期刊文献+
共找到2,460篇文章
< 1 2 123 >
每页显示 20 50 100
Magnetic resonance imaging techniques for lithium-ion batteries:Principles and applications
1
作者 Hongxin Lin Yanting Jin +4 位作者 Mingming Tao Yingao Zhou Peizhao Shan Danhui Zhao Yong Yang 《Magnetic Resonance Letters》 2024年第2期22-39,共18页
Operando monitoring of internal and local electrochemical processes within lithium-ion batteries(LIBs)is crucial,necessitating a range of non-invasive,real-time imaging characterization techniques including nuclear ma... Operando monitoring of internal and local electrochemical processes within lithium-ion batteries(LIBs)is crucial,necessitating a range of non-invasive,real-time imaging characterization techniques including nuclear magnetic resonance(NMR)techniques.This review provides a comprehensive overview of the recent applications and advancements of non-invasive magnetic resonance imaging(MRI)techniques in LIBs.It initially introduces the principles and hardware of MRI,followed by a detailed summary and comparison of MRI techniques used for characterizing liquid/solid electrolytes,electrodes and commercial batteries.This encompasses the determination of electrolytes'transport properties,acquisition of ion distribution profile,and diagnosis of battery defects.By focusing on experimental parameters and optimization strategies,our goal is to explore MRI methods suitable to a variety of research subjects,aiming to enhance imaging quality across diverse scenarios and offer critical physical/chemical insights into the ongoing operation processes of LIBs. 展开更多
关键词 Lithium-ion batteries magnetic resonance imaging(mri) Electrolytes ELECTRODES Commercial batteries
下载PDF
Reduced Imaging Time and Improved Image Quality of 3D Isotropic T2-Weighted Magnetic Resonance Imaging with Compressed Sensing for the Female Pelvis
2
作者 Hao Mei Feng Xiao Ming Deng 《Journal of Beijing Institute of Technology》 EI CAS 2023年第5期579-585,共7页
This study is to compare three-dimensional(3D)isotropic T2-weighted magnetic resonance imaging(MRI)with compressed sensing-sampling perfection with application optimized contrast(CS-SPACE)and the conventional image(3D... This study is to compare three-dimensional(3D)isotropic T2-weighted magnetic resonance imaging(MRI)with compressed sensing-sampling perfection with application optimized contrast(CS-SPACE)and the conventional image(3D-SPACE)sequence in terms of image quality,estimated signal-to-noise ratio(SNR),relative contrast-to-noise ratio(CNR),and the lesions’conspicuous of the female pelvis.Thirty-six females(age:51,28-73)with cervical carcinoma(n=20),rectal carcinoma(n=7),or uterine fibroid(n=9)were included.Patients underwent magnetic resonance(MR)imaging at a 3T scanner with the sequences of 3D-SPACE,CS-SPACE,and twodimensional(2D)T2-weighted turbo-spin echo(TSE).Quantitative analyses of estimated SNR and relative CNR between tumors and other tissues,image quality,and tissue conspicuity were performed.Two radiologists assessed the difference in diagnostic findings for carcinoma.Quantitative values and qualitative scores were analyzed,respectively.The estimated SNR and the relative CNR of tumor-to-muscle obturator internus,tumor-to-myometrium,and myometrium-to-muscle obturator internus was comparable between 3D-SPACE and CS-SPACE.The overall image quality and the conspicuity of the lesion scores of the CS-SPACE were higher than that of the 3D-SPACE(P<0.01).The CS-SPACE sequence offers shorter scan time,fewer artifacts,and comparable SNR and CNR to conventional 3D-SPACE,and has the potential to improve the performance of T2-weighted images. 展开更多
关键词 compressed sensing sampling perfection with application-oriented contrasts(SPACE)using variable flip angle evolutions three-dimensional(3D)imaging magnetic resonance imaging(mri) PELVIS
下载PDF
Role of pulmonary perfusion magnetic resonance imaging for the diagnosis of pulmonary hypertension:A review
3
作者 Miriam Lacharie Adriana Villa +3 位作者 Xenios Milidonis Hadeer Hasaneen Amedeo Chiribiri Giulia Benedetti 《World Journal of Radiology》 2023年第9期256-273,共18页
Among five types of pulmonary hypertension,chronic thromboembolic pulmonary hypertension(CTEPH)is the only curable form,but prompt and accurate diagnosis can be challenging.Computed tomography and nuclear medicine-bas... Among five types of pulmonary hypertension,chronic thromboembolic pulmonary hypertension(CTEPH)is the only curable form,but prompt and accurate diagnosis can be challenging.Computed tomography and nuclear medicine-based techniques are standard imaging modalities to non-invasively diagnose CTEPH,however these are limited by radiation exposure,subjective qualitative bias,and lack of cardiac functional assessment.This review aims to assess the methodology,diagnostic accuracy of pulmonary perfusion imaging in the current literature and discuss its advantages,limitations and future research scope. 展开更多
关键词 Pulmonary perfusion mri Pulmonary hypertension Dynamic contrast enhanced magnetic resonance imaging Chronic thromboembolic pulmonary hypertension Computed tomography pulmonary angiography Chronic thromboembolic disease
下载PDF
Magnetic resonance imaging ancillary features used in Liver Imaging Reporting and Data System:An illustrative review 被引量:3
4
作者 David Campos-Correia Joao Cruz +2 位作者 António P Matos Filipa Figueiredo Miguel Ramalho 《World Journal of Radiology》 CAS 2018年第2期9-23,共15页
