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目的：探讨磁共振胰胆管成像（MRCP）和常规MRI对胆囊增大的诊断价值。方法：回顾性分析经腹腔镜或外科手术证实的29例胆囊增大病人的临床和影像资料。对每一例患者在术前行MRCP和常规轴面T1WI与T2WI联合检查,将影像诊断与手术所见及病理诊断结果对照,评价术前MRCP和MRI对胆囊增大病因的诊断正确率。结果：①本组增大胆囊的长径范围为8.01～18.13cm（平均11.93cm±3.20）,横径范围为4.12～7.05cm（平均4.59cm±0.91）;②29例胆囊增大的病因诊断如下：与胆道结石相关的良性病变17例（胆总管结石7例、急性与慢性胆囊炎伴胆囊结石4例、胆囊腺肌瘤病和Mirizzi综合征各3例）,低张力胆囊1例,MRCP和MRI的诊断敏感度为83.33%（15/18）,特异度为72.22%（13/18）;由肿瘤性病变引起的胆囊增大11例（胆囊癌1例、肝门胆管癌1例、胆总管癌5例及壶腹周围癌4例）,MRCP和MRI的诊断敏感度为90.90%（10/11）,特异度为81.81%（9/11）。结论：胆囊增大可由良、恶性胆囊疾病与肝外胆管梗阻性病变引起,MRCP和常规MRI联合检查有助于明确病因诊断。 相似文献
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目的总结并分析海绵窦海绵状血管瘤(CSHas)的影像学表现。方法回顾性分析了6经手术病理证实的发生于海绵窦部的绵状血管瘤影像学资料结果6例病变中4例表现为T1稍低信号,2例表现为等信号,4例在平扫CT中为稍高密度影,增强扫描所有病例均呈现不均匀的明显对比增强。结论海绵窦部的海绵状血管瘤的影像表现有一定特点,有助于海绵窦部占位病变的诊断及鉴别诊断。 相似文献
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目的:探讨MSCTA腹部血管成像对肝脏肿瘤的介入治疗操作的指导价值.材料和方法:对于37例介入手术病例进行术前常规MSCTA腹部血管成像检查,术前多平面、多角度分析腹腔干开口位置;肝脏及肿瘤血管各分支开口部位、走行方向;肿瘤供血动脉和变异等细节,进而指导介入手术中的插管操作.结果:术前MSCTA清晰显示正常解剖腹腔干动脉及肠系膜上动脉开口16例,开口位置偏移9例,腹腔干动脉及肠系膜上动脉开口共干4例,腹腔干动脉闭锁2例.32例清晰显示腹腔干动脉,肝总动脉,肝固有动脉分支及走行方向.29例显示了肿瘤供血动脉,2例显示出变异肿瘤血管.结论:由于术前有MSCTA指导肝脏相关血管的分支走行信息,使介入操作能更准确地控制导管进入到靶血管中,明显减少了插管的时间,提高了肝脏肿瘤TACE介入治疗的成功率,TACE术前常规对患者进行MSCTA腹部血管成像对介入操作有很高的指导价值. 相似文献
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目的:探讨MSCT对肝外型肝癌的影像诊断。方法:搜集经手术病理证实的肝外型肝癌12例,其中男性8例,女性4例,年龄19～56岁,平均年龄37.5岁。所有病例均行CT平扫、增强及三维重建。分析MSCT三维重建对肝外型肝癌的诊断价值。结果:在本组12例肝外型肝癌中,8例存在肝硬化。肿块位于肝左叶旁6例,肝右叶旁5例,尾状叶旁1例;肿块5例以囊变为主,7例以实性部分为主,少有囊变;动脉期MSCTA显示6例由肝右动脉供血,4例由肝左动脉供血,1例由胃右动脉供血,1例由胃十二指肠动脉供血。本组12例均未见门静脉瘤栓形成。结论:MSCT三维重建可以显示肝癌的供血动脉,对肝外型肝癌有重要的诊断价值。 相似文献
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目的:探讨增强CT成像对肝窦阻塞综合征（HSOS）的诊断价值。材料和方法:收集临床和影像诊断为HSOS的6例（男2例,女4例）纳入本研究,所有患者均行增强CT检查,观察分析增强CT成像上肝实质、肝脏相关血管及其他扫描范围相关影像变化,并参考肝脏血管超声、血管造影或增强MR检查结果,总结分析HSOS增强CT的特征。结果:CT平扫6例均表现肝脏肿大,肝实质密度不均匀减低。增强后6例均表现为“斑片状”或“地图样”异常强化,1例除此之外还可见特征性的以第二肝门为中心沿三支肝静脉周围“放射状”异常强化。5例三支肝静脉均未见显示,1例肝左静脉未显影,肝中静脉和肝右静脉变细成线样改变。下腔静脉肝段3例重度狭窄,3例稍受压,但所有病例经肝脏血管超声、血管造影或增强MR检查均证实肝静脉及下腔静脉血流通畅。结论:CT平扫所显示肝脏肿大、密度不均匀减低和增强扫描所显示肝实质“斑片状”或“地图样”异常强化或特征性的以第二肝门为中心沿三支肝静脉周围“放射状”异常强化特点有助于HSOS的诊断。但增强CT对诊断肝静脉和下腔静脉肝段是否狭窄或闭塞有一定的局限性。 相似文献
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王海 《CT理论与应用研究》2001,10(2):30-32
