共查询到20条相似文献，搜索用时 78 毫秒
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目的:探讨多排螺旋CT（MDCT）在术前胃癌T分期中的应用价值。方法:收集胃癌616例患者,行MDCT术前T分期,与术后病理T分期（pT）对照,用卡方检验分析MDCT T分期准确性与临床-病理学因素相关性。结果:MDCT胃癌T分期总准确度为91%（560/616）,其中pT195%（377/396）,pT2-3 78%（80/103）,pT4a 89%（97/109）,pT4b 75%（6/8）。BorrmannⅠ型（P=0.0001）与位于胃窦（P=0.045）或影响MDCT T分期准确性,年龄、性别、肿瘤位于大弯或小弯、肿瘤分化不影响其准确性。结果:MDCT在胃癌术前T分期方面有较高的应用价值。 相似文献
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目的:评估磁共振二维T2加权自旋回波成像序列(2D-T2WI TSE)与三维T2加权自旋回波成像序列(3D-T2WI TSE,VISTA)两种成像方法在直肠癌术前分期的准确性。方法:采用飞利浦3.0T MR机扫描,由两位放射科医师独立评估,回顾性分析从2016年1月至2016年4月间经病理确诊的33例直肠癌患者的2D-MRI序列及3D VISTA扫描序列图像。运用SPSS统计软件分别分析2D序列及3D VISTA序列对直肠癌术前T、N分期的准确性,并检验诊断结果的一致性。结果:33例病例,医师1与医师2其常规2D和3D VISTA检查序列T分期的准确性分别为70%和85%(P=0.274)及73%和82%(P=0.454),Kappa分别为0.576和0.790及0.618和0.746,3D VISTA序列评估T分期与病理结果的一致性优于2D序列;其N分期的准确性分别为58%和70%(P=0.182)及58%和67%(P=0.218),Kappa分别为0.252和0.407及0.267和0.376,N分期2D及3D VISTA分期与病理结果的一致性较差。结论:2D与3D VISTA序列对直肠癌TN分期的准确性无统计学差异,但是3D VISTA较2D序列在鉴别T2与早期T3及N分期方面有一定潜在优势。 相似文献
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MSCT和X线平片在诊断腰椎滑脱症中的临床价值比较 总被引：3，自引：1，他引：2
目的:比较X线平片和多排螺旋CT诊断腰椎滑脱的准确性,并评价临床价值。方法:搜集40例经X线平片、MSCT检查诊断并手术治疗的腰椎滑脱患者,X线平片和MSCT判定腰椎滑脱程度、部位、类型的结果与手术对照。结果:40例患者,27例手术证实为真性滑脱,13例为假性滑脱。以手术为对照,X线平片、MSCT诊断腰椎滑脱程度和部位准确率为100%;X线平片判定腰椎滑脱类型的敏感性、特异性、阳性和阴性预测值为分别为59.3%、100%、100%和54.2%;MSCT判定滑脱类型的敏感性、特异性、阳性和阴性预测值均为100%;X线平片和MSCT对滑脱类型判定具有明显统计学差异(P0.01)。结论:X线平片、MSCT判定腰椎滑脱程度和部位均具有较高的准确性;判定腰椎滑脱类型,MSCT比X线平片好,X线平片目前仍是基本的筛查方法,MSCT进一步明确腰椎滑脱类型诊断,为临床提供更多的影像信息和治疗方案。 相似文献
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目的:探讨胸部多层螺旋CT（MSCT）对乳腺肿块的诊断价值。方法:收集经手术病理证实的72例乳腺肿块患者的术前胸部MSCT及乳腺X线摄影的影像学资料，包括乳腺恶性肿块54例，良性肿块18例。根据患者乳腺腺体类型分为非致密型组（23例）、致密型组（49例）。以病理检查结果为参考，评价胸部MSCT检查及乳腺X线摄影对不同腺体类型乳腺肿块的诊断效能。结果:致密型乳腺组，胸部MSCT对恶性肿块诊断准确率为89.19%，高于乳腺X线摄影的67.57%，差异有统计学意义（P=0.024，χ2=5.103）；胸部MSCT对良性肿块诊断准确率为75%，高于乳腺X线摄影的58.33%。非致密型乳腺组，乳腺X线摄影对恶性肿块诊断准确率94.12%，略高于胸部MSCT 82.35%。胸部MSCT、乳腺X线摄影对全部乳腺肿块诊断准确率分别为86.11%和75%。胸部MSCT对转移性淋巴结及胸部转移灶的检出率优于乳腺X线摄影。结论:胸部MSCT对乳腺肿块的定性诊断具有较高价值。胸部MSCT对致密型乳腺中肿块的诊断较乳腺X线摄影可提供更多信息、提高诊断准确率。 相似文献
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目的:采用高分辨率小FOV双重造影结合DWI扫描技术,探讨磁共振成像(MRI)对直肠癌术前分期的意义。方法:收集2013年1月至2016年1月直肠癌的病例250例,综合所有序列对直肠癌病灶进行术前MRI-TN分期,评估直肠系膜筋膜和环周切缘是否累及,并与手术病理结果进行对照分析。结果:MRI T分期准确率为88.8%(222/250),MRI诊断直肠癌各T分期的准确率、敏感性、特异性、阳性预测值及阴性预测值与术后病理T分期的一致性较好,Kappa值=0.712,P=0.000。N分期准确率为75.6%(189/250),MRI诊断各N分期的准确率、敏感性、特异性、阳性预测值及阴性预测值,与术后病理的一致性为中度一致,Kappa值=0.623,P=0.000。环周切缘准确率为97.6%(58/52)。敏感性100%、特异性97.0%、阳性预测值及阴性预测值分别为89.7%、100%。结论:1薄层、小FOV高分辨率MRI双重造影结合DWI可以多参数、多角度对直肠癌术前T分期做出准确的分期,对N分期做出较准确分期。2 MRI可以对环周切缘有无累及进行准确的预测。3矢状位能准确测量肿瘤下缘距肛缘的距离,为术前评估是否保肛提供直观信息。 相似文献
