家犬脑梗死ADC值、T2信号强度的演变规律及病理对照研究  

THE CONTROLLING STUDY OF ADC,T2 SIGNAL INTENSITY IN BRAIN MRI AND BRAIN MORPHOLOGIC CHANGES IN STROKE DOGS

作　　者：汪国石[1] 武柏林[1] 刘怀军[1] 王立新[1] 玉鉴[1] 黄渤源[1] 

机构地区：[1]河北医科大学第二医院医学影像科,河北石家庄050000

出　　处：《河北医科大学学报》2008年第5期701-704,806,共5页Journal of Hebei Medical University

基　　金：河北省卫生厅资助项目(01010)

摘　　要：目的了解中风后MR表观弥漫系数（appearance diffuse coefficient,ADC）值、T2信号强度的变化过程,并与形态学检查和免疫组织化学染色结果相对照。方法18只健康成年家犬,制成脑梗死动物模型。依处死时间不同（次日、3d、1周和2周）随机分成4组。手术结束后多时点MR扫描,序列为T1WI、T2WI、3D-TOFMRA、DWI。以MR图像为依据选择病变部位分别进行HE染色,免疫组织化学染色,并进行光镜、电镜观察。测量ADC值、T2信号强度,根据CD34免疫组织化学染色结果计数毛细血管数,方差分析法分析不同时间点结果的差异,并进行相关性分析。结果术后1h DWI可见梗死区明显高信号,且随时间的延长强度逐渐增高。ADC值术后3～4h下降到（5.61±1.39）mm^2/s,相对于对侧半球的（9.85±2.04）mm^2/s下降了大约43%,2周时达（9.83±1.11）mm^2/s,仍然略低于正常。T2信号由24h的（4040.00±468.66）升高到2周时的（4806.80±739.52）。ADCr、T2r的变化与微血管计数变化存在显著正相关关系（r=0.679、0.721,P〈0.01）。形态学及电镜观察可见相应不同程度的缺血改变。结论脑梗死后ADC值变化呈先降后升规律,T2信号强度短期内持续升高,与MVC的变化存在正相关关系。Objective To investigate the evolution of appearance diffuse coefficient（ADC）, T2 signal intensity after infarction in canine and compare these data with morphologic and immunohistochemistric changes. Methods Eighteen adult dogs were divided into four groups according to the different time of sacrifice（1 day, 3 day, 1 week, 2 week） after the focal cerebral ischemic infarction model was produced. MR scan-TlWI. T2WI, FLAIR, 3DTOF-MRA. DWI was conducted at different time after stroke. At various survival time. dogs were sacrificed and specimens were selected based on the abnormal manifestations on MR images and stained with HE or immunohistochemistry, examined by light microscopy or electron microscopy. The microbloodvessel count （MVC）. Lesion-to-normal ussue signal intensity rano on ADC maps （ADCr） and on T2-weighted images （T2r） were calculated and analyzed by SPSS 10.0. Results The signal intensity of infracted tissue on DWI images was markedly higher than that of normal brain tissue at one hour after stroke, and becaming higher and higher at the following three scan time. ADC value declined to （5.61 ± 1.39） mm^2 / s 3 ～ 4 hours after stroke, which was only 43% of the other hemiphere（9.85±2.04）mm^2/s. It became （9.83±1.11）mm^2/s at two weeks after stroke,also lower than normal leval. Data initial decline during acute period and subsequent also showed a trend in ADCr evolution.an increase in the following several weeks. Correlation analysis revealed that there was significant positive correlation relationship between ADCr,T2r and MVC（ r =0. 679 and 0. 721, P 〈0.01）. Conclusion The ADC declined to some level and then increased, the T2 value increased and had positive correlation relationship with MVC after stroke.

关 键 词：磁共振成像 脑梗塞 疾病模型 动物 狗 

分 类 号：R445.2[医药卫生—影像医学与核医学]