目的：探讨小肝细胞癌和肝脏小血管瘤螺旋CT增强表现及其随时间延迟所致的CT征象的变化过程，材料与方法：50例患者（15例SHCC，35例SHHE），其中19例经手术病理标本证实，其余患者由临床表现和实验室检查诊断，采用Siemens Plus4C螺旋CT机，先作平扫，然后在肿瘤靶平面平衡期扫描。着重观察，分析不同CT扫描时相小肝细胞癌和肝脏小血管瘤CT表现特征的动态变化过程，结果，SHHE组发现病灶44个，30个病灶在动脉期动缘明显强化逐渐向中心填充，22个病灶在动脉期和门静脉期均为高密度，2个病灶在动脉期和门静脉期均为底密度，在平衡期42个病灶SHHE为高密度和等密度SHCC组发现二18个，14个病灶SHCC显示动脉期呈高密度、门静脉期为低密度，3个病灶动脉期为高密度、门静脉期为等密度、1个病灶动脉期、门静脉期均为低密度，平衡期16个病灶的SHCC为低密度，结论：根据SHHE和SHCC在螺旋CT多期扫描的强化表现，大多数病例可明显两者诊断。 相似文献
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目的：评价CT血管成像（CTA）在主动脉缩窄的诊断与随访中的应用价值。方法：回顾性分析17例主动脉缩窄患者的CTA资料,其中6例有术后随访资料。通过多平面重组（MPR）、容积再现（VR）、最大密度投影（MIP）等多种图像后处理方法对其进行评价。结果：17例主动脉缩窄患者,男10例,女7例,其中导管旁型8例,导管前型4例,导管后型5例;5例行外科旁路搭桥手术,1例行血管置换手术,1例行球囊扩张手术;3例合并其他畸形,包括1例双上腔静脉,1例动脉导管未闭,1例肺静脉异位引流;17例患者可见不同程度的侧枝循环形成,支气管动脉、肋间动脉、胸廓内动脉增粗;5例手术患者旁路血管管腔通畅。结论：CT血管成像能很好地显示主动脉缩窄,对并发畸形、侧枝循环能良好显示,在术前评估、术后随访中起非常重要的作用。 相似文献
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目的：探讨双源CT双能量虚拟平扫（VNC）对直肠癌壁外血管侵犯（EMVI）的术前诊断价值。方法：选取2019年11月至2021年12月间拟手术治疗的150例直肠癌患者术前行双源CT双能量虚拟平扫，女性64例（42.7%）、男性86例（57.3%），平均年龄为（62.3±11.8）岁。两名高年资影像科医师独立分析术前影像资料（包括ctEMVI情况及有无局部淋巴结浸润和远处转移），判断是否存在术前EMVI。以手术病理结果为金标准，分别评价VNC诊断EMVI的敏感性、特异性、准确性、阳性预测值和阴性预测值并采用受试者操作特征（ROC）曲线下面积评价其诊断效能。结果：150例直肠癌患者中，术后病理证实56例（37.3%）为EMVI阳性，94例（62.7%）为EMVI阴性。医师1对EMVI评价准确性、敏感性、特异性、阳性预测值、阴性预测值分别为86%、80.36%、89.36%、81.82%、88.42%,AUC为0.831(95%CI 0.756～0.905)；医师2的准确性、敏感性、特异性、阳性预测值、阴性预测值分别为88.67%、80.36%、93.62%、88.24%、88.89%,AU... 相似文献
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目的:分析腮腺常见良性肿瘤的临床表现及CT表现,以提高其术前诊断准确率。资料与方法:回顾性分析45例经手术病理证实为腮腺良性肿瘤患者的临床资料及CT影像资料,结合文献并总结其临床及影像学表现特征。结果:45例患者中,形态规则,多形性腺瘤24例（均为单发）,基底细胞腺瘤6例（均为单发）,腺淋巴瘤15例（单发5例,多发10例,双侧多发5例）。10例腺淋巴瘤患者有长期吸烟史;多形性腺瘤表现为渐进性强化;基底细胞腺瘤表现为动脉期和静脉期显著强化,静脉期较动脉期稍减退;腺淋巴瘤表现为“快进快出”,可有血管贴边征;三者增强方式不同,其强化差异有统计学意义（P<0.05）。结论:腮腺常见良性肿瘤具有一定CT特征表现,结合患者临床表现,有利于提高其术前诊断准确率。 相似文献
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目的:研究64排螺旋CT血管造影对主动脉夹层的诊断价值。方法:回顾性分析我院2009年至2011年上半年,经64排螺旋CT诊断为主动脉夹层的病例10例,其中6例经DSA证实诊断并治疗。结果:CT诊断Stanford B型6例,Stanford A型4例。Stanford B型6例均行介入腔内支架封堵术,术后分型诊断与CT完全符合。Stanford A型4例,临床认为不适合行介入手术支架治疗,经内科保守治疗,未行手术治疗。结论:64排螺旋CT血管造影不仅能准确地诊断主动脉夹层动脉瘤,而且能正确地分型及指导治疗。 相似文献
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I. A. Ansari 《洁净——土壤、空气、水》1987,15(2):175-178