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目的:研究并分析双源双能量CT碘值测定在胃癌术前T分期诊断中的价值。方法:选取2015年1月～2017年12月在我院进行双源双能量CT检查,且经手术病理证实为T分期的110例胃癌患者为研究对象,计算T1和T2-3期下动脉期和静脉期在胃壁内层、外层以及正常胃壁的标准化碘浓度（NIC）,并40keV、60keV以及120keV时的图像质量客观指标和主观指标。结果:T分期下动、静脉期的胃壁内层与外层和正常胃壁碘基值均有统计学差异（P<0.05）。T分期下动静脉期的胃壁外层与正常胃壁的碘基值均无统计学差异（P>0.05）。120keV组的CT值、图像噪声、SNR及CNR图像质量客观指标均低于60keV组和40keV组（P<0.05）。60keV组的图像质量客观指标均低于40keV组（P<0.05）。60keV组的总体图像质量评分高于40keV组和120keV组（P<0.05）。三组在病灶显著性评分无统计学差异（P>0.05）。结论:采用双源双能量CT碘值测定方式,对于鉴别诊断T1和T2-3期胃癌具有显著价值,且能够提高图像的质量,对于增强胃癌术前T分期的准确率有重要意义。 相似文献
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16层螺旋CT与钡灌肠在结直肠癌诊断的对比研究 总被引：1，自引：0，他引：1
目的:探讨16层螺旋CT在中晚期结直肠癌诊断中的应用价值.材料与方法:对35例经病理证实的结直肠癌病人进行回顾性分析.通过MS-CTC检查进行术前Duke's分期,并与手术病理分期对照分析.结果:BE检查32例,BE对结直肠病变的敏感度为97.5%,准确度为84.4%;MS-CTC检查35例,MS-CTC对结直肠病变的敏感度为100%,准确度为91.4%.MS-CTC对Duke's分期诊断准确度率为85.7%.结论:BE是结直肠癌的常规影像学检查方法,MS-CTC检查能够提供多方面的诊断信息,对结直肠癌的诊断及术前分期都有重要价值. 相似文献
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目的:分析多层螺旋CT（MSCT）对胃间质瘤（GST）诊断及临床治疗指导价值。方法:收集本院2018年1月至2019年2月收治的56例胃间质瘤患者的临床资料，收集患者临床资料对患者进行病理危险度评估，分析不同病理危险度患者的MSCT图像表现差异，计算MSCT对GST的诊断准确率。结果:56例患者中病理危险度极低者11例（19.64%），危险度低者18例（32.14%），中危险度者14例（25.00%），高危险度者13例（23.21%）。MSCT平扫密度、瘤内有无坏死/溃疡、动静脉其强化程度差值、瘤内及瘤周有无血管与病理危险度比较差异无统计学意义（P>0.05）；瘤周脂肪间隙、强化方式与病理危险度比较有明显差异（P<0.05）；以病理活检为对照，MSCT对GST的诊断准确例数为53例，诊断准确率为94.64%，其中3例误诊为胃癌，误诊率为5.45%。结论:MSCT对GST诊断准确率高，可有效显示不同病理危险度GST图像表现特点，为临床手术提供可靠影像学信息。 相似文献
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陈悦熙 《CT理论与应用研究》2021,30(6):761-767
目的:探讨多排螺旋CT（MSCT）对胰腺癌胰外神经浸润的诊断价值。方法:比较实验组20例胰腺癌患者及对照组50例健康人腹腔神经节的形态、大小及各期CT值变化。以病理结果为标准,分析MSCT对腹腔神经节侵犯的准确性、特异性和敏感性。结果:实验组腹腔神经节形态为粗条形,周围脂肪间隙不清;对照组腹腔神经节形态为细条形或小结节形,周围脂肪间隙清晰。实验组双侧腹腔神经节长径、短径均大于对照组,实验组左侧腹腔神经节3期扫描CT值均大于对照组。与病理结果比较,CT对胰腺癌腹腔神经节侵犯诊断的敏感性、特异性、准确性分别为80%、60%和75%。结论:MSCT对胰外神经浸润具有较高诊断价值,能清晰显示腹腔神经节的形态、大小及CT值变化,当出现腹腔神经节呈粗条形增大、脂肪间隙不清及明显强化时,提示已有肿瘤的神经侵犯。 相似文献
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目的:探讨T2WI 3D-SPACE联合EPI DWI成像技术在直肠癌术前评估中的应用价值。方法:回顾性收集2018年1月1日至2019年8月30日于我院行直肠磁共振（MR）扫描的直肠癌患者36例纳入本组研究,扫描三方位高分辨T2WI序列、T2WI 3D-SPACE序列、EPI DWI序列。分别计算高分辨T2WI序列联合EPI DWI序列（A组）、T2WI 3D-SPACE序列联合EPI DWI序列（B组）对直肠癌T分期的敏感性、特异性及准确性,并采用McNemar检验比较两组序列总的T分期准确性有无显著性差异。结果:两组序列分别与术后病理结果对照,B组序列T1、T2期准确性稍高于A组序列,两组序列总的T分期准确性分别为68.75%和71.88%,差异无统计学意义（P>0.05）。结论:T2WI 3D-SPACE序列联合EPI DWI序列对直肠癌T分期的准确率与高分辨T2WI序列联合EPI DWI序列相比无统计学差异,可作为直肠癌MRI常规术前评估序列。 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
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