大鼠非酒精性脂肪肝的IDEAL-IQ和MRS评价

发布时间：2018-01-09 05:35

  本文关键词：大鼠非酒精性脂肪肝的IDEAL-IQ和MRS评价　出处：《郑州大学》2016年硕士论文　论文类型：学位论文

  更多相关文章： 大鼠 非酒精性脂肪肝 磁共振成像 对比剂 MRS IDEAL-IQ

【摘要】：背景和目的随着生活方式的改变和生活水平的提高,肥胖和脂肪肝人群比例逐渐上升。非酒精性脂肪肝病(Non-Alcoholic Fatty Liver Disease,NAFLD)已成为社会的通病。脂肪肝是可逆性病变,因此,早期诊断和治疗脂肪肝是非常必要的,以防止肝脂肪变性的进一步发展。肝脏病理穿刺是诊断脂肪肝评估的金标准。然而,病理穿刺具有创伤性,所以病理穿刺不能作为筛查和长期病情监测的检查方法。因此,学者正在研究非侵入性的方法来测量脂肪含量。中华医学会2006年制定脂肪肝分级:F0(正常肝脏):脂肪变的肝细胞小于5%;F1:脂肪变的肝细胞为5%-30%,F2(轻度脂肪肝):脂肪变的肝细胞为31%-50%,F3(中度脂肪肝):脂肪变的肝细胞为51%-75%,F4(重度脂肪肝):脂肪变的肝细胞大于75%。目前能无创性测量脂肪含量的方法:超声(Ultrasound,US),计算机断层扫描(CT),MRI。超声(US)对轻度脂肪变性不敏感、主观性高,缺乏客观指标。计算机断层扫描(Computed Tomography,CT)具有辐射性,不能作为筛查和长期病情监测的检查方法。磁共振成像被认为是肝脏脂肪的非侵入性检测和定量优越的成像方法。目前用于脂肪肝评估的MRI的序列主要有:正反相位、MRS、IDEAL、IDEAL-IQ。材料与方法1.随机选取60只清洁级健康雄性SD大鼠,大鼠平均周龄5.5周龄。体重94.6±8.9 g。实验动物均由郑州大学动物实验中心提供。按照随机数字表法将大鼠分为实验组(46只)和对照组(14只),实验组高脂饮食8周、12周,对照组正常饮食8、12周。按照扫描注射对比剂的浓度,大鼠又分为:低剂量组、中等剂量组、高剂量组。2.磁共振扫描:美国GE公司Discovvery MR 750 3.0T超导高场磁共振扫描机。扫描线圈:膝关节线圈。每组大鼠均在8周、12周行磁共振。扫描的序列有:T1加权成像(T1-Weighted Imaging,T1WI)、T2加权成像(T2-weighted imaging,T2WI)、弥散加权成像(Diffusion Weighted Imaging,DWI)、波谱(Magnetic Resonance Spectroscopy,MRS)、IDEAL-IQ。然后尾静脉注射对比剂,注射对比剂后1 min、3 min行IDEAL-IQ扫描。在扫描结束后解剖去肝脏组织,进行石蜡包埋,常规切片,行HE染色。3.后处理:通过通过GE后处理工作站进行后处理:1、SAGE 7.0软件处理MRS获得脂峰下面积,通过计算得出脂肪含量;2、IDEAL-IQ进行后处理,在对应MRS扫描时定位体素块相应位置选择感兴趣区得到脂肪比值;3、对注射对比剂前后各个时间点的IDEAL-IQ相对应的位置选择感兴趣区得到脂肪比值和R2*值。4、光镜下观察病理切片,按照脂肪浸润的肝细胞数量占肝细胞总数的比例进行分级。4.实验数据运用SPSS17.0软件进行统计学分析,实验数据采用均数±标准差表示。采用简单线性回归分析MRS测得的脂肪比值(Fat Fraction,FF)(即峰下面积比值)、IDEAL-IQ测得的脂肪比值(Fat Fraction,FF)分别与大鼠脂肪肝病理程度的相关性。采用ROC分析评价MRS、IDEAL-IQ诊断非酒精性脂肪肝的最佳界点。同一剂量组各个时间点的脂肪相对含量及R2*之间的比较采用重复测量方差分,同一测量时间不同组脂肪相对含量及R2*之间的比较采用单因素方差分析,并采用L-SD检验进一步两两比较。P0.05提示差异有统计学意义。结果1.F0(脂肪变的肝细胞为5%)为Ⅰ级:9只;F1:脂肪变的肝细胞为5%-30%为Ⅱ级:11只;F2(脂肪变的肝细胞为31%-50%)为Ⅲ级:21只;F3(脂肪变的肝细胞为51%-75%)为Ⅳ级:13只;F4(脂肪变的肝细胞大于75%)为Ⅴ级:6只。2.IDEAL-IQ、MRS结果:(1).FF-IDEAL-IQⅠ级:4.63±0.60%;Ⅱ级:6.48±0.61%;Ⅲ级:9.10±1.89%;Ⅳ级:18.94±6.24%;Ⅴ级:37.67±6.17%。FF-IDEAL-IQ值与病理结果呈正相关(R=0.825,p0.01),ID IQ判定大鼠脂肪肝的阈值为7.31%。(2).FF-MRS:Ⅰ级:4.24±1.69%:Ⅱ级;7.90±1.90%;Ⅲ级:13.18+3.83%;Ⅳ级:20.71+10.15%:Ⅴ级:39.10±9.09%。FF-MRS与病理结果呈正相关(R=0.796,p0.01),MRS判定大鼠脂肪肝的阈值为10.56%。IDEAL-IQ与大鼠脂肪肝的病理程度相关性高于MRS。3.FF-IDEAL-IQ:(1).低剂量组:注射对比剂前与注射对比剂后1 min,3 min的差异均无统计学意义(F=2.280,P=0.116);(2).中等剂量组:注射对比剂前与注射对比剂后1 min,3 min的差异均无统计学意义(F=2.28,P=0.181);(3).高剂量组:注射对比剂前与注射对比剂后1 min,3 min的差异均无统计学意义(F=2.554,P=0.091)。(4).注射对比剂前:各剂量组FF的差异无统计学意义(F=0.108,P=0.898),(5).注射对比剂后1 min:各剂量组FF的差异无统计学意义(F=0.337,P=0.72)。