Hepatocellular carcinoma (HCC) usually develops in the setting of chronic liver disease. In the adequate clinical context, both multiphasic contrast-enhanced CT and magnetic resonance imaging are non-invasive modaliti... Hepatocellular carcinoma (HCC) usually develops in the setting of chronic liver disease. In the adequate clinical context, both multiphasic contrast-enhanced CT and magnetic resonance imaging are non-invasive modalities that allow accurate diagnosis and staging of HCC, although the latter demonstrates greater sensitivity and specificity. Imaging criteria for HCC diagnosis rely on hemodynamic features such as hyperenhancement in the arterial phase and washout in the portal or equilibrium phase. However, imaging performance drops considerably for small (< 20 mm) nodules because their tendency to exhibit atypical enhancement patterns. In order to improve accuracy in the diagnosis and staging of HCC, particularly in cases of atypical nodules, ancillary features, i.e., imaging characteristics that modify the likelihood of HCC, have been described and incorporated into clinical reports, especially in Liver Imaging Reporting and Data System. In this paper, ancillary imaging features will be reviewed and illustrated. 展开更多
关键词 HEPATOCELLULAR carcinoma Ancillary FEATURES magnetic resonance imaging LIVER imaging REPORTING and data System CIRRHOSIS LIVER
下载PDF
Application of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)combined with magnetic resonance spectroscopy(MRS)in prostate cancer diagnosis 被引量:1
5
作者 Yakun He Min Wang +1 位作者 Heping Deng Jin Ren 《Oncology and Translational Medicine》 CAS 2021年第1期31-34,共4页
Objective The aim of the study was to investigate the application of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)combined with magnetic resonance spectroscopy(MRS)in prostate cancer diagnosis.Methods ... Objective The aim of the study was to investigate the application of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)combined with magnetic resonance spectroscopy(MRS)in prostate cancer diagnosis.Methods In the outpatient department of our hospital(Sichuan Cancer Hospital,Chengdu,China),60 patients diagnosed with prostate disease were selected randomly and included in a prostate cancer group,60 patients with benign prostatic hyperplasia were included in a proliferation group,and 60 healthy subjects were included in a control group,from January 2013 to January 2017.Using Siemens Avanto 1.5 T high-field superconducting MRI for DCE-MRI and MRS scans,after the MRS scan was completed,we used the workstation spectroscopy tab spectral analysis,and eventually obtained the crest lines of the prostate metabolites choline(Cho),creatine(Cr),citrate(Cit),and the values of Cho/Cit,and(Cho+Cr)/Cit.Results Participants who had undergone 21-s,1-min,and 2-min dynamic contrast-enhanced MR revealed significant variations among the three groups.The spectral analysis of the three groups revealed a significant variation as well.DCE-MRI and MRS combined had a sensitivity of 89.67%,specificity of 95.78%,and accuracy of 94.34%.Conclusion DCE-MRI combined with MRS is of great value in the diagnosis of prostate cancer. 展开更多
关键词 prostate cancer magnetic resonance imaging(mri) dynamic contrast-enhanced(DCE) spectroscopy
下载PDF
Generalized Nonconvex Low-Rank Algorithm for Magnetic Resonance Imaging (MRI) Reconstruction
6
作者 吴新峰 刘且根 +2 位作者 卢红阳 龙承志 王玉皞 《Journal of Donghua University(English Edition)》 EI CAS 2017年第2期316-321,共6页
In recent years,utilizing the low-rank prior information to construct a signal from a small amount of measures has attracted much attention.In this paper,a generalized nonconvex low-rank(GNLR) algorithm for magnetic r... In recent years,utilizing the low-rank prior information to construct a signal from a small amount of measures has attracted much attention.In this paper,a generalized nonconvex low-rank(GNLR) algorithm for magnetic resonance imaging(MRI)reconstruction is proposed,which reconstructs the image from highly under-sampled k-space data.In the algorithm,the nonconvex surrogate function replacing the conventional nuclear norm is utilized to enhance the low-rank property inherent in the reconstructed image.An alternative direction multiplier method(ADMM) is applied to solving the resulting non-convex model.Extensive experimental results have demonstrated that the proposed method can consistently recover MRIs efficiently,and outperforms the current state-of-the-art approaches in terms of higher peak signal-to-noise ratio(PSNR) and lower high-frequency error norm(HFEN) values. 展开更多
关键词 magnetic resonance imaging(mri) low-rank approximation nonconvex optimization alternative direction multiplier method(ADMM)
下载PDF
Obstacles Facing the Implementation of Functional Magnetic Resonance Imaging (fMRI) of Brain in Jeddah City
7
作者 Abrar Mohammed Shafia M. Noor Hanan Mohammed Alzahrani Zuber Ahmed 《Computer Technology and Application》 2013年第2期123-126,共4页
fMRI (Functional Magnetic Resonance Imaging) is a relatively new technique that uses MRI (Magnetic Resonance Imaging) to measure the hemodynamic response (change in blood flow) related to neural activity in the ... fMRI (Functional Magnetic Resonance Imaging) is a relatively new technique that uses MRI (Magnetic Resonance Imaging) to measure the hemodynamic response (change in blood flow) related to neural activity in the brain. This paper aims to explore and identify the obstacles facing the implementation and applications of IMRI in radiology departments within Jeddah city by analyzing related data received by direct questionnaires and interviews with all the people working in MRI units in Jeddah city and finds that the major obstacle is lacking of awareness of fMRI among medical professionals and their training. 展开更多
关键词 fmri (Functional magnetic resonance imaging brain imaging mri magnetic resonance imaging).
