猴脑选择性超深低温断血流复苏的质子MR波谱研究

The study of 1H-MRS on monkey of resuscitation after cerebral selection ultra-profound hypothermic blood flow occlusion

目的探讨MR氢质子波谱(protion magnetic resonance spectroscopy,1HMRS)在猴脑选择性超深低温断血流复苏前后的表现,研究脑选择性超深低温断血流对猴脑组织及细胞生化代谢的影响,以进一步探明脑选择性超深低温技术的有效性和安全性。方法恒河猴4只。常温下临时阻断双侧颈外静脉、左侧颈内动脉和颈内静脉10min后,通过1侧颈内动脉冷灌注,同侧颈内静脉回流,阻断其他颈部血管,建立选择性脑局部体外循环通路,降低脑温至(15.1±0.9)℃,60min后恢复脑血流,实验动物自然复苏。于手术前,恢复脑血流后4、24、72h、21d分别行常规MR检查[扫描序列包括T1WI、T2WI、快速水抑制反转恢复序列(FLAIR)]、扩散加权成像(DWI)及脑双侧额顶叶近皮质区、双侧基底节区的1HMRS检查。1HMRS采集感兴趣区N乙酰天门冬氨酸(NAA)、含胆碱复合物(Cho)、肌酸和磷酸肌酸(creatine,phosphocreatine;Cr,PCr)4种微量代谢物的共振峰及曲线下面积,并对术前及术后不同时点的NAA/(Cr+PCr)、Cho/(Cr+PCr)的曲线下面积进行NAA、Cho的相对浓度分析。结果常规MR扫描(T1WI、T2WI、FLAIR)及DWI提示脑实质内无异常信号改变;各部位手术前后不同时间NAA/(Cr+PCr)比值比较显示:右基底节区F值=0.356,P值=0.835;左基底节区F值=1.405,P值=0.291;右额顶区F值=2.085,P值=0.460;左额顶区F值=0.606,P值=0.666。各部位手术前后不同时间Cho/(Cr+PCr)比值比较显示:右基底节区F值=0.680,P值=0.620;左基底节区F值=0.680,P值=0.620;右额顶区F值=0.065,P值=0.991;左额顶区F值=1.403,P值=0.291。双侧基底节区及双侧额顶叶近皮质区NAA/(Cr+PCr)、Cho/(Cr+PCr)在术前及术后不同时点差异均无统计学意义(P>0.05)。结论1HMRS的定量研究从脑组织生化代谢角度提示脑选择性超深低温可明显提高脑对缺血缺氧的耐受性,其结果有助于进一步认识脑选择性超深低温断血流技术的有效性和安全性。

Objective To investigate the appearance and feature of ^1H/protion magnetic resonance spectroscopy（^1H-MRS） on resuscitation after cerebral selective ultra-profound hypothermic and blood flow occlusion. To study effects of cerebral biochemical metabolism after cerebral selective ultra-profound hypothermia and blood flow occlusion and to explore the validity and feasibility of it. Methods Bilateral carotid arteries and jugular veins were clipped about 10 minutes before perfusion. Then selective cerebral circulation was established by perfusion of cooling lingers liquid through right internal carotid artery and flow out of left jugular vein with clip of other carotid arteries and jugular veins. Brain temperature reached （ 15.1 ± 0.9） ℃ , while the body temperature maintained （32.50 ± 0.58） ℃. Cerebral blood recovered after 60 minutes of cerebral ischemia and monkey came back. The cerebral MAI and DWI as well as ^1H-MRS were examined 4,24,72 h,21 days before and after cerebral selective ultro-profound hypothermia and blood flow occlusion. The peak of N-acetyl-aspartate （NAA） , Choline （Cho） , creatine and phosphocreatine （ Cr, PCr） of VOL were compare with those of control group in different time. Results MRI T1WI, MRI T2WI and DWI is normal in different time in different region ; there was not a significant difference in the ratio of NAA/ （Cr＋ PCr）, Cho/（Cr ＋ PCr） in ROI in different time in the different region in the light of statistical analysis（ P 〉 0.05 ）. Conclusion The light of cerebral biochemical metabolism, selective ultra-profound hypothermia is safety and may provide effective protective effects and safety during cerebral ischemia.