(6).注射对比剂后3 min:各剂量组FF的差异无统计学意义(F=0.209,P=0.812)。4.R2*值:(1).低剂量组:注射对比剂前与注射对比剂后1min,3min的差异均有统计学意义(F=163.300,P=0.000);(2).中等剂量组:注射对比剂前与注射对比剂后1 min,3 min的差异均有统计学意义(F=347.457,P=0.00);(3).高剂量组:注射对比剂前与注射对比剂后1min,3 min的差异均有统计学意义(F=380.586,P=0.091);(4).注射对比剂前:各剂量组R2*值的差异无统计学意义(F=1.912,P=0.157);(5).注射对比剂后1 min:各剂量组R2*值的差异有统计学意义(F=5.236,P=0.008);(1).注射对比剂后3 min:各剂量组R2*值的差异有统计学意义(F=0.209,P=0.812)。结论1.FF-MRS与NAFL病理结果呈正相关,MRS诊断脂肪肝的阈值为10.56%。2.FF-IDEAL-IQ与NAFL病理结果呈正相关,IDEAL-IQ诊断脂肪肝的阈值为7.31%。3.DEAL IQ与大鼠脂肪肝的病理程度相关性高于MRS。4.低剂量、中等剂量、高剂量对比剂对大鼠脂肪肝模型中的FF-IDEAL-IQ值均无影响。5.IDEAL-IQ测量脂肪含量具有稳定性。
[Abstract]:Background and objective: with the change of lifestyle and the improvement of living standards, the proportion of the fatty liver and obesity increased gradually. Nonalcoholic fatty liver disease (Non-Alcoholic Fatty Liver Disease, NAFLD) has become a social problem. Fatty liver is a reversible disease, therefore, early diagnosis and treatment of fatty liver is very necessary, in order to prevent the further development of fatty degeneration of the liver. The liver pathological biopsy is the gold standard for the diagnosis of fatty liver assessment. However, pathological biopsy is traumatic, so cannot be used as a method in the screening of pathological biopsy and long-term monitoring. Therefore, scholars are studying a non-invasive method to measure the fat content. The Chinese Medical Association in 2006 to develop fatty liver: classification F0 (normal liver): less than 5% of fatty liver cell fatty degeneration of liver cells; F1: 5%-30%, F2 (mild fatty liver): fatty degeneration of liver cells of 31%-50%, F3 (moderate fat Fatty liver): fatty degeneration of liver cells of 51%-75%, F4 (severe fatty liver): fatty degeneration of liver cells than 75%. currently can be a non-invasive method of measuring fat content: ultrasound (Ultrasound, US), computed tomography (CT), MRI. ultrasound (US) is not sensitive to mild fatty degeneration of subjectivity high, the lack of objective indicators. Computed tomography (Computed Tomography, CT) with radiation, can not be used as a method in the screening and long-term monitoring. Magnetic resonance imaging is non-invasive detection and quantitative imaging of fatty liver. The superior method currently used to evaluate the MRI sequence of fatty liver are: positive and negative MRS, IDEAL, IDEAL-IQ. phase, materials and methods