下载PDF
动态增强MRI定量参数及肿瘤标记物对乳腺癌新辅助化疗疗效的评估价值分析 被引量:2
8
作者 马瑞 王彦辉 +3 位作者 杜敏 齐先龙 张琳 王唯伟 《中国医学装备》 2024年第1期73-77,共5页
目的:探索动态增强磁共振成像(DCE-MRI)定量参数及肿瘤标记物对乳腺癌新辅助化疗疗效的评估价值。方法:选取2019年5月至2022年5月在济宁市第一人民医院接受新辅助化疗联合手术干预的75例乳腺癌患者,根据实体瘤疗效评价标准(RECIST)将其... 目的:探索动态增强磁共振成像(DCE-MRI)定量参数及肿瘤标记物对乳腺癌新辅助化疗疗效的评估价值。方法:选取2019年5月至2022年5月在济宁市第一人民医院接受新辅助化疗联合手术干预的75例乳腺癌患者,根据实体瘤疗效评价标准(RECIST)将其分为有效组(54例)和无效组(21例),比较化疗前和化疗后两组患者DCE-MRI定量参数血管外细胞外间隙容积比(V_(e))、速率常数(K_(ep))及容积转换常数(K^(trans))指标与肿瘤标志物癌胚抗原(CEA)、糖类抗原(CA125)及糖类抗原15-3(CA15-3)水平,采用受试者工作特征(ROC)曲线分析各项诊断方式预测效能。结果:化疗后,有效组患者DCEMRI定量参数Ve、K_(ep)及K^(trans)与无效组比较,差异有统计学意义(t=7.237、51.695、16.879,P<0.05)。有效组患者肿瘤标志物CEA、CA125及CA15-3与无效组比较,差异有统计学意义(t=44.201、6.736、6.885,P<0.05)。V_(e)、K_(ep)、K^(trans)、CEA、CA125及CA15-3的6项指标联合预测乳腺癌新辅助化疗疗效ROC曲线下面积(AUC)值为0.979,显著高于各项指标单独检测的AUC值,差异有统计学意义(Z=2.993、2.679、2.510、2.731、3.215、3.071,P<0.05)。结论:肿瘤标记物联合DCE-MRI定量参数可更好预测乳腺癌新辅助化疗疗效情况,间接评估预后。 展开更多
关键词 动态增强磁共振成像(DCE-mri) 肿瘤标记物 化疗 乳腺癌
下载PDF
基于多模态MRI定量分析诊断宫颈癌宫旁浸润的研究 被引量:1
9
作者 牛俊巧 王佳 +3 位作者 刘焱 曲源 张建亮 李辉 《中国CT和MRI杂志》 2024年第5期137-139,共3页
目的探讨多模态MRI定量分析诊断宫颈癌宫旁浸润的价值。方法回顾性分析2019年1月~2021年12月新疆维吾尔自治区人民医院收治的86例宫颈癌患者临床资料,根据病理结果分为宫旁浸润组31例与非宫旁浸润组55例。所有患者均接受MRI常规平扫及... 目的探讨多模态MRI定量分析诊断宫颈癌宫旁浸润的价值。方法回顾性分析2019年1月~2021年12月新疆维吾尔自治区人民医院收治的86例宫颈癌患者临床资料,根据病理结果分为宫旁浸润组31例与非宫旁浸润组55例。所有患者均接受MRI常规平扫及扩散加权成像(DWI)扫描、动态对比增强磁共振成像(DCE-MRI)扫描,获得感兴趣区表观弥散系数(ADC)值和对比剂容积转换常量(K^(trans))、速率常数(K_(ep))、血管外细胞间隙容积分数(V_(e))值等多模态MRI定量参数。比较宫旁浸润组和非宫旁浸润组临床特征、ADC值和DCE-MRI定量参数;Pearson相关性分析宫颈癌宫旁浸润患者ADC值和K^(trans)、K_(ep)、V_(e)的关系;受试者工作特征曲线(ROC)分析ADC值和K^(trans)、K_(ep)、V_(e)对宫颈癌宫旁浸润的诊断效能。结果宫旁浸润组与非宫旁浸润组肿瘤直径和病理分级的分布差异比较,差异有统计学意义(P<0.05);宫旁浸润组K^(trans)、K_(ep)和V_(e)均明显高于非宫旁浸润组(P<0.05);Pearson相关性显示,宫颈癌宫旁浸润患者ADC值与V_(e)值呈明显的正相关(P<0.05);ROC显示,K^(trans)、K_(ep)、V_(e)值诊断宫颈癌宫旁浸润的曲线下面积(AUC)分别为0.876、0.821和0.864(P<0.05)。结论多模态MRI定量参数对宫颈癌宫旁浸润具有较好的诊断价值,可为宫颈癌宫旁浸润的影像诊断提供量化参考。 展开更多
关键词 多模态mri 扩散加权成像 动态对比增强磁共振成像 表观弥散系数 宫颈癌 宫旁浸润
下载PDF
颈部影像报告和数据系统在MRI诊断早期单纯黏膜型鼻咽癌局部复发中的应用 被引量:1
10
作者 汪泽燕 吴磊迪 +3 位作者 钟柱 王星蕊 肖学红 王志龙 《磁共振成像》 CAS CSCD 北大核心 2024年第3期170-176,共7页
