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目的是评价气囊加压快速静脉滴注在ＣＴ增强扫描中的应用价值。材料与方法采用６０％泛影葡胺或Ｏｍｎｉｐａｑｕｅ（３００ｍｇ／ｍｌ）１００ｍｌ造影输血器,常规做碘过敏试验,阴性者穿刺最佳静脉,将血压计气囊连续在胶管上,快速挤压气囊,使空气进入造影剂瓶内,造影剂注入速度达４－５ｍｌ／ｓ。注射前,常规给以１０ｍｇ地塞米松,并将造影剂加热至３７℃左右,尽量减少副反应发生的几率,结果得到了：在没有高压注射器的条 相似文献
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目的:探讨3种不同肠道准备方法在CT小肠造影（CTE）中的应用价值。方法:对156例临床怀疑为小肠病变而行CTE的病例进行前瞻性研究。156例随机分为A、B和C组各52例,肠道造影剂均采用口服法。A和B两组在扫描前16h进食半流质饮食,并均以番泻叶6g导泄,扫描前12h禁食,扫描前1h起每隔15min A组尽量口服等渗甘露醇、B组同法尽量口服引用水。C组扫描前6h禁食,扫描前1h起每隔15min尽量口服饮用水。3组均在口服对比剂10min后进行CTE检查。统计比较3组小肠的充盈效果及对小肠病变的诊断价值。结果:小肠充盈效果比较A组最佳,B组次之,C组最差;对小肠病变的诊断结果显示A组对小肠各段病变的诊断价值均较显著;B组对十二指肠、空肠病变诊断价值较大,对回肠的细小病变诊断效果较差;C组对十二指肠及空肠上段病变诊断效果较好,但不利于空肠上段以远细小病变的诊断。结论:充分的肠道准备是CTE的重要技术因素,分次口服等渗甘露醇尽量充盈小肠有利于小肠病变的显示,是一种安全可靠、经济方便的肠道准备方法。 相似文献
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目的:探讨患者螺旋CT经下肢静脉注射造影剂增强检查的最佳扫描参数,以便经下肢静脉注射造影剂达到经上肢静脉注射造影剂螺旋CT增强检查诊断图像效果。资料与方法:收集400例患者CT增强检查资料。其中实验组200例,由于长期上肢静脉注射造成静脉血管损伤严重的患者,在进行增强CT检查中,采取经下肢静脉(脚、踝部静脉血管为主)注射造影剂螺旋CT增强检查,注射速率以2.5～3.3mL/s,非离子型造影剂70～100mL,动脉期及静脉期根据组织器官均较上肢静脉注射造影剂延长延迟时间8～15s,螺旋CT扫描范围包括检查器官上下范围,病变区加扫薄层;对照组200例,经上肢肘静脉注射造影剂增强CT检查患者,依组织器官不同注射速率、非离子型造影剂量及螺旋CT扫描范围方法与实验组相同,动脉期及静脉期根据组织器官注射造影剂设定延迟时间。分析测量两组CT图像正常组织、血管及病变组织CT值和扫描曲线,进行统计学分析。结果:200例实验组经下肢静脉(脚、踝部静脉血管为主)注射造影剂螺旋CT增强检查病例与对照组200例经上肢肘静脉注射造影剂增强CT检查患者,增强检查图像质量经统计学分析相近。上肢动脉期CT值和下肢动脉期CT值配对比较,统计学分析t值为4.371,P=0.000,这两组存在显著性差异,具有统计学意义,即上肢动脉期CT值和下肢动脉期CT值存在差异。上肢静脉期CT值和下肢静脉期CT值配对比较,t值为-1.664,P=0.103>0.05,这两者的差异没有统计学意义,没有显著性差异,即上肢静脉期CT值和下肢静脉期CT值差异没有统计学意义,二者不存在差异性。结论:长期上肢静脉注射造成静脉血管损伤严重患者,经下肢静脉注射造影的增强扫描采取适当的增加延迟时间扫描完全可以达到上肢静脉注射造影剂螺旋CT增强扫描图像质量。 相似文献
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本文分析及总结了ＣＴ动态２增强扫描中使用的６０％泛影葡胺造影剂的最优化剂量，以减少病人副反应发生发生率。根据泛影葡胺的理化特性及反应发生机理及注入体内不同组织时间的一密度曲线，经２００例分组实验和１５００例临床应用证明ＣＴ动态增强扫描注入造影剂的最优化剂量为６０ｍｌ／次，从而取代过去的１００ｍｌ／次。 相似文献
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目的是评价改进了ＣＴ扫描及准备方法在消化道疾病的诊断中所起的作用及其指导治疗和判断预后的深远意义。材料和方法采用特定的肠道准备方法。应用改良后的扫描技术,与消化道钡餐餐透视及其消化道内窥镜检查结果相对比,对３２例患有消化道疾病的患者进行认真研究,全部结果经病理和临床证实。结果根据Ｄｕｋｅｓ改良分期法。所有肿瘤患者均为Ⅱ期或Ⅱ期以上。诊断中有４例误诊,定性诊断的正确率为８７．５％,所有病灶的检出率为 相似文献
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弓形虫病（ｔｏｘｏｐｌａｍｏｓｉｓ）是由刚地（ｇａｎｄｉｉ）弓形引起的一种寄生虫病。世界各地广泛分布,中国从１９５７年开始报告临床病例,但脑电改变报告不多。本文拟就探讨其脑电及ＣＴ的变化。所有２４例病人均经间接血凝试验（ＩＨＡ）检查明确诊断,并做脑电检测及头颅ＣＴ扫描。结果发现２４例脑电全部为程度不等的异常,异常率１００％。头颅ＣＴ扫描２０例中有８例阳性病灶,阳性率４０％。结论是系统症状原弓形虫感 相似文献
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是探讨ＣＴ增强扫描中降低造影剂副反应的基本原则和处理措施。材料和方法：对１８００例ＣＴ增强扫描病例进行造影剂应用的选型和预防性给药,对其中出现的造影剂副反应进行分类、记录和总结并提出具体的处理措施。结果：应用离子型造影剂副反应发生率为５．０４％,应用非离子型造影剂副反应发生率为０．９％。结论：合理选择造影剂、严格筛选高危人群和预防性给药以及完备的抢救措施能明显降低造影剂的副反应率和致死率。 相似文献
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评价高分辨率ＣＴ（ＨＲＣＴ）扫描在运气了管扩张诊断中的应用价值。分析１９例支气管扩张的ＨＲＣＴ表现并与Ｘ线平电及常规ＣＴ扫描进行比较。本组柱状支气管扩张占６３．６％，静脉曲张型支气管扩张占２６．３２％，囊状支气管扩张占１０．５２％，扩张的支气管管壁厚度在１－３ｍｍ之间。ＨＲＣＴ扫描是诊断支气管扩张最安全，准确，可靠的方法之一。 相似文献
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Budd—Chiari综合征的CT评价 总被引：2，自引：0，他引：2
回顾性分析了５２例Ｂｕｄｄ－Ｃｈｉａｒｉ综合征的ＣＴ表现，ＣＴ显示肝尾叶增大５０例（９６％），肝脏呈低度密度或密度不均，４２例（８１％）肝静脉未明显，２２例（４２％）见有肝内侧枝血管，４９例（９４％）有肝外侧枝血管，作者认为ＣＴ检查对Ｂｕｄｄ－Ｃｈｉａｒｉ综合征有较高的诊断价值。 相似文献