This paper deals with the toxicity of sodium nitrite to freshwater fishes, Channa punctatus (BL.) and Mystus (M). vittatus (Bl.) as to determine the acute toxicity. The LC 50 values were obtained by using a static bioassay method for a period of 24, 48, 72 and 96 hour intervals. The LC 50 values of sodium nitrite for C. punctatus were 375, 325, 250 and 200 ppm and for M. (M). vittatus 164, 140, 90 and 64 ppm, respectively. A profuse mucus secretion was evident at higher concentrations as compared to lower ones. The probable causes of mortality of the fishes are also discussed. 相似文献
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Comparison of two methods for ground level vapour sampling and influence of meteorological parameters on its stable isotopic composition at Roorkee,India 
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下载免费PDF全文 Ground level vapour (GLV) samples were collected at Roorkee, Uttarakhand, India using two methods: liquid condensation (LC) at 0 °C and cryogenic trap (CT) at ?78 °C for the period 2009–2011. The study reveals that there is a considerable fluctuation in stable isotopic composition of GLV throughout the year. The study area receives complex moisture source during different seasons, which is evident from the moisture flux received during different seasons. The isotopic composition of the GLV in both methods shows depleted nature during rainout process. CT method shows exact isotopic signature of GLV because of maximum trapping of air moisture and its condensation, whereas LC method shows depleted or enriched character because of the prevalence of kinetic and diffusive fractionation. The d value shows that LC method acts as magnifier of the CT method and clearly shows seasonal effect than the clustered CT method. Hence, to decipher the original isotopic signature of GLV, isotopic composition of GLVLC can be converted to GLVCT by deriving an empirical relationship with changing season and locations. Meteorological parameters show varied behaviour with GLVCT and LC because of moisture sources in all seasons. The GLVCT and LC method shows significant correlation with meteorological parameters when the region is dominated by single moisture source. The GLVLC method magnifies the correlation with meteorological parameters when the region is influenced by more than one source. The study shows that the GLVLC methods can be used in place of GLVCT when the objective is to understand the influence of different moisture sources on GLV. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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余卫平 《CT理论与应用研究》2018,27(5):659-665
