正常成人肾脏水分子扩散加权成像的研究

目的定量研究正常成人肾脏水分子扩散的特性并探讨其发生机制。方法用平面回波成像(EPI)技术对63例健康正常人的腹部实质器官(肝、脾、肾及胰腺)分别行磁共振扩散加权成像(DW I)并测量各自的表观扩散系数(ADC)。结果肾脏髓质的ADC值最高,肾脏的ADC值(包括皮质及髓质)明显高于腹部其它实质器官的ADC值(P<0.05);肾髓质的ADC值在不同扩散敏感梯度方向上存在统计学差异(P<0.05)。结论肾脏组织内水分子扩散表现为各向异性,其高ADC值与肾脏的含水量、水分子转运及血流灌注相关。     

表观扩散系数与T2值诊断肝脏局灶性小病变的比较

目的比较表观扩散系数(ADC)及T2值在区分肝脏局灶性小病变性质方面的价值.方法62例(84个病灶)肝脏局灶性占位小病变患者(其中包括原发性肝细胞癌19例23个病灶,肝转移瘤11例18个病灶,肝海绵状血管瘤24例32个病灶,肝囊肿8例11个病灶)分别行磁共振扩散加权成像(DWI)和快速自旋回波(SE)T2WI,测量、分析、对比各病变的ADC值及T2值.所有病例均经手术病理或CT、B超临床确诊.结果肝癌、肝转移瘤、肝血管瘤及肝囊肿的平均ADC值分别为(1.35±0.18)×10-3mm2/s、(1.41±0.12)x10-3mm2/s、(2 39±0.21)×10-3mm2/s、(3.44±0.27)×10-3mm2/s,肝脏恶性病变的ADC值明显低于良性病变(P＜0.01),其诊断正确率为94.0%;肝脏恶性病变的T2值也低于良性病变(P＜0.05),但两者数值重叠较多,其诊断正确率为78.6%.T2值诊断正确率明显低于ADC值(P＜0.05).结论ADC值在肝脏局灶性小病变定性诊断方面优于T2值,更具临床价值.     

APP/PS1转基因阿尔茨海默病小鼠的MR波谱定量分析

Objective To explore changes of metabolites in APP/ PS1 double transgenie mice of Alzbeimer disease (AD) by 1H-MR spectroscopy (1H-MRS) and the application value of in early diagnosis of AD.Methods 1H-MRS was performed in 35 APP/PS1 transgenie mice of AD ( study group) and 20 wild type mice ( control group) at age of 3, 6 and 9 months using a 7.0 T MR system.Sub-peak areas of N-acetyl aspartate (NAA), myo-inositol (mI) and creatine (Cr) in the cerebral cortex and hippocampus were measured, and the NAA/Cr and mI/Cr ratios were calculated.The changes in pathology between the two groups were compared.Using the lower limit of 95% confidence interval (CI) of the ml/Cr ratio and the upper limit of 95% CI of the NAA/Cr ratio of AD mice as the threshold, their influences on sensitivity,specificity and accuracy of various age groups of AD animals were compared.Comparison of the 1H-MRS indexes between study mice and wild type mice at each time point were conducted by a two-sample t test.Results The mean mI/Cr ratios of AD mice were 0.68± 0.03, 0.72± 0.04, and 0.77 ± 0.04 respectively at 3, 6 and 9 months of age; while they were 0.63 ± 0.04, 0.64 ± 0.03, and 0.64 ± 0.04 respoetively in control group, the difference was significant ( t = 2.814, 5.146, 14.437, P < 0.01 ).Compared with the control group, the mI/Cr ratio of the 3-month-old AD mice of the study group was significantly increased,and histological examination showed proliferation and activation of neuroglial cells in the cerebral cortex and hippoeampus.The mean NAA/Cr ratio were 1.17 ±0.08, 1.04 ±0.05, and 0.90 ±0.05 respectively at 3,6 and 9 months of age in study group, while they were 1.18 ±0.07, 1.16 ±0.07, and 1.18 ±0.08respectively in control group.There were no significant difference ( t = 0.752, P > 0.05 ) between the study group and control group at 3 months of age, and the NAA/Cr ratio decreased significantly only at 6 and 9 months of age ( t = - 8.514, - 5.646, P < 0.01 ).The immunohistochemical exam demonstrated the appearance of Aβ plaque.According to threshold of mI/Cr, the sensitivity of AD mice of 3, 6 and 9 months of age was 80% (28/35), 84% ( 26/31 ) and 85% ( 23/27 ), and the specificity was 85% ( 17/20 ),94% (17/18) and 100% ( 16/16), and the accuracy was 82% (45/55), 88% (43/49) and 91% (39/43),respectively.For NAA/Cr, the sensitivity of AD mice of 6 and 9 months of age was 84% (26/31) and 89% (24/27), and the specificity was 89% (16/18) and 100% (16/16), and the accuracy was 86% (42/49) and 93% (40/43), respectively.Conclusions NAA and mI are the most sensitive and specific markers for early assessment of AD, and change of mI is earlier than that of NAA.Quantitative analysis of mI may provide important clues for early diagnosis of AD.     