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本文探讨眼球内肿瘤的ＣＴ表现特点。地３０例经手术和病理证实的眼球内肿瘤的ＣＴ片进行了回顾性分析和总结。ＣＴ在眼内肿瘤的诊断上有以下优势：（１）可以弥补眼底镜检，荧光血管造影以及超声波之不足；（２）高分辨率ＣＴ及薄层扫描能较好的显示眼内肿瘤其伴存的钙化，出血等，以及向眼球外扩展的程度。结论：目前ＣＴ为诊断眼球肿瘤的常用检查方法。 相似文献
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K. Adalier A. Elgamal J. Meneses J. I. Baez 《Soil Dynamics and Earthquake Engineering》2003,23(7):571-584
In many cases densification with vibro-stone columns cannot be obtained in non-plastic silty soils. Shear stress re-distribution concepts [1] have been previously proposed as means to assess stone columns as a liquefaction countermeasure in such non-plastic silty soils. In this study, centrifuge testing is conducted to assess the performance of this liquefaction countermeasure. Attention is focused on exploring the overall site stiffening effects due to the stone column placement rather than the drainage effects. The response of a saturated silt stratum is analyzed under base dynamic excitation conditions. In a series of four separate model tests, this stratum is studied first without, then with stone columns, as a free-field situation, and with a surface foundation surcharge. The underlying mechanism and effectiveness of the stone columns are discussed based on the recorded dynamic responses. Effect of the installed columns on excess pore pressures and deformations is analyzed and compared. The test results demonstrate that stone columns can be an effective technique in the remediation of liquefaction induced settlement of non-plastic silty deposits particularly under shallow foundations, or vertical effective stresses larger than about 45 kPa (1000 psf) in free field conditions. 相似文献
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目的:通过回顾性分析血管源性急腹症患者的增强CT表现、临床特征及超声结果,以总结诊断经验,提高对此类患者的诊断水平。方法:回顾性分析自2012年1月至2017年3月在我院急诊科以腹痛为主诉就诊并行急诊腹部CT检查的患者,选取CT影像表明其为血管源性,且临床确诊为血管源性急腹症的患者共156例,根据不同的血管病变类型及受累的血管不同,分为5大类疾病,并分别统计各类疾病的病例数、典型CT影像表现及超声阳性率。结果:156例患者共分为以下5大类疾病:①动脉夹层及动脉瘤53例,其中动脉夹层17例,包括15例为胸主动脉夹层向下延续,1例单发于腹主动脉下段局限小夹层,1例腹主动脉至右髂总动脉夹层;动脉瘤36例,其中腹主动脉瘤30例、腹主动脉假性动脉瘤3例、1例脾动脉假性动脉瘤、1例腹主动脉瘤支架术后破裂形成血肿、1例单纯右侧髂总动脉瘤。②肠系膜血管疾病30例,其中肠系膜上动脉栓塞12例、肠系膜下动脉栓塞1例、肠系膜静脉栓塞15例（其中5例合并门脉栓塞）、1例肠系膜上动脉夹层、1例肠系膜上动脉壁间血肿。③门脉系统疾病52例,其中门脉高压19例,门脉血栓17例,门脉癌栓9例,门脉海绵样变3例,门脉积气4例。④脾梗死或肾梗死共12例。⑤其他类型血管源性急腹症共9例。结论:增强CT检查在诊断血管源性急腹症比CT平扫、超声检查有更大的优势,不同类型血管源性急腹症有不同的典型CT表现,临床及影像科医生均需要加强对该病的认识和重视程度,总结诊断经验,减少误诊和漏诊,最终提高对此类患者的诊断水平。 相似文献
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目的:探讨早期中央型肺癌的多排螺旋CT的征象、诊断及漏误诊原因,以提高早期中央型肺癌的MSCT诊断水平。方法:对29例由病理证实的早期中央型肺癌的CT资料分析MSCT的主要征象、诊断及漏误诊的因素。结果:CT诊断或拟诊中央型肺癌24例,肺炎1例,支气管扩张伴感染1例,结核1例,漏诊2例,并分析出漏误诊病例的原因。早期中央型肺癌主要CT表现有:支气管腔内结节,支气管管壁的增厚、管腔的狭窄,支气管铸型阴影,阻塞性肺炎与肺不张等。结论:早期中央型肺癌的MSCT检查、多维重建及熟悉CT主要征象对发现早期病变并准确诊断具有重要意义,熟悉掌握支气管的CT解剖结构、良好的读片观察习惯、仔细重建有利于提高早期中央型肺癌的诊断。 相似文献
