40只,自由落体复制创伤性脑损伤的动物模型,分别进行损伤前及损伤后4h、8h、24h、48h行MRS检查,观察NAA/Cr、Cho/Cr的变化,并与病理对照。结果打击后4h即可见到创伤性脑损伤的病理表现,MRS示NAA/Cr4h显著下降,8h逐渐恢复上升,然而24～48h之间变化无显著差异;而Cho/Cr损伤前后变化无显著差异。结论MRS能无创性定量监测脑外伤脑组织生化代谢改变,MRS有望成为早期诊断、预后及疗效提供参考指标。

Objective To assess the value and prospect of magnetic resonance spectroscopy（MRS） in early diagnosis of traumatic brain with traumatic brain model in SD rats. Methods Traumatic brain modal was established in 40 male SD rats utilizing a weigh-drop device, and MRS was performed before trauma and 4,8,24 and 48 hours after trauma. The ratio of N-acetylaspartate/creatine （NAA/Cr） and choline/creatine （Cho/Cr） were calculated and compared with pathological findings respectively. Results Axonal changes were confirmed in microscopic study 4 hours after injury. The ratio of NAA/Cr decreased distinctly at 4 hours after trauma, followed by a steadily recover at 8 hours, and no significant change from 24h to 48h. There was no significant change in the ratio of Cho/Cr before and after trauma. Contusion MRS can be used to monitor the metabolic changes of brain non-invasively. MRS could play a positive role in early diagnosis, prognosis and follow-up of traumatic brain.