TNF-α和IL-6在慢性心力衰竭中的变化及意义

目的 观察肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)在慢性心力衰竭(CHF)患者中的变化及其临床意义.方法 用放免法测定49例基础疾病为缺血性心脏病、扩张型心肌病及高血压性心脏病的CHF患者和30例健康体查者的血清TNF-α和IL-6浓度,并进行比较分析.结果 CHF患者血清TNF-α和IL-6水平明显高于正常对照组(P＜0.01),并与左室射血分数(LVEF)呈显著负相关(P＜0.01).且心衰程度越重,TNF-α和IL-6升高越明显.结论 CHF时血清TNF-α和IL-6浓度明显升高,并与CHF严重程度相关.TNF-α和IL-6可作为CHF患者临床评价的参考指标.     

多模态MRI对致密型乳腺中乳腺癌的诊断价值

目的：探讨多模态 MRI 上致密型乳腺中乳腺癌的影像学特征。方法收集行乳腺 X 线及 MRI 检查的120例乳腺癌病例,均为单病灶,且经手术病理证实,根据乳腺 X 线摄影 BI-RADS 分类的标准,将乳腺分成致密型(68例)和非致密型(52例)2组,对照研究2种乳腺类型中乳腺癌的 MRI 形态学特征、表观扩散系数(ADC)值(b=1000 s/mm2)、时间-信号强度曲线(TIC)间的差异。采用 SPSS16.0统计软件,P 值<0.05为差异有统计学意义。结果致密型与非致密型2组乳腺中病灶边缘毛刺分别为64.7%(44/68)、30.8%(16/52),其差异有统计学意义(P =0.000);2组乳腺癌直径分别为(1.83±0.98)cm、(1.40±0.46)cm,其差异有统计学意义(P =0.005);2组病灶呈非肿块样强化的分别为72.1%(49/68)、34.6%(18/52),其差异有统计学意义(P =0.000);2组病灶的ADC 值(b=1000 s/mm2)分别为(0.89±0.12)×10-3 mm2/s,(0.95±0.10)×10-3 mm2/s,其差异有统计学意义(P =0.016)。结论相对非致密型乳腺,致密型乳腺中的乳腺癌在多模态 MRI 表现上具有一定的特征。     

双能量减影骨组织像与DR常规像在肋骨骨折诊断中的对比观察

目的:探讨双能量减影骨组织像与DR常规像在肋骨骨折诊断中的应用价值。方法:对48名共计192根临床疑诊肋骨骨折的患者,采用双能量减影法摄胸部正斜位片,获得DR常规像和骨组织像,两组医师分别作出诊断,比较DR常规像、骨组织像诊断的结果。结果:DR常规像、骨组织像对肋骨凹陷状骨折的检出率分别为26.92%、23.08%;对裂隙状骨折的检出率分别为11.11%、66.67%;对错位状骨折的检出率均为100%。DR常规像诊断肋骨骨折的敏感性76.72%,特异性100%,阳性预测值100%,阴性预测值73.79%,准确性85.94%;骨组织像则分别80.17%、97.37%、97.89%、76.29%和86.98%,两组的敏感性和准确性无显著差异(P>0.05)。结论:双能量减影骨组织像有利于细小裂隙状骨折的显示;DR常规像观察凹陷状骨折与骨组织像效果相同或更好,两者对肋骨骨折的诊断能力相当。     

