摘要
目的研究尾静脉给药锰离子增强MRI（MEMRI）显示大鼠脑皮层结构的作用，并比较有无血脑屏障开放对皮层结构显示的影响。方法15只sD大鼠，采用随机排列表方法随机分为3组，每组5只。A组，右侧颈内动脉注入30％甘露醇开放血脑屏障后尾静脉注1130mmoL／L MnCl2生理盐水溶液，12h后行MRI；B组，右侧颈内动脉注入生理盐水后尾静脉注100mmol／LMnCl2溶液，12h后行MRI；C组作为正常对照，不做任何处理直接进行MRI。成像采用7．0Tmicro—MR扫描仪。采用Paravision4．0软件测量各组大脑皮层、小脑皮层、嗅球皮层、海马、垂体等ROI的信噪比，各组间信噪比比较采用单因素方差分析，两侧大脑半球间信噪比比较采用配对t检验。结果MEMRI能清楚显示大鼠脑灰、白质结构及皮层的条带状结构，能显示感觉运动区的解剖边界；室周结构如海马、齿状回、缰联合、嗅球等结构能清楚显示。Mn2＋增强后鼠脑右侧大脑皮层、两侧小脑皮层、海马和垂体信噪比升高，A、B、C组SNR值；大脑皮层右侧分别为35．24±7．0、30，1±2．4、26．6±2．8．F=4．36，P=0．038；左侧小脑皮层27．1±5．2、29．4±3．8、19．4±4．5，F=6．66，P=0．011；右侧小脑皮层27．8±3．8、28．5±4．2、20．4±4．8，F=5．84，P=0．017；左侧海马34．5±4．9、38．1±5．3、24．5±3．6，F=11．38，P=0．002；右侧海马35．3±5．5、37．6±4．7、25．6±3．0，F=9．93，P=0．003；垂体39．5±3．8、52．6±9．1、26．2±4．2，F=22．80，P=0．001。其余部位SNR差异无统计学意义（P〉0．05）。B组两侧皮层强化比较一致。A组两侧皮层不对称强化，开放血脑屏障侧大脑皮层强化更明显，条带状结构显示较模糊，但是两侧半球各部位强化差别无统计学差异（P〉0．05）。结论尾静脉给药MEMRI能特异性显示大鼠脑皮质分层结构及感觉运动皮层区的解剖边界。高浓度甘露醇能有效开放血脑屏障，并对脑皮层结构显示产生影响。开放与不开放血脑屏障锰离子MEMRI各具特征，可以根据实际需要进行选择。
Objective To study the role of manganese-enhanced MRI（MEMRI） in the depiction of cortical architecture of rat brain after systemic administration of Mn2＋ througb caudal vein and compare the effects of normal or opened blood-brain barrier on the manganese-enhanced MRI. Methods Fifteen SD rats were randomly divided into three groups according to ranked list of random. Blood-brain barrier was opened in short time by the injection of 30% mannitol via the right internal carotid artery in group A, then 100 mmol/L MnCl2 physiologic saline solution was delivered through vena caudalis, and MRI was performed 12 hours later. In group B, 100 mmol/L MnCl2 physiologic saline solutions was administrated through vena caudalis, following normal saline injection into the right internal carotid artery, and MRI was performed 12 hours later. The group C served as normal control group. All images were acquired with a 7.0 T micro- MR scanner. Signal-to-noise ratios （SNR） in regions of interest were measured by Paravision 4. 0 and the differences of three groups were compared by using one-way ANOVA. The differences of SNR on both sides of hemispheres were compared by using paired t test. Results MEMRI could show the gray matter and white matter of rat brain and the anatomy borders between somatosensory cortex and motor cortex clearly. Periventricular structures such as hippocampus, dentate gyrus, habenula united, and olfactory bulb could also be showed clearly. Symmetrical enhancement on both sides of the cortex and banded structures was shown clearly in group B. The SNR increased and the differences were significant in right cerebral cortex, both sides of cerebellar cortex, hippocampus and pituitary among three groups （ right cerebral cortex 35.2 ± 7.0,30. 1±2.4,26.6 ±2.8,F =4. 36,P = 0. 038;left cerebellar cortex 27. 1 ±5.2,29.4± 3.8,19.4±4. 5 ,F =6. 66 ,P =0. 011 ;right cerebellar cortex 27.8 ±3.8,28.5 ±4.2,20. 4 ±4. 8 ,F =5.84,P =0. 017; left hippocampus 34. 5 ±4. 9,38. 1 ±5.3,24. 5 ±3.6,F = 11.38 ,P=0. 002 ;right hippocampus 35.3 ±5. 5, 37.6±4.7,25.6±3.0,F=9.93,P=0. 003 ; pituitary 39.5±3.8,52.6 ±9.1,26.2±4.2,F=22.80, P =0. 001） after systemic administration of Mn2＋. Asymmetric enhancement on two sides of cortex was shown in group A. The mannitol-infused side was enhanced obviously but displayed blurring banded structures. However,the SNR differences of both sides of hemispheres in group A and B were not significant （ P 〉 0. 05 ）. Conclusions After systemic administration of MnCI2 through vena caudalis, MEMRI could map the laminar architectures and the anatomy border of functional zone of somatosensory cortex specifically. High concentration of mannitol could open blood brain barrier（BBB） effectively and have distinct impacts on the architectures displayed in MEMRI. Opening or maintaining BBB in MEMRI had respective characteristics, and it should be selected according to practical needs.
出处
《中华放射学杂志》
CAS
CSCD
北大核心
2010年第2期202-206,共5页
Chinese Journal of Radiology
基金
国家自然科学基金资助项目（30770625）志谢东南大学临床医学院张小江、潘晶晶同学在动物模型制作中给予帮助
关键词
大脑皮质
锰
磁共振成像
血脑屏障
Cerebral cortex
Manganese
Magnetic resonance imaging
Blood-brain barrier
