螺旋CT灌注成像在肾上腺增生的诊断价值

目的: 研究多层螺旋CT灌注成像在肾上腺增生的诊断价值。方法: 对23例正常肾上腺和18例经临床证实的肾上腺增生进行16层螺旋CT灌注成像研究,利用CT灌注软件计算灌注参数,包括相对血流量(RBF)、平均通过时间(MTT)和表面通透性(PS),参数间比较采用t检验。结果: 正常肾上腺的RBF、MTT和PS分别为0.63±0.22mL/100g/min、70.65±12.31s和0.72±0.13mL/100g/min,肾上腺增生RBF、MTT和PS分别为0.45±0.19mL/100g/min、118.39±19.98s和0.49±0.21mL/100g/min。正常肾上腺的RBF、PS均大于肾上腺增生,肾上腺增生的MTT大于正常肾上腺,其差异有统计学意义(t值分别为15.91、20.03和9.96,P<0.05)。结论: 肾上腺多层螺旋CT灌注成像是可行的肾上腺功能成像检查,它反映了肾上腺微循环的血流灌注状况,为肾上腺增生的诊断提供有用的信息。     

胰腺CT灌注成像的研究进展

摘要：作为新兴的功能学成像方法,胰腺CT灌注成像可以定量测量血容量、血流量、毛细血管表面通透性和平均通过时间等灌注参数,进而反映胰腺局部组织病理变化而引起的血流灌注改变。目前胰腺CT灌注成像的研究主要集中在正常胰腺组织、胰腺癌、胰腺炎及胰腺神经内分泌肿瘤等方面,部分灌注参数的研究结果在不同研究中差异较大。但随着多排螺旋CT软硬件技术的发展,胰腺CT灌注成像研究有加速趋势,全面临床应用将成为可能。关键词：胰腺疾病;体层摄影术;x线计算机;CT灌注成像文章编号：l004-4140（2014）Ol-0183-09中图分类号：R814．42;R445．3文献标志码：A     

成人型烟雾病的CT灌注研究

目的:探讨多层螺旋CT灌注检查在成人型烟雾病(MMD)患者诊治中的应用价值。方法:收集经DSA证实的MMD患者15例,所有患者均接受CT灌注检查。测量病变区额叶、颞叶及基底节区域脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT),并与10例对照组的脑灌注参数进行比较。结果:15例患者均发现异常灌注脑区,与对照组比较,患者组额叶、颞叶CBF、CBV降低、MTT延长,差异具有显著统计学意义(P<0.05)。基底节区CBF减低,MTT延迟,而CBV与对照组无明显差别。结论:CT灌注成像不仅有助于判断成人型MMD脑缺血的部位及程度,而且能为临床医生选择适当的手术时机和最佳术式提供客观依据。     

正常胰腺64层螺旋CT灌注成像的特征研究

应用多层螺旋CT对正常胰腺的CT灌注特点进行分析,研究正常胰腺灌注参数与年龄、性别的关系及正常胰腺不同部位灌注参数变化特征。30例胰腺正常者行腹部CT检查,其中3例健康志愿者,27例因其他疾病行腹部CT检查病人。按年龄分为3组:年龄小于40岁组、41岁~60岁组、大于61岁组。采用德国Siemens somatom Sensation64层螺旋CT进行胰腺动态增强扫描,层厚2.4mm,管电压100kV,管电流120mA。对比剂欧乃派克(300mgI/mL)100mL,Irich missouri高压自动注射器自动注射,注射速率为5mL/s,总量50mL。延迟6s开始扫描,共扫描30s。利用Siemens somatom Sensation型64层螺旋CT自带软件PCT进行处理得到灌注参数:F_b(血流量)、V_b(血容量)、T_tp(峰值时间)、P_S(表面通透性)等。正常胰腺血流灌注平均F_b、V_b、T_tp、P_S分别为(133.55±25.70)(mL/100mL/min)、(193.78±27.01)(mL/L)、(142.41±13.95)(0.1s)、(128.72±34.53)(0.5mL/100mL/min),不同年龄组间胰腺各灌注参数差异均无统计学意义(P>0.05)。男性平均F_b、V_b、T_tp、P_S分别为(127.59±22.90)(mL/100mL/min)、(188.72±25.19)(mL/L)、(142.91±13.17)(0.1s)、(133.30±42.86)(0.5mL/100mL/min)。女性平均F_b、V_b、T_tp、P_S分别为(142.48±28.04)(mL/100mL/min)、(201.37±28.94)(mL/L)、(141.66±15.63)(0.1s)、(121.85±14.80)(0.5mL/100mL/min)。两组间比较各灌注参数差异均无统计学意义(P>0.05),胰头、胰体、胰尾血流灌注平均F_b、V_b、T_tp、P_S差异均无统计学意义(P>0.05)。结果表明,螺旋CT灌注成像技术能有效检测胰腺血流灌注,正常胰腺灌注随年龄增长有下降趋势但无统计学意义。正常胰腺灌注与年龄、性别无关,胰腺各部位灌注均匀。     

