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DWI及ADC图在脑梗死不同期相中的诊断价值 被引量:18
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作者 刘强 秦昕东 +3 位作者 韩景娟 纪志英 李荣华 苑晶 《医学影像学杂志》 2009年第11期1386-1390,共5页
目的:研究磁共振弥散加权成像(diffusion weighted imaging,DWI)及表观弥散系数(apparent diffusion coefficient,ADC)图像对不同期相脑梗死的图像特征及诊断价值。方法:对54例脑梗死患者按发病就诊时间分为超急性期(8例)、急性期(10例... 目的:研究磁共振弥散加权成像(diffusion weighted imaging,DWI)及表观弥散系数(apparent diffusion coefficient,ADC)图像对不同期相脑梗死的图像特征及诊断价值。方法:对54例脑梗死患者按发病就诊时间分为超急性期(8例)、急性期(10例)、亚急性期(22例)和慢性期(14例)4组,对每例进行MRI的T1-FLAIR、FSE-T2WI、T2-FLAIR、DWI序列扫描检查及ADC图像重建,分别测量病灶中心和病灶对称点正常脑组织的信号强度,计算出两者的信号差作为本序列对病灶显示的对比度,并对在各序列图像上的信号差进行对比,对急性期患者在各序列图像上同一层面所显示面积进行比较。结果:对超急性期、急性期脑梗死病灶,DWI序列的信号差(对比度)明显高于其它序列(P<0.05);亚急性期的病灶,T2-FLAIR的信号差低于DWI的病灶(P<0.05),T2WI、DWI中病灶信号差类同(P>0.05),不存在序列间的相互差别;对于慢性期的病灶,T2WI序列的病灶信号差明显高于其它序列(P<0.05);对于急性期的相同层面,T2WI、T2-FLAIR、DWI显示的病灶面积类同,不存在序列间的相互差别(P>0.05)。结论:DWI能对超急性期、急性期、亚急性期的脑梗死病灶做出明确诊断,并对超急性期、急性期病灶的诊断敏感性明显高于其它序列。 展开更多
关键词 磁共振成像 弥散加权成像 表观弥散系数 脑梗死 期相
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减少部分颅脑CT灌注成像扫描期相对急性缺血性脑卒中患者脑灌注参数准确性的影响 被引量:4
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作者 马春宁 冯佩 +3 位作者 马宁 任杰 田瑶 何源青 《山东医药》 CAS 2021年第29期57-60,共4页
目的探讨减少部分颅脑CT灌注成像扫描期相对急性缺血性脑卒中(AIS)患者脑灌注参数准确性的影响。方法收集因临床疑似AIS行颅脑CT灌注成像患者54例,将原始全静脉期相扫描灌注数据(对照组)作为参照标准,分别去除原始灌注数据中40~50 s的数... 目的探讨减少部分颅脑CT灌注成像扫描期相对急性缺血性脑卒中(AIS)患者脑灌注参数准确性的影响。方法收集因临床疑似AIS行颅脑CT灌注成像患者54例,将原始全静脉期相扫描灌注数据(对照组)作为参照标准,分别去除原始灌注数据中40~50 s的数据(实验1组)、原始灌注数据28.5 s后每间隔一期的数据(实验2组),通过CT perfusion 4D软件包去卷积算法获得三组脑灌注参数,包括脑血流量(CBF)、脑血容量(CBV)、平均通过时间(MTT)。比较三组辐射剂量,采用组内相关系数(ICC)对实验组与对照组灌注参数进行组内相关分析、Bland-Altman进行一致性分析。结果实验1组辐射剂量为对照组的86.9%,实验2组辐射剂量为对照组的82.6%。实验1组MTT小于对照组(P<0.05),两组CBF、CBV比较差异无统计学意义;实验2组CBF大于对照组、MTT小于对照组(P均<0.05),两组CBV比较差异无统计学意义。实验1组、实验2组与对照组各灌注参数组内相关性均较强(ICC均>0.6);除实验2组与对照组CBF的Bland-Altman一致性欠佳,实验组其余各参数与对照组Bland-Altman一致性均较好。结论减少灌注40~50 s扫描期像的方案降低了辐射计量,且与全静脉期相扫描在脑灌注参数的相关性和一致性上不存在明显差异,有较高准确性。 展开更多
关键词 急性缺血性脑卒中 颅脑CT灌注成像 辐射剂量 扫描期相 脑灌注参数
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单、双期CT增强甲状腺结节诊断价值比较 被引量:2
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作者 张海涛 柏劲松 +5 位作者 舒圣婕 张驰 朱倩 黄景怡 王海涛 肖康 《分子影像学杂志》 2024年第1期78-82,共5页
目的 比较单、双期CT增强对甲状腺结节的诊断价值,探索最佳扫描方案。方法 按纳入及排除标准,选取我院2020年1月~2022年6月因甲状腺结节行平扫及双期CT增强的153个病例,共171枚结节,单期CT增强组取延迟50 s的图像序列作诊断,双期CT增强... 目的 比较单、双期CT增强对甲状腺结节的诊断价值,探索最佳扫描方案。方法 按纳入及排除标准,选取我院2020年1月~2022年6月因甲状腺结节行平扫及双期CT增强的153个病例,共171枚结节,单期CT增强组取延迟50 s的图像序列作诊断,双期CT增强组取延迟25 s和50 s两组图像序列作诊断。主要评价指标为甲状腺结节良恶性诊断的准确率、结节特征的显示率、阳性淋巴结的显示率及结节的强化特点。结果 单、双期CT增强对甲状腺结节良恶性的诊断准确率差异无统计学意义(P=0.152),对甲状腺结节的边缘、形态、包膜、密度、钙化、淋巴结等特征的显示差异均无统计学意义(P>0.05)。不同密度的良恶性的甲状腺结节在两组间差异无统计学意义(P=0.418)。双期CT增强的强化方式在良恶性甲状腺结节之间差异无统计学意义(P=0.075)。结论 单、双期CT增强对甲状腺结节的诊断价值无明显差异,单期CT增强辐射剂量低,适合临床推广和应用。 展开更多
关键词 甲状腺结节 CT增强期相 诊断价值 计算机体层成像