多层螺旋CT多平面重建在急性阑尾炎诊断中的应用

目的探讨多层螺旋CT（MSCT）多平面重建（MPR）技术在急性阑尾炎诊断中的应用价值。方法对42例疑诊急性阑尾炎患者行全腹部MSCT扫描,回盲部薄扫,经工作站后处理获得回盲部MPR像。比较仅轴位像、轴位结合MPR像两种方法的诊断结果。结果对照手术病理,仅阅读轴位像诊断急性阑尾炎的敏感性82.86%,特异性28.57%,阳性预测值85.29%,阴性预测值25%,准确性73.81%;轴位结合MPR像诊断的敏感性94.23%,特异性57.14%,阳性预测值91.67%,阴性预测值66.67%,准确性88.10%。结论 MSCT应用MPR技术能够将阑尾基部、回肠末端及盲肠显示在同一平面图像上,对阑尾空间关系的把握和细节的观察更具优势,提高了临床疑诊急性阑尾炎患者的术前诊断能力。     

连续低剂量X线照射对孕鼠子代海马CA1区锥体细胞增殖的影响

目的 探讨孕期连续受低剂量X线照射对子代Sprague-Dawley大鼠海马回1区(CA1)锥体细胞增殖的影响,并揭示造成影响的相关机制.方法 确定受孕SD大鼠25只,抽签法随机分为4个实验组(H组、M组、L1组及L2组,分别接受0.09 mGy/d、0.06 mGy/d、0.03 mGy/d、0.015 mGy/d剂量的X线照射,照射18 d,无间隔)及对照组(C组,接受假照射),每组5只,仔鼠分组同孕鼠.通过HE染色、Envision免疫组织化学法及图像处理系统对大鼠海马CA1区锥体细胞形态学进行观测(锥体细胞层次宽度及细胞密度变化)及胞质内细胞外信号反应激酶(ERK)1和(或)ERK2蛋白表达的检测.结果 (1)孕期连续受到低剂量X线照射可以促进子代海马CA1区锥体层次宽度的增加,H组、M组、L1组及L2组的锥体层次宽度(像素)分别为129.620±38.491、116.217±1.161、118.343±20.916、122.066±13.036,高于C组(89.797±3.919),差异有统计学意义(F值分别为8.475、33.42、14.395、44.955;P值分别为0.002、0.048、0.030、0.012);但H组锥体细胞排列稀疏、松散,单位面积锥体细胞密度低于其他各组(0.1249±0.0246),差异有统计学意义(F值为4.466,P值为0.017).(2)L1组、L2组大鼠海马CA1区ERK1和(或)ERK2阳性细胞平均吸光度值(A值)(0.3082±0.0240、0.3125±0.0412)高于C组(0.2457±0.0694),差异有统计学意义(F值分别为4.561、4.103,P值分别为0.044、0.035);M组及H组阳性细胞A值分别为0.2287±0.0228和0.2326±0.0331,与对照组相比较差异无统计学意义(F值分别为0.326、0.174,P值分别为0.888、0.951).结论 孕期连续受到低剂量X线照射可以促进子代海马CA1区锥体细胞发生增殖性改变,这一作用可能是通过促进细胞内ERK1和(或)ERK2蛋白表达增加来实现的,达到一定剂量时(0.09 mGy/d)呈现出增殖过度的表现.     

APP/PS1转基因AD小鼠磁共振波谱及行为学的对照观察

目的 探讨氢质子磁共振波谱(1H-MRS)成像对APP/PS1转基因AD小鼠代谢变化的显示及其早期诊断价值.方法 35只APP/PS1AD小鼠(实验组)和20只同源野生型小鼠(对照组)在6、9月龄时接受Morris水迷宫测试及1H-MRS成像.1H-MRS测量小鼠大脑海马区N-乙酰天门冬氨酸(NAA)、肌醇(mI)和肌酸(Cr)的峰下面积,计算NAA/Cr和mI/Cr比值并进行两样本均数t检验.结果 与对照组比较, 实验组小鼠6月龄时mI/Cr比值明显升高(t=2.904,P＜0.05),NAA/Cr比值明显降低(t=-7.535,P＜0.05).免疫组化检查显示海马区出现Aβ沉积斑块,周围包绕活化的胶质细胞;而行为学差异在9月龄时才有统计学意义(P＜0.05),表现为小鼠学习和记忆方面的损害.结论 1H-MRS是早期评价AD的高敏感性、高特异性的方法,mI、NAA的变化早于行为学改变.