目的探讨颈部影像报告和数据系统(neck imaging reporting and data systems,NI-RADS)MRI对单纯黏膜型鼻咽癌局部复发(exclusive mucosal local recurrent nasopharyngeal carcinoma,EMLRNPC)与黏膜治疗后改变(mucosal posttreatment ch... 目的探讨颈部影像报告和数据系统(neck imaging reporting and data systems,NI-RADS)MRI对单纯黏膜型鼻咽癌局部复发(exclusive mucosal local recurrent nasopharyngeal carcinoma,EMLRNPC)与黏膜治疗后改变(mucosal posttreatment changes,MPTC)的诊断价值,尝试为NI-RADS MRI词典中的局灶性黏膜异常建议附加定性扩散加权成像(diffusion-weighted imaging,DWI)标准。材料与方法回顾性分析2015年2月至2023年2月经病理或影像随访确诊的21例EMLRNPC和29例MPTC。先由2名影像医师独立评价MRI表现,进行NI-RADS MRI分类,再进行附加定性DWI标准的改良NI-RADS MRI分类,3个月后,由其中的1名高年资影像医师再次进行分类。采用Cohen’s Kappa检验评估观察者间、观察者内NI-RADS分类一致性。绘制受试者工作特征(receiver operating characteristic,ROC)曲线评价这两种NI-RADS分类对EMLRNPC与MPTC的诊断效能,曲线下面积(area under the curve,AUC)的比较采用DeLong检验。结果NI-RADS MRI、改良NI-RADS MRI的分类观察者间与观察者内一致性为0.69与0.88、0.83与0.96。NI-RADS MRI和改良NI-RADS MRI鉴别诊断ELRNPC与MPTC的AUC、敏感度、特异度为0.845[95%置信区间(confidence interval,CI):0.715~0.932]、100.0%(95%CI:83.9%~100.0%)、69.0%(95%CI:49.2%~84.7%)和0.966(95%CI:0.871~0.997)、100.0%(95%CI:83.9%~100.0%)、93.1%(95%CI:77.2%~99.2%),两种分类的AUC间差异有统计学意义(Z=2.985,P=0.003)。结论NI-RADS MRI与附加定性DWI标准的改良NI-RADS MRI对EMLRNPC与MPTC均具有较高的鉴别诊断价值,改良NI-RADS MRI分类的诊断效能、一致性更高。 展开更多
关键词 鼻咽癌 局部肿瘤复发 磁共振成像 颈部影像报告和数据系统 扩散加权成像
下载PDF
MRI梯度波形发生器研究进展
11
作者 刘颖 林羚 +1 位作者 袁斌华 章浩伟 《波谱学杂志》 CAS 2024年第1期99-115,共17页
成像体素空间位置的准确编码对于磁共振成像(MRI)的空间定位至关重要.为了保证空间编码的准确性,获得高性能的梯度磁场是关键.梯度波形发生器是产生梯度磁场的核心部件,本文简要介绍了梯度波形发生器的工作原理和组成部分,总结了近二十... 成像体素空间位置的准确编码对于磁共振成像(MRI)的空间定位至关重要.为了保证空间编码的准确性,获得高性能的梯度磁场是关键.梯度波形发生器是产生梯度磁场的核心部件,本文简要介绍了梯度波形发生器的工作原理和组成部分,总结了近二十年来基于不同设计方案设计的梯度波形发生器的研究进展,详细探讨了梯度波形预加重的实现方法,并对梯度波形发生器未来的研究和发展方向进行了展望. 展开更多
关键词 磁共振成像 梯度波形发生器 数字信号处理器 现场可编程门阵列 预加重
下载PDF
脊椎骨内神经鞘瘤的CT、MRI表现(附11例报道及文献复习)
12
作者 刘玉 王远军 李开成 《生物医学工程学进展》 CAS 2024年第2期136-141,共6页
目的探讨脊椎骨内神经鞘瘤(Intraosseous Schwannoma,IOS)的特征性影像学表现,以与其他脊椎溶骨性病变区别开。方法回顾性分析上海交通大学医学院附属第九人民医院经手术病理证实的脊椎IOS的临床资料及CT、MRI等影像学资料。该文收集了1... 目的探讨脊椎骨内神经鞘瘤(Intraosseous Schwannoma,IOS)的特征性影像学表现,以与其他脊椎溶骨性病变区别开。方法回顾性分析上海交通大学医学院附属第九人民医院经手术病理证实的脊椎IOS的临床资料及CT、MRI等影像学资料。该文收集了11例脊椎IOS患者,其中男性7例,女性4例,年龄23~74岁[平均年龄(51±17)岁]。所有患者均行CT和MRI检查。由两名高年资骨关节系统放射科医师对所有影像学征象进行评估,并复习了近几年来文献报告的脊椎IOS影像学征象。结果病变累及部位包括颈椎3例(3/11,27.3%),胸椎1例(1/11,9.1%),腰椎5例(5/11,45.5%),腰骶椎2例(2/11,18.2%),最大径(5.8±2.85)cm,形态均为不规则形。CT显示偏心性膨胀性溶骨性骨质破坏,密度不均匀,平扫CT值为(43.0±11.55)HU。增强后不均匀轻度强化,CT值为(70.3±12.22)HU,病灶边界清晰,有硬化缘,未见骨膜反应,病灶易沿着椎间孔向椎管内外延伸。在MRI上,与肌肉组织相比,病灶在T1WI上呈等稍低信号,在T2WI上呈混杂稍高信号,压脂后呈混杂高信号,DWI未见弥散受限,ADC值为(1.25±0.176)×10-3mm2/s,增强后不均匀明显强化,时间-信号强度曲线为I型,7例患者病灶内发生囊性变。结论脊椎IOS是一种罕见的良性肿瘤,影像学表现具有一定的特征性,在鉴别诊断边界清晰的具有异质性的脊椎溶骨性病变时应予以考虑。 展开更多
关键词 骨内神经鞘瘤 脊椎 计算机断层扫描 核磁共振
下载PDF
双参数与多参数MRI对前列腺特异性抗原灰区临床显著性前列腺癌诊断效能比较
13