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2π-periodic Solution for a Kind High Order Delay Duffing Equation 被引量:4
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作者 LIN Wen-xian 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2006年第1期85-89,共5页
In this paper, the high order delay Duffing equation ax^(2n) +bx+g(x(t-r)) = p(t) are considered,using the theory of coincidence degree, the sufficient condition for its there being at least a 2π-periodic s... In this paper, the high order delay Duffing equation ax^(2n) +bx+g(x(t-r)) = p(t) are considered,using the theory of coincidence degree, the sufficient condition for its there being at least a 2π-periodic solution is obtained. 展开更多
关键词 Duffing equation periodic solution coincidence degree
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Digital AGC Based on Coherent Adjustment Cycle for DSSS Receiver 被引量:4
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作者 SHEN Yuyao WANG Yongqing +1 位作者 SHENG Dewei WU Siliang 《China Communications》 SCIE CSCD 2015年第2期95-106,共12页
In order to meet the requirements for zero value stability of direct sequence spread spectrum(DSSS) signal processing in high dynamic scenario,digital automatic gain control(AGC) is employed to regulate power.However,... In order to meet the requirements for zero value stability of direct sequence spread spectrum(DSSS) signal processing in high dynamic scenario,digital automatic gain control(AGC) is employed to regulate power.However,conventional AGC causes degradation in the synchronization performance of DSSS receiver.Based on the theoretical analysis of the influence of digital AGC on DSSS signal synchronization,this paper proposes a new AGC algorithm,which is applicable to multi-channel digital DSSS signal receiver.By making power adjustment cycle and synchronization cycle coherent with each other adaptively,the influence of digital AGC on subsequent synchronization processing has been eliminated.Theoretical analysis,simulation results and experimental data verify the validity of the proposed algorithm.By virtue of the proposed algorithm,the influence of digital AGC on DSSS signal synchronization is eliminated.This algorithm applies to an aerospace engineering project successfully. 展开更多
关键词 DSSS receiver digital AGC acquisition tracking
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Multiple Positive Solutions for Some Neutral Integral Equatious Modeling Infectious Disease 被引量:1
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作者 ZHAOHua-xiang SUNXing-wang 《Chinese Quarterly Journal of Mathematics》 CSCD 2003年第1期21-28,共8页
By using fixed point index theory of cone mapping and extension method, this paper discusses the existence of multiple positive solution of nonlinear neutral integral equatious modeling infectious disease.
