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目的:探讨肺部肿块的CT血流灌注的特征及临床价值.方法:对35例患者(男21例,女14例;平均年龄,64.7岁,年龄范围,24～83岁)进行CT灌注检查.使用64排螺旋CT,先平扫有问题的结构区域,然后选定肿块扫描层面,使用高压注射器,经肘静脉注入50mL·300mg·100mL-1的优维显,速率为4mL·s-1,延迟5 s后,以电影模式行多层灌注扫描,持续35～40 s.使用Perfusion 3灌注软件测量血容量及表面透过性乘积.3个独立样本(肺癌组、结核组及炎症组)两两进行统计学分析(t检验).结果:恶性肿块20例(4例鳞癌,12例腺癌,1例未分化癌,3例转移癌),炎性肿块8例,结核灶7例.肺癌、结核灶及炎性肿块的灌注均值(BV和PS)分别为:(8.43±2.44)mL·100g-1,(24.30±5.80)mL·min-1·100g-1;(1.90±0.60)mL·min-1·100g-1,(1.19±0.37)mL·min-1·100g-1;(19.73±6.65)mL·100g-1,(30.01±9.06)mL·min-1·100g-1.肺癌组与结核灶组及炎性肿块组与结核灶组之间的灌注均值均有显著差异(p<0.05);肺癌组与炎性肿块组之间的BV均值有显著差异(p=0.014,t=2.639),但二者PS均值无统计学意义(p=0.506,t=0.674).结论:利用灌注值可以区分肺癌与结核灶、炎性肿块与结核灶,虽然单独依靠灌注值很难区分肺癌与炎性肿块,但是血流灌注仍间接反映了肺部肿块的生物学行为. 相似文献
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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。 相似文献
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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 相似文献
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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。 相似文献
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16层螺旋CT灌注成像在胰腺病变诊断中的应用 总被引：2，自引：1，他引：1
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。 相似文献
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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。 相似文献
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乳腺良恶性肿块CT灌注的血流特征及临床意义 总被引：1，自引：0，他引：1
祖德贵 《CT理论与应用研究》2006,15(3):26-30
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22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。 相似文献
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多层螺旋CT仿真血管镜在动脉硬化症诊断中的临床应用 总被引：11，自引：4，他引：7
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. 相似文献
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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。 相似文献
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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. 相似文献
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Gtz Schroth Luciana Ferreira Da Silva Marc‐Andree Wolf Wenceslau Geraldes Teixeira Wolfgang Zech 《水文研究》1999,13(10):1423-1436
The partitioning of rain water into throughfall, stemflow and interception loss when passing through plant canopies depends on properties of the respective plant species, such as leaf area and branch angles. In heterogeneous vegetation, such as tropical forest or polycultural systems, the presence of different plant species may consequently result in a mosaic of situations with respect to quantity and quality of water inputs into the soil. As these processes influence not only the water availability for the plants, but also water infiltration and nutrient leaching, the understanding of plant effects on the repartitioning of rain water may help in the optimization of land use systems and management practices. We measured throughfall and stemflow in a perennial polyculture (multi‐strata agroforestry), monocultures of peach palm (Bactris gasipaes) for fruit and for palmito, a monoculture of cupuaçu (Theobroma grandiflorum), spontaneous fallow and primary forest during one year in central Amazonia, Brazil. The effect on rain water partitioning was measured separately for four useful tree species in the polyculture and for two tree species in the primary forest. Throughfall at two stem distances, and stemflow, differed significantly between tree species, resulting in pronounced spatial patterns of water input into the soil in the polyculture system. For two tree species, peach palm for fruit (Bactris gasipaes) and Brazil nut trees (Bertholletia excelsa), the water input into the soil near the stem was significantly higher than the open‐area rainfall. This could lead to increased nutrient leaching when fertilizer is applied close to the stem of these trees. In the primary forest, such spatial patterns could also be detected, with significantly higher water input near a palm (Oenocarpus bacaba) than near a dicotyledonous tree species (Eschweilera sp.). Interception losses were 6·4% in the polyculture, 13·9 and 12·3% in the peach palm monocultures for fruit and for palmito, respectively, 0·5% in the cupuaçu monoculture and 3·1% in the fallow. With more than 20% of the open‐area rainfall, the highest stemflow contributions to the water input into the soil were measured in the palm monocultures and in the fallow. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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M. N. French R. L. Bras W. F. Krajewski 《Stochastic Environmental Research and Risk Assessment (SERRA)》1992,6(1):27-45
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. 相似文献
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M. A. Kahn 《洁净——土壤、空气、水》2000,28(2):95-101
Red tide, a recurrent phenomenon has become conspicuous in several Kashmir lake ecosystems since 1991. The responsible organism (Euglena pedunculata), a rare flagellate rediscovered in the Kashmir Himalaya (Khan 1993) caused first and unprecedented red tide outbreak, constituting a maximum of 96% of resident numerical phytoplankton density in Dal Lake. At present, conflicting hypotheses exist on the generation of causal assemblage(s) imparting redness to waters: Jeeji Bai (1991) linked its origin to acid precipitation – a fallout of burning oil‐fields during the Gulf War – whilst Khan (1993) holds local factor(s) responsible. Field/experimental studies support the latter contention that the influx of untreated sewage, in unison with warm temperatures, high levels of PhAR, iron and interruption to hydrological flow‐pattern together with absence/or reduction in grazing activity created conducive environmental milieu for red tide outbreak. Dal Lake “red tide” drifted the bloom‐inoculum to other waters, including Lake Wular, where additional ecological niches were carved out, threatening the aesthetic value and biological diversity of Kashmir lakes. Ecological monitoring indicates frequent seasonal red tide occurrence in Dal Lake (including summer‐autumn event of 1998) which testifies its unabated eutrophication status. Further studies are needed on ecological adaptability and biogeographic distribution of this rare and unique red tide‐causing flagellate. 相似文献