作者 董喆 张云 +5 位作者 王海屹 刘百川 丁效蕙 郝雨薇 徐鸿昊 叶慧义 《国际医学放射学杂志》 2024年第3期328-334,共7页
目的探讨基于前列腺影像报告与数据系统2.1版(PI-RADS v2.1)的双参数MRI(bpMRI)与多参数MRI(mpMRI)对前列腺特异性抗原(PSA)灰区(PSA 4~10 ng/mL)临床显著性前列腺癌(csPCa)的诊断效能。方法回顾性纳入2家医疗中心接受前列腺活检术并完... 目的探讨基于前列腺影像报告与数据系统2.1版(PI-RADS v2.1)的双参数MRI(bpMRI)与多参数MRI(mpMRI)对前列腺特异性抗原(PSA)灰区(PSA 4~10 ng/mL)临床显著性前列腺癌(csPCa)的诊断效能。方法回顾性纳入2家医疗中心接受前列腺活检术并完成MRI检查的PSA灰区病人270例(中心1,220例;中心2,50例),分析病人的临床及MRI影像资料。根据Gleason评分将病人分为csPCa组(177例)和非csPCa组(93例)。基于PI-RADS v2.1标准,根据bpMRI(T2WI、DWI)与mpMRI(T2WI、DWI和DCE-MRI)对每例病人的病灶进行评分。采用独立样本t检验、Mann-Whitney U检验、χ2检验比较2组病人的一般资料[年龄、PSA、前列腺体积(PV)、PSA密度(PSAD)]、bpMRI评分和mpMRI评分。以前列腺活检病理结果为标准,绘制受试者操作特征(ROC)曲线,计算其曲线下面积(AUC)、敏感度、特异度、准确度。采用DeLong检验比较2种评分方法对csPCa的诊断效能。采用McNemar检验比较2种评分方法的敏感度和特异度。采用Kappa检验分析2名医师评估bpMRI和mpMRI评分的一致性。结果相比非csPCa组,csPCa组的PV更小、PSAD更高(均P<0.05)。csPCa组中bpMRI与mpMRI评分为4-5分病人的占比更高(76.8%和85.3%),非csPCa组中1-3分病人的占比更高(78.5%和74.2%)。bpMRI与mpMRI评分诊断csPCa的AUC值差异无统计学意义(P>0.05)。bpMRI的敏感度低于mpMRI(76.8%和85.3%,P<0.05),而特异度高于mpMRI(78.5%和74.2%,P<0.05)。bpMRI和mpMRI评分的阅片者间一致性均较好(κ=0.68和κ=0.67)。结论基于PI-RADS v2.1,bpMRI评分与mpMRI评分对PSA灰区csPCa的诊断效能相近。 展开更多
关键词 前列腺影像报告与数据系统 磁共振成像 临床显著性前列腺癌
下载PDF
增强MRI采用LI-RADS v2018对肝细胞癌的诊断效能
14
作者 贾素兰 杜静波 苏晓华 《CT理论与应用研究(中英文)》 2024年第1期35-41,共7页
目的:探讨增强MRI采用2018版肝脏影像报告和数据系统(LI-RADS)在高危人群中对肝细胞癌(HCC)的诊断效能。方法:回顾性分析本院2017年至2022年经病理证实的69例HCC患者,并且行MRI增强检查。基于LI-RADS v2018,对每个病灶MRI图像的主要/辅... 目的:探讨增强MRI采用2018版肝脏影像报告和数据系统(LI-RADS)在高危人群中对肝细胞癌(HCC)的诊断效能。方法:回顾性分析本院2017年至2022年经病理证实的69例HCC患者,并且行MRI增强检查。基于LI-RADS v2018,对每个病灶MRI图像的主要/辅助征象进行评价及LI-RADS分类。以病理结果为金标准,评价增强MRI采用LI-RADS v2018对HCC的诊断效能。采用组内相关系数(ICC)评价阅片者的一致性。结果:3位阅片者间LI-RADS分类的ICC值为0.782(95%可信区间0.713~0.841)。基于LI-RADS v2018,以LR-5为诊断标准,MRI阅片者1诊断HCC的敏感度、特异度和准确率分别为83.9%、70.4%和79.8%;阅片者2分别为80.6%、74.1%和78.7%;阅片者3分别为80.6%、77.8%和79.8%。以LR-4联合LR-5为诊断标准,阅片者1诊断HCC的敏感度、特异度和准确率分别为93.5%、63.0%和84.3%,阅片者2分别为90.3%、66.7%和83.1%,阅片者3分别为91.9%、66.7%和84.3%。结论:基于LI-RADS v2018,增强MRI在高危人群中诊断HCC具有较高的诊断价值。 展开更多
关键词 磁共振成像 肝细胞癌 2018版肝脏成像报告和数据系统
下载PDF
基于MRI影像组学鉴别胶质瘤及单发脑转移瘤的应用研究
15
作者 王静 宗会迁 +3 位作者 张娅 宋静 徐子超 彭兴珍 《中国医疗设备》 2024年第9期94-100,共7页
目的分析基于多模态磁共振成像(Magnetic Resonance Imaging,MRI)影像组学鉴别胶质瘤及单发脑转移瘤的研究进展,得出提升鉴别准确性的要素。方法通过检索PubMed、Web of Science及FMRS外文医学信息资源检索平台3个数据库,根据纳入排除标... 目的分析基于多模态磁共振成像(Magnetic Resonance Imaging,MRI)影像组学鉴别胶质瘤及单发脑转移瘤的研究进展,得出提升鉴别准确性的要素。方法通过检索PubMed、Web of Science及FMRS外文医学信息资源检索平台3个数据库,根据纳入排除标准,对纳入的文章提取数据来源、患者数量、MRI设备、MRI序列、肿瘤分割软件、分割方式、分割范围、分割类型、特征提取方法、筛选方法、机器学习分类器、最优的机器学习分类器等数据进行综合分析。结果最终纳入12篇文献进行分析,大多数研究选择MRI传统结构序列,特征筛选方法选择最多的是最小绝对收缩和选择算子,使用最多且表现最佳的机器学习分类器为随机森林。结论MRI影像组学方法在鉴别胶质瘤及单发脑转移瘤方面展现出了较高的准确性,为临床决策提高了较大帮助。 展开更多