16层螺旋CT灌注成像在胰腺病变诊断中的应用

目的：应用多层螺旋CT（MSCT）灌注扫描成像技术评价正常人胰腺,胰腺炎与胰腺癌的血流动力学表现,并探讨其临床应用价值。方法：从26例行多层螺旋CT胰腺灌注扫描者中选出20例分析。胰腺癌组10例,正常胰腺组5例（志愿者）,急性水肿性胰腺炎组5例。采用GE light speed 16层CT电影模式（0．5·s^-1）,120kV,60mA,5mm×4;注射流率3．0mL·s^-1,延迟5s,扫描时间50s。应用GE ADW 4．2工作站Perfusion3灌注软件包分析,分别测量Qb,Vb,tmt和κps,采用t检验并进行统计学分析结果：所选20例受检者均获得满意的伪彩灌注图、灌注参数。胰腺癌组和正常胰腺组的灌注参数Qb、Vb、tmt和κps。均有统计学差异（P〈0．05）胰腺癌组和胰腺炎组的灌注参数Qb、Vb及tmt均有统计学差异（P〈0．05）,κps均值差异无统计学意义（P〉0．05）。胰腺炎组和正常胰腺组的灌注参数Qb、K、及κps均有统计学差异（P〈0．05）。结论：胰腺MSCT灌注成像为胰腺疾病的诊断提供了新方法,并且为治疗提供了新的理论依据。胰腺癌的血流灌注与正常胰腺和胰腺炎的血流灌注相比明显减少,MSCT灌注成像对胰腺癌血流变化的分析有一定的临床应用价值。     

动态500排联合ASiR技术对肝脏肿瘤CT灌注成像参数的影响

目的:探讨具有自适应统计迭代重建(ASi R)平台的动态500排容积螺旋穿梭技术(VHS)对肝脏肿瘤CT灌注成像参数的影响。方法:28例确诊肝脏肿瘤患者行动态首次通过法CT灌注成像检查,所得原始数据采用滤波反投影(FBP)法进行重建(重建层厚2.5 mm),测量二组图像腹主动脉CT值、噪声及肝脏肿瘤灌注参数,包括表面通透性(PS)、平均通过时间(MTT)、肝血流量(BF)、肝血容量(BV),采用Wilcoxon符号秩和检验分析两种重建算法所测量的各项灌注参数值的差异。由两名放射科医师对2组图像质量进行主观评价。结果:40% ASi R与FBP和重建算法比较:腹主动脉CT值分别为(58.33±9.19)和(58.78±9.30) HU,差异无统计学意义(P=0.258);40% ASi R组图像噪声(10.9±1.49)明显低于FBP组(13.20±1.65),差异有统计学意义(P<0.01);两种重建算法所测量的各项灌注参数(PS、MTT、BV和BF)值差异均无统计学意义(P>0.05)。40% ASi R组图像质量评分(4.25±0.42)高于FBP组(3.79±0.48),差异有统计学意义(P=0.001);两组图像的主观评分结果一致性较好(Kappa=0.821)。结论:基于ASi R平台的动态500排扫描技术在肝脏肿瘤CT灌注成像中,40% ASi R算法的图像噪声有效降低,质量显著改善。所测量的各项灌注参数与FBP重建算法相比无明显差异。     