目的:分析64层螺旋CT与DSA在评估冠状动脉支架置入术后通畅性及狭窄程度的价值。方法:选取2013年1月至2018年4月间我院收治的50例冠状动脉支架置入术治疗的急性冠状动脉综合征复查患者作为本研究对象;采用64层螺旋CT与DSA对急性冠状动脉综合征患者冠状动脉支架置入术后通畅性及狭窄程度进行评估,分析两者的评估价值。结果:采用64层螺旋CT及DSA检查手段对不同部位支架冠状动脉成像评分结果无明显差异P>0.05）;采用64层螺旋CT及DSA检查手段对不同直径支架冠状动脉成像评分结果无明显差异P>0.05）;采用64层螺旋CT及DSA检查手段对不同材料支架冠状动脉成像评分结果无明显差异P>0.05）;52例患者共置入96枚支架,患者均采用64层螺旋CT及DSA进行检查,结果显示64层螺旋CT及DSA检查差异无统计学意义P>0.05）。结论:对急性冠状动脉综合征患者冠状动脉支架置入术后通畅性及狭窄程度采用64排螺旋CT冠脉成像进行评估时与DSA评估结果高度一致。 相似文献
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目的:通过对比单纯超声心动图和超声心动图联合64排CT心血管造影对肺动脉狭窄部位的诊断准确性,对肺动脉主干、左、右肺动脉内径、右心室流出道内径以及患儿肺血管发育情况的预测准确率,并通过相关性分析说明超声心动图和64排CT心血管造影两种方法对左右心室各指标测量结果的密切相关性,从而阐明联合应用两种方法在提高法洛四联症心血管成像诊断准确率中的重要意义。方法:分别采用超声心动图和超声心动图联合64排CT心血管造影诊断肺动脉狭窄部位以及评价患儿肺血管发育情况,并与手术后实际诊断结果比较;采用超声心动图和超声心动图联合64排CT心血管造影测量肺动脉主干、左、右肺动脉内径以及右心室流出道内径,并与手术后实际测得结果比较;相关性分析说明超声心动图和64排CT心血管造影两种方法对左右心室各指标测量结果的相关情况。结果:超声心动图联合64排CT心血管造影诊断肺动脉狭窄部位的准确率为91.5%,明显高于单纯超声心动图的准确率68.1%(P<0.05);联合诊断组所测得Me Goon指数、Nakata指数、肺动脉主干、左、右肺动脉内径以及右心室流出道内径与手术组实测结果间无明显统计学差异(P>0.05),而超声心动图与手术实测结果相比有明显统计学差异(P<0.05);超声心动图和64排CT心血管造影对左右心室各指标测量结果均呈现密切相关性(r>0.7,P<0.05)。结论:单纯超声心动图和64排CT心血管造影在诊断法洛四联症病变方面呈现密切相关性,但超声心动图联合64排CT心血管造影对法洛四联症(TOF)病变情况的诊断准确率明显高于单纯超声心动图,为临床上法洛四联症心血管成像提供了新的思路。 相似文献
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目的:通过对320排、64排CTA以及DSA诊断颅内动脉瘤的原理和应用进行比较研究,达到选择最合适检查方法的目的。方法:收集86例颅内动脉瘤患者分别釆用320排CTA、64排CTA和3D DSA检查,研究并比较CTA和DSA影像特点。结果:86例动脉瘤患者经320排CTA诊断动脉瘤92个,64排CTA诊断90个,3D DSA诊断96个,以X2检查比较,所得数据均釆用SPSS16.0统计学软件处理,P>0.05无明显统计学差异。结论:320排CTA、64排CTA和3D DSA对颅内动脉瘤诊断各有其优势。CTA可作为辅助DSA检查颅内动脉瘤的方法;320排CTA有快速、无创和准确性高等优点,对诊断颅内动脉瘤具有很高的临床价值;图像效果明显优于64排CTA,可作术后复査和随访首选;320排CTA无法取代DSA和3D RA“金标准”的地位,可能漏诊微小动脉瘤。 相似文献
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<正>1 SURVEY OF GLOBAL SEISMICITY IN 2009 A total of 20 strong earthquakes of MS≥7. 0 occurred in the world in 2009 according to the Chinese Seismic Station Network ( Table 1). The strongest earthquake was the Samoa Islands 相似文献
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目的：探讨64排螺旋CT胸痛三联检查在急性胸痛病因诊断中的临床价值。材料和方法：对65例胸痛患者行64排螺旋CT胸痛三联检查,所有患者原始数据行多平面重建（MPR）、容积再现（VR）、曲面重建（CPR）、最大密度投影（MIP）等方法分别进行冠状动脉、肺动脉、主动脉成像,由2名有经验的放射科医师进行诊断。其中22例患者行选择性冠状动脉造影检查,并与64排螺旋CT冠状动脉CTA结果相对照。结果：所有行64排螺旋CT检查的患者均可清晰显示双侧肺动脉、冠状动脉主干及其主要分支以及胸主动脉。显示肺动脉栓塞21例、冠状动脉狭窄30例、主动脉夹层8例、主动脉瘤2例、气胸1例、3例未见明显异常。结论64排螺旋CT胸痛三联检查扫描在急性胸痛病因诊断中具有较高的临床应用价值,是一种无创、准确、快速的检查方法。 相似文献
19.