关键词 neutral integral equation strict set contraction CONE
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Prognostic Impact of Cell Division Cycle Associated 2 Expression on Pancreatic Ductal Adenocarcinoma 被引量:2
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作者 Meng-yi Wang Zhe-yu Niu +3 位作者 Xiang-Gao Li Zhou Quan Liao Yu-pei Zhao 《Chinese Medical Sciences Journal》 CAS CSCD 2016年第3期149-154,共6页
Objective To examine the expression of cell division cycle associated 2(CDCA 2) in pancreatic ductal adenocarcinoma(PDAC) and investigate its role in prognosis of PDAC patients.Methods This retrospective study include... Objective To examine the expression of cell division cycle associated 2(CDCA 2) in pancreatic ductal adenocarcinoma(PDAC) and investigate its role in prognosis of PDAC patients.Methods This retrospective study included 155 PDAC patients who underwent surgical treatment and complete post-operative follow-up.Clinicopathologic data were collected through clinical database.Tissue microarray was constructed and immunohistochemistry was performed to detect CDCA2 expression in the PDAC tumor tissues and adjacent non-tumor tissues.Clinicopathological characteristics between high and low CDCA2 expression were compared.Correlation of CDCA2 expressions with patients' survival was analyzed using Kaplan-Meier method and Cox regression analysis.Results Expression of CDCA2 in PDAC cells was significantly higher than that in adjacent non-tumor tissues(U=4056.5,P<0.001).Univariate analysis showed that CDCA2 expression [hazard ratio(HR)=1.574,95% confidence interval(CI)=1.014-2.443,P=0.043] and node metastasis(HR=1.704,95%CI=1.183-2.454,P=0.004) were significantly associated with prognosis.Cox regression analysis showed CDCA2 expression was not an independent prognostic risk factor(HR=1.418,95%CI=0.897-2.242,P=0.135) for PDCA patients.Stratification survival analysis demonstrated CDCA2 expression as an independent prognostic risk factor in male patients(HR=2.554,95%CI=1.446-4.511,P=0.003) or in non-perineural invasion patients(HR=2.290,95%CI=1.146-4.577,P=0.012).Conclusions CDCA2 is highly expressed in PDAC tumor tissue.Although CDCA2 is not an independent prognostic risk factor for PDAC patients,it might be used to help predict prognosis of male or non-perineural invasion patients of PDAC. 展开更多
关键词 cell division cycle associated 2 IMMUNOHISTOCHEMISTRY PROGNOSIS pancreatic ductal adenocarcinoma
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Age-related increase of early afterdepolarization in calsequestrin-2 knock-in mouse cardiomycyte 被引量:1
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作者 Yun-Feng Lan Yi Wen +8 位作者 Zhou Fang Jin-Lao Gao Yan Liu Men Lin Hong-Juan Wang Yi-Cheng Fu Prori S.G Carlo. Napolitano C Yang Li 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2010年第3期171-175,共5页
Objective To characterize early afterdepolarizations (EADs) caused triggered activity (TA) among calsequestrin-2 (CASQ2) knock-in (CASQ2 KI) mice and its relationship with aging. Methods Electrophysiological p... Objective To characterize early afterdepolarizations (EADs) caused triggered activity (TA) among calsequestrin-2 (CASQ2) knock-in (CASQ2 KI) mice and its relationship with aging. Methods Electrophysiological properties of ventricular myocytes from 3- month (mo, young), 9-mo (adult-l) and 12-too (adult-2) in wild-type (WT) and CASQ2 KI mice were investigated with patch-clamp technique. Results The incidences of EADs and TA in CASQ2 KI cardiomyocytes increased with increasing age. In contrast, WT mice cardiomyocytes showed no