多层螺旋CT仿真血管镜在动脉硬化症诊断中的临床应用

目的: 探讨动脉硬化症的多层螺旋CT仿真血管镜改变及诊断价值.方法:回顾性分析40例正常人血管及24例临床诊断为动脉硬化症血管的多层螺旋CT扫描资料,将所有的CT图像进行低对比(kernel≤30f)薄层(slice≤3mm)重建,然后将重建图像导入CT 3 D 工作站,用软件CT仿真内窥镜(CT-VE)、多平面成像(MPR)、最大密度投影(MIP)、容积成像技术(VRT)进行图像后处理,并就正常血管及病变血管在CT仿真血管镜中的改变进行分析和记录.结果:64例均成功地进行了CT仿真血管镜成像,40例正常组的血管仿真血管镜图像表现为血管壁光滑,管腔无狭窄;24例病变血管中,血管壁钙化24例78处,血管内壁不规则及增厚24例,血管狭窄21例.动脉硬化斑块15例48处.结论:多层螺旋CT仿真血管镜是诊断动脉硬化症的一种有效方法,其优势在于检查快速和无创伤性.     

乳腺良恶性肿块CT灌注的血流特征及临床意义

目的 探讨乳腺良恶性肿块CT灌注的血流特征及其临床意义。方法2 2例乳腺癌和11例良性肿块均为手术或穿刺活检证实。先螺旋CT平扫,选定层面行多灌注扫描。使用perfusion3软件包分别测量乳腺肿块边缘区域、肿块中心区域的血流量、血容量及表面通透性乘积,并对乳腺良性病变与乳腺癌、肿块边缘区域与肿块中心区域进行统计学分析。结果 乳腺良性肿块的周围与中心的各灌注值没有差别。良性肿块与乳腺癌BF、BV及PS的均值均有显著性差异(P<0.05);乳腺癌边缘与中心区域BF、BV及PS的均值有显著性差异(P<0.05)。结论 CT灌注可以间接地反映了乳腺肿块的生物学行为,对乳腺癌的诊断和预后评估具有重要的临床价值。     

CT灌注成像及动态增强扫描在肺部结节影像诊断中的价值初步探讨

目的:探讨CT动态增强扫描及灌注成像在肺部结节影像诊断中的价值。材料与方法:对34例肺部结节(恶性结节17例,良性结节11例,活动性炎症结节6例)进行单排螺旋CT动态增强扫描。对45例肺部结节(恶性结节24例,良性结节13例,活动性炎症结节8例)进行双排螺旋CT灌注扫描及动态增强扫描。对增强扫描病例绘出三类型结节的动态增强时间-密度曲线;对灌注扫描病例用随机灌注软件进行分析处理,得出病灶感兴趣区血流量、血容积、平均通过时间及血管表面通透性,比较三类型结节各灌注参数之间的差异。结果:良性结节动态增强时间密度曲线低平,CT值增加约10Hu;活动性炎性结节之时间密度曲线为速升速降型,CT增强值增加约62Hu;而恶性结节为速升慢降型,CT值增加约46Hu。恶性结节和活动性炎性结节的血容积及血管表面通透性值高于良性结节,良性结节的血容积值一般小于6.5mL·100g^-1,血管表面通透性值小于30mL·min^-1·100g^-1。结论:CT灌注成像可以提供肺内结节的血流灌注的定量信息,CT动态增强扫描及灌注成像有助于肺内结节的鉴别诊断。     

64排螺旋CT血管成像技术在子宫动静脉畸形中的应用

目的:探讨64排螺旋CT血管成像技术在子宫动静脉畸形(UAVM)中的临床价值。方法:选取2例UAVM患者64排螺旋CT数据,所有扫描图像均采用冠状多平面重组(MPR)、最大密度投影(MIP)及容积再现(VR)技术进行三维重建。结果:2例患者64排螺旋CT三维成像均能清晰显示骨盆、髂总动脉、髂外动脉及其分支、髂内动脉及子宫动脉等,可以确定UAVM血管团的位置、大小、供血动脉、引流静脉的情况及与毗邻血管、骨盆的立体空间关系。结论:64排螺旋CT血管成像技术能准确诊断UAVM,为临床诊治提供清晰及立体的影像资料。     