Intertidal harpacticoid copepods are commonly used in eco-toxicity tests worldwide. They predominately live in mid-high shore rock pools and often experience a wide range of temperature and salinity fluctuation. Most eco-toxicity tests are conducted at fixed temperature and salinity and thus the influence of these environmental factors on chemical toxicity is largely unknown. This study investigated the combined effect of temperature and salinity on the acute toxicity of the copepod Tigriopus japonicus against two common biocides, copper (Cu) and tributyltin (TBT) using a 2 × 3 × 4 factorial design (i.e. two temperatures: 25 and 35 °C; three salinities: 15.0‰, 34.5‰ and 45.0‰; three levels of the biocide plus a control). Copper sulphate and tributyltin chloride were used as the test chemicals while distilled water and acetone were utilised as solvents for Cu and TBT respectively. 96h-LC50s of Cu and TBT were 1024 and 0.149 μg l−1 respectively (at 25 °C; 34.5‰) and, based on these results, nominal biocide concentrations of LC0 (i.e. control), LC30, LC50 and LC70 were employed. Analysis of Covariance using ‘concentration’ as the covariate and both ‘temperature’ and ‘salinity’ as fixed factors, showed a significant interaction between temperature and salinity effects for Cu, mortality increasing with temperature but decreasing with elevated salinity. A similar result was revealed for TBT. Both temperature and salinity are, therefore, important factors affecting the results of acute eco-toxicity tests using these marine copepods. We recommend that such eco-toxicity tests should be conducted at a range of environmentally realistic temperature/salinity regimes, as this will enhance the sensitivity of the test and improve the safety margin in line with the precautionary principle. 相似文献
20.
Intertidal harpacticoid copepods are commonly used in eco-toxicity tests worldwide. They predominately live in mid-high shore rock pools and often experience a wide range of temperature and salinity fluctuation. Most eco-toxicity tests are conducted at fixed temperature and salinity and thus the influence of these environmental factors on chemical toxicity is largely unknown. This study investigated the combined effect of temperature and salinity on the acute toxicity of the copepod Tigriopus japonicus against two common biocides, copper (Cu) and tributyltin (TBT) using a 2 × 3 × 4 factorial design (i.e. two temperatures: 25 and 35 °C; three salinities: 15.0‰, 34.5‰ and 45.0‰; three levels of the biocide plus a control). Copper sulphate and tributyltin chloride were used as the test chemicals while distilled water and acetone were utilised as solvents for Cu and TBT respectively. 96h-LC50s of Cu and TBT were 1024 and 0.149 μg l−1 respectively (at 25 °C; 34.5‰) and, based on these results, nominal biocide concentrations of LC0 (i.e. control), LC30, LC50 and LC70 were employed. Analysis of Covariance using ‘concentration’ as the covariate and both ‘temperature’ and ‘salinity’ as fixed factors, showed a significant interaction between temperature and salinity effects for Cu, mortality increasing with temperature but decreasing with elevated salinity. A similar result was revealed for TBT. Both temperature and salinity are, therefore, important factors affecting the results of acute eco-toxicity tests using these marine copepods. We recommend that such eco-toxicity tests should be conducted at a range of environmentally realistic temperature/salinity regimes, as this will enhance the sensitivity of the test and improve the safety margin in line with the precautionary principle. 相似文献