关键词 影像组学 磁共振成像 机器学习 胶质瘤 单发脑转移瘤
下载PDF
基于临床数据和HR-MRI相关参数构建脑梗死发生的预测模型
16
作者 吴丽鹏 郑艳龙 +2 位作者 张杨 张曦 赵启利 《中国实用神经疾病杂志》 2024年第9期1077-1082,共6页
目的基于临床数据和血管壁成像技术构建颅内动脉粥样硬化(ICAS)斑块形成所致脑梗死(ACI)的预测模型。方法选取2018-02—2022-06廊坊市人民医院的ICAS斑块形成患者204例,根据是否发生ACI分为观察组(80例)与对照组(124例),所有患者均行高... 目的基于临床数据和血管壁成像技术构建颅内动脉粥样硬化(ICAS)斑块形成所致脑梗死(ACI)的预测模型。方法选取2018-02—2022-06廊坊市人民医院的ICAS斑块形成患者204例,根据是否发生ACI分为观察组(80例)与对照组(124例),所有患者均行高分辨率磁共振血管壁成像(HR-MRI)检查,收集并比较2组患者的临床数据、HR-MRI影像表现及参数,采用LASSO-Logistic回归分析ACI发生的危险因素,绘制Nomogram预测模型。结果观察组合并高血压、糖尿病比例及D-D、UA、Hcy水平高于对照组(P<0.05)。观察组斑块内出血、斑块负荷、斑块体积、重塑指数、偏心指数、最狭窄层面斑块强化率、斑块整体强化率高于对照组(P<0.05)。LASSO初筛出9个因素:高血压、糖尿病、D-D、Hcy、斑块负荷、重塑指数、偏心指数、最狭窄层面斑块强化率、斑块整体强化率,Logistic回归分析显示以上9个因素均是ICAS斑块形成所致ACI的独立危险因素(P<0.05),据此构建ICAS斑块形成所致ACI的Nomogram预测模型,该模型C-index为0.944,ROC曲线显示该模型预测ICAS斑块形成所致ACI的AUC为0.913(0.857~0.972),校准图分析显示该模型校准度为0.888。结论基于临床数据和HR-MRI相关参数构建ICAS斑块形成所致ACI的预测模型具有可行性,且预测效能较为可靠,能为临床开展防治工作提供指导。 展开更多
关键词 脑梗死 颅内动脉粥样硬化 斑块形成 临床数据 高分辨率磁共振血管壁成像 预测模型
下载PDF
基于LI-RADS v2018及MRI特征对肝细胞癌CK19表达的风险预测及预后评估 被引量:2
17
作者 鲁梦恬 瞿琦 +5 位作者 徐磊 张继云 刘茂童 姜吉锋 张涛 张学琴 《磁共振成像》 CAS CSCD 北大核心 2024年第3期107-113,121,共8页
目的 探讨2018版肝脏影像报告和数据系统(Liver Imaging Reporting and Data System version 2018,LI-RADS v2018)对肝细胞癌(hepatocellular carcinoma,HCC)细胞角蛋白19(cytokeratin 19,CK19)表达的术前预测及预后评估的价值。材料与... 目的 探讨2018版肝脏影像报告和数据系统(Liver Imaging Reporting and Data System version 2018,LI-RADS v2018)对肝细胞癌(hepatocellular carcinoma,HCC)细胞角蛋白19(cytokeratin 19,CK19)表达的术前预测及预后评估的价值。材料与方法 回顾性分析220例术前接受MRI检查并经病理证实为HCC患者的临床、病理及影像资料,包括CK19阳性组59例,CK19阴性组161例。将患者按7∶3比例分为训练集和验证集。通过单因素与多因素logistic回归分析确定CK19阳性表达HCC的独立预测因素并构建列线图评分模型。采用受试者工作特征(receiver operating characteristic,ROC)曲线分析模型诊断效能,绘制校准曲线、决策曲线评价模型的校准性能和临床适用性。计算患者的列线图得分并进行高低风险分组,采用Kaplan-Meier生存曲线分析比较不同亚组患者的总体、早期及晚期无复发生存率。结果 晕状强化(OR=3.432,P=0.045)、环形动脉期高强化(OR=32.073,P=0.017)、靶样扩散受限(OR=12.941,P=0.006)、不光滑肿瘤边缘(OR=4.590,P=0.014)及肝胆期肿瘤-肝实质相对增强比(the relative enhancement ratio,RER)(OR=0.014,P=0.023)是CK19阳性表达HCC的独立预测因素。预测模型在训练集和验证集的曲线下面积(area under the curve,AUC)分别为0.884(95%CI:0.823~0.930)、0.748(95%CI:0.625~0.846),校准曲线、决策曲线显示模型的校准性能和临床适用性较好。CK19阳性与阴性组的总体无复发生存率、高与低风险组的总体、早期及晚期无复发生存率之间均存在显著差异(P<0.05)。结论 晕状强化、环形动脉期高强化、靶样扩散受限结合不光滑肿瘤边缘、肝胆期增强定量参数可对HCC的CK19表达进行术前风险预测,并有助于评估HCC术后复发。 展开更多