A Monte Carlo study of rainfall forecasting with a stochastic model

A procedure for short-term rainfall forecasting in real-time is developed and a study of the role of sampling on forecast ability is conducted. Ground level rainfall fields are forecasted using a stochastic space-time rainfall model in state-space form. Updating of the rainfall field in real-time is accomplished using a distributed parameter Kalman filter to optimally combine measurement information and forecast model estimates. The influence of sampling density on forecast accuracy is evaluated using a series of a simulated rainfall events generated with the same stochastic rainfall model. Sampling was conducted at five different network spatial densities. The results quantify the influence of sampling network density on real-time rainfall field forecasting. Statistical analyses of the rainfall field residuals illustrate improvement in one hour lead time forecasts at higher measurement densities.     

Earthquake Engineering and Engineering Vibration Aims And Scope

正This journal is established by the Institute of Engineering Mechanics(IEM),China Earthquake Administration,to promote scientific exchange between Chinese and foreign scientists and engineers so as to improve the theory and practice of earthquake hazards mitigation,preparedness,and recovery.To accomplish this purpose,the journal aims to attract a balanced number of papers between Chinese and     

Foreword

Destructive earthquakes have caused great damage in China and the United States and collapsing buildings havecaused many deaths and injuries. The field of earthquake engineering studies earthquake hazards, the occurrence ofearthquakes of various magnitudes, the nature of the ground shaking during an earthquake, the vibration of structuresduring earthquakes, the strengthening of existing structures and the design of new structures to be earthquake resistant,and finally, how to cope with earthquake damage and restore a city to normal functioning. Such efforts are in progressin both countries, but unfortunately, the language barrier interferes with the free flow of information between China andthe Untied States. It would be mutually beneficial if some means could be developed to promote the exchangeof information across the Pacific Ocean. This new journal has been established for this purpose and its success willbe an important step in promoting earthquake engineering in China and the United States.     

WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)

正President:Giampaolo Di Silvio,Italy Vice Presidents:Ulrich C.E.Zanke,Germany Zhao-yin Wang,China The World Association for Sedimentation and Erosion Research(WASER),inaugurated on Oct.19,2004,is an independent non-governmental,non-profit organization.The mission of WASER is to promote international co-operation on the study     

Enhancing remote sensing research on global change to improve our understanding on Earth system processes

正Global Change includes climate change and other environmental changes caused by the joint interaction among various layers of Earth. From the positive side, global change provides new opportunities to human and other living forms on Earth. In the meantime, it creates tremendous challenges and negative impact. At present, the negative impacts have reached all primary processes of the global ecosystem and every aspect of human society, especially causing degradation of the ecosystem. For instance, intensive deforestation causes decline of biodiversity; global warming causes sea level rise and increases     

Solute concentrations in the lower niger river and the source rock contribution

Water quality analyses for the Niger River for the 1980/81 hydrological year are presented. The samples were collected from the main river at Lokoja, and from two main tributaries, the Kaduna and the Benue Rivers. Different water types were distinguished by the concentrations of major ions. The type Ca > Na > Mg > K - HCO₃ > SO₄ > Cl was represented at all stations during at least part of the year. Chloride was found to dominate the sulphate ion in the Kaduna and Niger, while the Benue maintained a higher concentration of sulphate relative to chloride all year round. Distinct patterns of seasonal variation in the ion concentrations were observed, particularly for the samples collected at Lokoja. Low ion concentrations were prominent during periods of high discharge, while low flow periods coincided with high dissolved ion concentrations. The contribution of rainwater to the total dissolved solids in the river waters was assessed indirectly using rainwater chemistry data from the Gulf of Guinea. The estimated rainwater contribution to the Lower Niger amounts to 5.15 mg 1^?1. Geochemical weathering calculations involving reactions of the four major minerals of granitic rocks - anorthite, biotite, albite, and K-feldspar - with carbon dioxide and water, can account for the average water composition of the Lower Niger. The proportion of the ionic components was also related to the occurrence of the respective element in the minerals.