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目的:探讨螺旋CT各参数鉴别尿路结石成分的价值。方法:收集2016年5月至2018年3月我院112例尿路结石患者的术前CT图像资料,测量尿路结石直径（d）、平均CT值（HUm）及CT值标准差（HUsd）,并计算平均CT值/直径的比值（HUd）,再以术后红外线光谱结果为参照标准,比较各类结石成分d、HUm、HUsd及HUd的差异,并运用受试者工作特征曲线（ROC曲线）评价其鉴别结石成分的效能。结果:尿酸结石21例、一水草酸钙结石49例、碳酸磷灰石10例和混合结石27例,尿酸结石的HUm、HUsd及HUd值均明显低于其他类型结石;尿酸结石与非尿酸结石（一水草酸钙结石、碳酸磷灰石、混合结石）之间的HUm、HUsd及HUd值差异均有统计学意义（P<0.05）;非尿酸结石之间的HUm、HUsd及HUd值差异均无统计学意义（P>0.05）;各类结石的d值差异均无统计学意义（P>0.05）;d、HUm、HUsd及HUd鉴别尿酸结石的ROC曲线下面积（AUC）为0.444、0.915、0.972及0.858。结论:螺旋CT的HUm、HUsd及HUd值均能鉴别尿酸结石和非尿酸结石,其中以HUsd的鉴别效能最佳,但不能区分各类型非尿酸结石。 相似文献
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Many surviving ancient monuments are freestanding stone masonry structures, which appear to be vulnerable to horizontal dynamic loads such as earthquakes. However, such structures have stood for thousands of years despite numerous historic earthquakes. This study proposes a scaled-down dynamic centrifuge modelling test to study how these masonry structures resist seismic loading. The test is proposed for seismic risk assessments to evaluate risk of damage from a future seismic event. The seismic behaviour of a 3-storey, freestanding stone block structure has been modelled and tested within a centrifuge. Models were made at 3 different scales and dynamic tests were conducted using different centrifugal acceleration fields so that the behaviours could be transformed to an equivalent full-scale prototype and compared. Data from 2 earthquakes and a sweeping signal were used to simulate the effects of earthquake ground motion within the centrifuge. The acceleration and frequency responses at each storey height of the model were recorded in different centrifugal acceleration fields. Similar behaviours appeared when the results of the small-scale models were transformed to a full-size prototype scale. This confirms that the seismic behaviour of stone masonry structures can be predicted using scaled-down models. 相似文献
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目的探讨CT对输尿管结石的诊断价值.方法对57例经临床证实为输尿管结石患者的CT表现进行回顾性分析.结果①CT对输尿管结石确诊55例(96.5%);②输尿管下段结石39例(68.4%),中上段结石18例(31.6%);③结石在CT图像上均为高密度;④CT对结石引起的继发性改变,显示效果较好.结论:CT对输尿管结石的检查优于X线平片及B超,尤其是对输尿管下段小结石的显示较佳. 相似文献
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The automotive industry plays a major role in the worldwide economy and represents an opportunity to increase the performance of the Turkish economy. Phosphating units in the automotive manufacturing plants generate phosphate sludge as waste, which is classified as hazardous waste in the European Waste Catalogue. Phosphate sludge must be disposed of in licensed disposal plants according to the current environmental regulations. Solidification/stabilization (S/S) is a widely used treatment technology for the disposal of hazardous wastes. Portland cement is used for the solidification and stabilization processes to immobilize Ni and Zn in the phosphate sludge as well as to create construction material to be used as cobble stone for pavement. Examination of products obtained by S/S processes is performed for two points: to determine the quality and to assess the environmental impacts. The phosphate sludge samples are subjected to chemical characterization and a size distribution