significant change in matched-age groups. Compared with that in 3-mo CASQ2 KI mice, the 50% repolarization of action potential (APD50) showed prolongation in both 9-mo and 12-mo ones (9.2±0.9 ms of 9-mo and 10.3 ± 1.2 ms of 12- mo vs. 5.6± 0.3 ms of 3-mo), while the 90 % repolarization of action potential (APD90) was similar among 3 age groups. Compared with 3-mo mice, the 9-mo and 12-mo CASQ2 KI mice showed markedly reduced transient outward potassium current (Ito) densities but increased L-type calcium current (ICa-L) densities. Conlcusion This study suggested that events of EADs and TA in CASQ2 KI mice increased with increasing age, It might be associated partly with the augment of cellular calcium concentration and the prolongation of APD50 induced by decrease of Ito and increase of ICa-L in adult CASQ2 KI mice 展开更多
关键词 CALSEQUESTRIN early afterdepolarization triggered activity gene mutation transgenic mice
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New Periodic Wave Solutions and Their Interaction for (2+1)-dimensional KdV Equation
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作者 GE Dong-jie MA Hong-cai YU Yao-dong 《Chinese Quarterly Journal of Mathematics》 CSCD 2009年第4期525-536,共12页
A class of new doubly periodic wave solutions for (2+1)-dimensional KdV equation are obtained by introducing appropriate Jacobi elliptic functions and Weierstrass elliptic functions in the general solution(contain... A class of new doubly periodic wave solutions for (2+1)-dimensional KdV equation are obtained by introducing appropriate Jacobi elliptic functions and Weierstrass elliptic functions in the general solution(contains two arbitrary functions) got by means of multilinear variable separation approach for (2+1)-dimensional KdV equation. Limiting cases are considered and some localized excitations are derived, such as dromion, multidromions, dromion-antidromion, multidromions-antidromions, and so on. Some solutions of the dromion-antidromion and multidromions-antidromions are periodic in one direction but localized in the other direction. The interaction properties of these solutions, which are numerically studied, reveal that some of them are nonelastic and some are completely elastic. Furthermore, these results are visualized. 展开更多
关键词 (2+1)-dimensional KdV equation multilinear variable separation approach elliptic functions periodic wave solutions localized excitations interaction property nonelastic completely elastic
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Memory Function and Fractional Intergral Associated to the Random Self-similar Fractal 被引量:1
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作者 LIANG Hong-liang,LIU Xiao-shu(Department of Mathematics, Shangqiu Teacher’s College, Shangqiu 476000, China) 《Chinese Quarterly Journal of Mathematics》 CSCD 2003年第2期186-191,共6页
For a physics system which exhibits memory,if memory is preserved only at points of random self-similar fractals,we define random memory functions and give the connection between the expectation of flux and the fracti... For a physics system which exhibits memory,if memory is preserved only at points of random self-similar fractals,we define random memory functions and give the connection between the expectation of flux and the fractional integral.In particular,when memory sets degenerate to Cantor type fractals or non-random self-similar fractals our results coincide with that of Nigmatullin and Ren et al. 展开更多
关键词 random self-similar fractals memory functions memory measures Laplace transform
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