关键词 原发性肝细胞癌 细胞角蛋白19 预测模型 肝脏影像报告和数据系统 磁共振成像
下载PDF
子宫肉瘤的CT及MRI影像学表现 被引量:1
18
作者 张晓燕 徐晨 +3 位作者 曲倩倩 周萍 徐瑜 邓凯 《中国CT和MRI杂志》 2024年第6期130-132,共3页
目的 分析并总结子宫肉瘤的CT及MRI影像表现。方法 回顾性分析15例经病理及手术证实为子宫肉瘤患者的临床特征、CT及MRI表现,总结并探讨其特征性影像学表现。结果 15例子宫肉瘤患者中包括子宫平滑肌肉瘤患者8例,其中4例病灶局限于宫腔... 目的 分析并总结子宫肉瘤的CT及MRI影像表现。方法 回顾性分析15例经病理及手术证实为子宫肉瘤患者的临床特征、CT及MRI表现,总结并探讨其特征性影像学表现。结果 15例子宫肉瘤患者中包括子宫平滑肌肉瘤患者8例,其中4例病灶局限于宫腔内,4例表现为盆腔巨大包块,8例病灶均呈囊实性包块;未分化子宫肉瘤1例,呈类圆形短T_(1)、长T_(2)信号,边界清,DWI呈边缘环形高信号;子宫腺肉瘤2例,表现结节状、团块状混杂密度病灶,增强扫描呈明显不均匀强化;低级别子宫内膜间质肉瘤3例,均呈T_(1)WI等或低信号、T_(2)WI高或稍高信号且DWI呈明显高信号;高级别子宫内膜间质肉瘤1例,表现为盆腔内巨大囊实性占位,病理证实病灶侵穿浆膜累及局部肠壁浆膜下组织。结论 子宫肉瘤常表现为盆腔内囊实性包块,体积较大,形态不规则,可侵犯邻近结构或发生远处转移。MRI表现较具有特征性,常表现为等或稍长T_(1)WI、混杂长T_(2)WI信号,DWI呈高或略高信号,增强扫描肿块呈明显不均匀强化。 展开更多
关键词 子宫肉瘤 影像学 电子计算机断层扫描(CT) 磁共振成像 病理学
下载PDF
面向急性缺血性脑卒中的CT生成MRI算法 被引量:1
19
作者 张美美 秦品乐 +4 位作者 柴锐 曾建潮 翟双姣 闫俊义 冯二燕 《计算机工程》 CAS CSCD 北大核心 2024年第2期317-326,共10页
急性缺血性脑卒中病灶在计算机断层扫描(CT)上表现不明显,但在核磁共振成像(MRI)上可以清晰显示。然而,当患者体内有金属植入物等特殊情况则无法进行MRI检测,使得患者的治疗受到延误。通过CT生成MRI可在急性缺血性脑卒中的诊断和治疗中... 急性缺血性脑卒中病灶在计算机断层扫描(CT)上表现不明显,但在核磁共振成像(MRI)上可以清晰显示。然而,当患者体内有金属植入物等特殊情况则无法进行MRI检测,使得患者的治疗受到延误。通过CT生成MRI可在急性缺血性脑卒中的诊断和治疗中起到至关重要的作用,但现有的医学影像跨模态生成方法从CT得到的MRI缺乏病灶信息且边界模糊。为了解决上述问题,提出一种基于影像组学和扩散生成对抗网络的急性缺血性脑卒中CT生成MRI算法,通过影像组学在CT上进行病灶特征增强,突出生成MRI的病灶信息,引入梯度损失为生成图像与真实图像增加边缘感知约束,提升生成MRI的质量。在ISLES2018挑战赛数据集上的实验结果表明,该算法生成的MRI在整体上的峰值信噪比为23.051 dB,结构相似度为0.798,皮尔逊相关系数为0.969,并且病灶区域的互信息为2.075,与现有的生成模型相比,该算法的各项指标均达到最优。此外,经3名经验丰富的放射科医生在生成的MRI上确定病灶并进行阳性/阴性分类,其中生成的MRI中无错误病灶,且分类准确率可达到86.61%,可作为一种辅助工具协助医生进行诊断。 展开更多
关键词 医学图像生成 影像组学 扩散生成对抗网络 计算机断层扫描 核磁共振成像
下载PDF
Hepatocellular carcinoma: Can LI-RADS v2017 with gadoxetic-acid enhancement magnetic resonance and diffusion-weighted imaging improve diagnostic accuracy? 被引量:8
20
作者 Tong Zhang Zi-Xing Huang +8 位作者 Yi Wei Han-Yu Jiang Jie Chen Xi-Jiao Liu Li-Kun Cao Ting Duan Xiao-Peng He Chun-Chao Xia Bin Song 《World Journal of Gastroenterology》 SCIE CAS 2019年第5期622-631,共10页
BACKGROUND The Liver Imaging Reporting and Data System(LI-RADS), supported by the American College of Radiology(ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collectio... BACKGROUND The Liver Imaging Reporting and Data System(LI-RADS), supported by the American College of Radiology(ACR), has been developed for standardizing the