of 1. randomly selected 60 clean grade healthy male SD rats, rats 5.5 weeks of age. The average age of 94.6 + 8.9 g. body weight of experimental animal by the Zhengzhou University animal experimental center. According to the random number table will be The rats were randomly divided into experimental group (46 rats) and control group (14 rats) and experimental group with high fat diet for 8 weeks, 12 weeks, the control group with normal diet 8,12 weeks. According to the concentration of scan contrast injection, rats were divided into low dose group, medium dose group, high dose group of.2. magnetic resonance scanning American GE company Discovvery MR 750 3.0T high field superconducting magnetic resonance scanner. Scanning coil: knee coil. The rats were 8 weeks, 12 weeks. Magnetic resonance scanning sequence: T1 weighted imaging (T1-Weighted Imaging, T1WI), T2 (T2-weighted imaging, T2WI weighted imaging, diffusion weighted) imaging (Diffusion Weighted Imaging, DWI (Magnetic), Resonance Spectroscopy, MRS spectrum, IDEAL-IQ.) and intravenous injection of contrast agent, after contrast agent injection 1 min, 3 min IDEAL-IQ scanning. After scanning the anatomy to liver tissue were embedded in paraffin, paraffin sections, stained with HE.3. postprocessing by: by GE Postprocessing workstation for postprocessing: 1, SAGE 7 software MRS lipid peak area, obtained by calculating the fat content; 2, IDEAL-IQ postprocessing, positioning in the corresponding MRS scanning voxel block corresponding to the position selection of region of interest are fat ratio; 3, to get fat injection ratio and R2* value of.4 the corresponding ratio of agent before and after each time point IDEAL-IQ to choose the location of region of interest, the pathological observation under light microscope, grading.4. experimental data using SPSS17.0 statistical analysis software according to the fatty infiltration of the liver cells accounted for the proportion of the total number of liver cells, the experimental data expressed by the mean and standard deviation. The regression analysis of fat the ratio of MRS measured by simple linear (Fat Fraction, FF) (i.e. peak area ratio), the ratio of fat measured by IDEAL-IQ (Fat Fraction, FF) were correlated with the pathological degree of fatty liver in rats. Using ROC analysis 璇勪环MRS,IDEAL-IQ璇婃柇闈為厭绮炬，

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