ABSTRACT
Objective To investigate proton magnetic resonance spectroscopy(~1H-MRS)findings and value on dog's brain contusion and laceration.Methods Models of focal brain contusion and laceration in 10 dogs were established through hitting on the right frontal-parietal lobe with a freely drop of 200g weight at 1.3 m height.Serial examinations(1 h,24 h,72 h,5 day,8 day and 14 day after trauma)were performed with conventional MRI and ~1H-MRS.NAA/Cr,Cho/Cr and NAA/Cho rates were analyzed with GE system 1.5 T scanner and relative software.After examination,all dogs were executed to death. Pathological study was performed at local brain contusion.Results 1 h and 24 h-post trauma,NAA/Cr、Cho/Cr、NAA/Cho were significantly reduced(NAA/Cr 0.843?0.214,0.862?0.204,contralateral ones 1.069?0.284,1.048?0.232,t=-7.227,-6.718,Cho/Cr 1.181?0.224,1.243?0.134,contralateral 1.415?0.305,1.455?0.159,t=-4.332,-4.489,NAA/Cho 0.701?0.147,0.536?0.136, contralateral 0.832?0.245,0.613?0.165,t=-2.652,-2.665.P＜0.05).Microscopy showed focal petechial hemorrhage and necrosis,neuron loss,neuraxonal swelling and small glial cell slightly hyperplasia.Five day post trauma,Cho/Cr was significantly elevated in comparison with contralateral ones (1.517?0.197,contralateral 1.387?0.214,t=3.758.P＜0.05).Pathologically,inflammatory was obvious,peri-angiitis,granula tissue and fibrosis were seen.8—14 day later,NAA/Cr was not significantly reduced(0.895?0.105,0.875?0.153,contralateral 0.989?0.169,0.990?0.173,t=-2.909, -2.471.P＞0.05),Cho/Cr was significantly increased(1.457?0.168,1.572?0.374,contralaterl 1.334?0.174,1.366?0.352,t=7.312,3.201.P＜0.05)Inflammatory and gila1 hyperplasia was more significant,granuloma were seen.Lipid and Lac peak were not seen at all stages.Conclusion MRS could be a methods to monitor neuron injury and repair,and dynamically to detect the metabolic changes of brain contusion and laceration,reflecting injury severity and provide theory data for early treatment and predicting long-term outcome after trauma.