acquisition, interpretation, reporting, and data collection of liver imaging examinations in patients at risk for hepatocellular carcinoma(HCC). Diffusionweighted imaging(DWI), which is described as an ancillary imaging feature of LI-RADS, can improve the diagnostic efficiency of LI-RADS v2017 with gadoxetic acid-enhanced magnetic resonance imaging(MRI) for HCC.AIM To determine whether the use of DWI can improve the diagnostic efficiency of LIRADS v2017 with gadoxetic acid-enhanced magnetic resonance MRI for HCC.METHODS In this institutional review board-approved study, 245 observations of high risk of HCC were retrospectively acquired from 203 patients who underwent gadoxetic acid-enhanced MRI from October 2013 to April 2018. Two readers independently measured the maximum diameter and recorded the presence of each lesion and assigned scores according to LI-RADS v2017. The test was used to determine the agreement between the two readers with or without DWI. In addition, the sensitivity(SE), specificity(SP), accuracy(AC), positive predictive value(PPV), and negative predictive value(NPV) of LI-RADS were calculated.Youden index values were used to compare the diagnostic performance of LIRADS with or without DWI.RESULTS Almost perfect interobserver agreement was obtained for the categorization of observations with LI-RADS(kappa value: 0.813 without DWI and 0.882 with DWI). For LR-5, the diagnostic SE, SP, and AC values were 61.2%, 92.5%, and71.4%, respectively, with or without DWI; for LR-4/5, they were 73.9%, 80%, and75.9% without DWI and 87.9%, 80%, and 85.3% with DWI; for LR-4/5/M, they were 75.8%, 58.8%, and 70.2% without DWI and 87.9%, 58.8%, and 78.4% with DWI; for LR-4/5/TIV, they were 75.8%, 75%, and 75.5% without DWI and 89.7%,75%, and 84.9% with DWI. The Youden index values of the LI-RADS classification without or with DWI were as follows: LR-4/5: 0.539 vs 0.679; LR-4/5/M: 0.346 vs 0.467; and LR-4/5/TIV: 0.508 vs 0.647.CONCLUSION LI-RADS v2017 has been successfully applied with gadoxetate-enhanced MRI for patients at high risk for HCC. The addition of DWI significantly increases the diagnostic efficiency for HCC. 展开更多
关键词 HEPATOCELLULAR CARCINOMA Liver imaging REPORTING and data System magnetic resonance imaging DIFFUSION-WEIGHTED imaging Diagnosis
下载PDF
上一页 1 2 123 下一页 到第
使用帮助 返回顶部