analysis leaching test. Concrete for cobble stone was produced by the S/S process with the addition of phosphate sludge to replace sand. Tests for the quality of the product were carried out to determine compressive strength, permeability, and elasticity. At the end of the leaching test, elution concentrations of Zn and Ni while using water with pH values of 4.0, 5.4, and 9.0 were determined to be under the limit of inert material properties. Use of phosphate sludge should be considered as a sand replacement in the proportion of 1% of phosphate sludge to cement in concrete production, such as for cobble stone for pavement, without any adverse environmental impacts. 相似文献
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Building sandstone surface modification by biofilm and iron precipitation: emerging block‐scale heterogeneity and system response 
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下载免费PDF全文 Stephen McCabe Daniel McAllister Patricia A. Warke Miguel Gomez‐Heras 《地球表面变化过程与地形》2015,40(1):112-122
Stone surfaces are sensitive to their environment. This means that they will often respond to exposure conditions by manifesting a change in surface characteristics. Such changes can be more than simply aesthetic, creating surface/subsurface heterogeneity in stone at the block scale, promoting stress gradients to be set up as surface response to, for example, temperature fluctuations, can diverge from subsurface response. This paper reports preliminary experiments investigating the potential of biofilms and iron precipitation as surface‐modifiers on stone, exploring the idea of block‐scale surface‐to‐depth heterogeneity, and investigating how physical alteration in the surface and near‐surface zone can have implications for subsurface response and potentially for long‐term decay patterns. Salt weathering simulations on fresh and surface‐modified stone suggest that even subtle surface modification can have significant implications for moisture uptake and retention, salt concentration and distribution from surface to depth, over the period of the experimental run. The accumulation of salt may increase the retention of moisture, by modifying vapour pressure differentials and the rate of evaporation. Temperature fluctuation experiments suggest that the presence of a biofilm can have an impact on energy transfer processes that occur at the stone surface (for example, buffering against temperature fluctuation), affecting surface‐to‐depth stress gradients. Ultimately, fresh and surface‐modified blocks mask different kinds of system, which respond to inputs differently because of different storage mechanisms, encouraging divergent behaviour between fresh and surface‐modified stone over time. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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目的：提升对CT诊断Med-Dlbcl的认识。资料和方法：女性7例,男性4例,年龄23～42岁,回顾性的分析11例Med-Dlbcl的CT征象。结果：11例Med-Dlbcl病例中,CT误诊为胸腺瘤9例,仅2例考虑到Med—Dlbcl的可能性。讨论：随着Med-Dlbcl的发病率在中国逐年上升,CT医师应该提升对该疾病诊断的认识。 相似文献