期刊文献+
共找到74篇文章
< 1 2 4 >
每页显示 20 50 100
Automatic detection of breast lesions in automated 3D breast ultrasound with cross-organ transfer learning
1
作者 Lingyun BAO Zhengrui HUANG +7 位作者 Zehui LIN Yue SUN Hui CHEN You LI Zhang LI Xiaochen YUAN Lin XU Tao TAN 《虚拟现实与智能硬件(中英文)》 EI 2024年第3期239-251,共13页
Background Deep convolutional neural networks have garnered considerable attention in numerous machine learning applications,particularly in visual recognition tasks such as image and video analyses.There is a growing... Background Deep convolutional neural networks have garnered considerable attention in numerous machine learning applications,particularly in visual recognition tasks such as image and video analyses.There is a growing interest in applying this technology to diverse applications in medical image analysis.Automated three dimensional Breast Ultrasound is a vital tool for detecting breast cancer,and computer-assisted diagnosis software,developed based on deep learning,can effectively assist radiologists in diagnosis.However,the network model is prone to overfitting during training,owing to challenges such as insufficient training data.This study attempts to solve the problem caused by small datasets and improve model detection performance.Methods We propose a breast cancer detection framework based on deep learning(a transfer learning method based on cross-organ cancer detection)and a contrastive learning method based on breast imaging reporting and data systems(BI-RADS).Results When using cross organ transfer learning and BIRADS based contrastive learning,the average sensitivity of the model increased by a maximum of 16.05%.Conclusion Our experiments have demonstrated that the parameters and experiences of cross-organ cancer detection can be mutually referenced,and contrastive learning method based on BI-RADS can improve the detection performance of the model. 展开更多
关键词 Breast ultrasound Automated 3d breast ultrasound Breast cancers deep learning Transfer learning Convolutional neural networks Computer-aided diagnosis Cross organ learning
下载PDF
A survey of real-time rendering on Web3D application 被引量:1
2
作者 Geng YU Chang LIU +7 位作者 Ting FANG Jinyuan JIA Enming LIN Yiqiang HE Siyuan FU Long WANG Lei WEI Qingyu HUANG 《Virtual Reality & Intelligent Hardware》 EI 2023年第5期379-394,共16页
Background In recent years, with the rapid development of mobile Internet and Web3D technologies, a large number of web-based online 3D visualization applications have emerged. Web3D applications, including Web3D onli... Background In recent years, with the rapid development of mobile Internet and Web3D technologies, a large number of web-based online 3D visualization applications have emerged. Web3D applications, including Web3D online tourism, Web3D online architecture, Web3D online education environment, Web3D online medical care, and Web3D online shopping are examples of these applications that leverage 3D rendering on the web. These applications have pushed the boundaries of traditional web applications that use text, sound, image, video, and 2D animation as their main communication media, and resorted to 3D virtual scenes as the main interaction object, enabling a user experience that delivers a strong sense of immersion. This paper approached the emerging Web3D applications that generate stronger impacts on people's lives through “real-time rendering technology”, which is the core technology of Web3D. This paper discusses all the major 3D graphics APIs of Web3D and the well-known Web3D engines at home and abroad and classify the real-time rendering frameworks of Web3D applications into different categories. Results Finally, this study analyzed the specific demand posed by different fields to Web3D applications by referring to the representative Web3D applications in each particular field. Conclusions Our survey results show that Web3D applications based on real-time rendering have in-depth sectors of society and even family, which is a trend that has influence on every line of industry. 展开更多
关键词 WEB3d real-time rendering Virtual reality Cloud rendering Mobile Internet
下载PDF
用Real-time 3D技术制作VR小品
3
作者 southwest 《中国图象图形学报(B辑)》 北大核心 2003年第10期50-53,共4页
三维技术以前给人们的印象就是三维动画和CG作品,特别是三维动画,最深入人心,不过三维动画不具有交互性,不能指望依靠它实现什么互动功能。实时三维技术虽然在很早以前就有了,但主要用于游戏开发、军事科研、大型仿真等领域。
关键词 real-time 技术制作 小品 VR 3d 三维动画 三维技术 互动功能
下载PDF
Application of real-time 3d echocardiography in mitral valve repair for replacement of chordae tendineae
4
作者 黄焕雷 《外科研究与新技术》 2011年第3期186-187,共2页
Objective To investigate the surgical technique and outcomes of replacement of chordae tendineae in mitral valve repair,and evaluate the value of real-time three-di-mensional transesophageal echocardiography in the pe... Objective To investigate the surgical technique and outcomes of replacement of chordae tendineae in mitral valve repair,and evaluate the value of real-time three-di-mensional transesophageal echocardiography in the perioperative period. Methods Thirty-one patients with mitral valve prolapse underwent mitral valve repair using chordae tendineae replacement concomitant with implantation 展开更多
关键词 TIME REAL Application of real-time 3d echocardiography in mitral valve repair for replacement of chordae tendineae
下载PDF
Contrast-enhanced 3D ultrasound in the radiofrequency ablation of liver tumors 被引量:19
5
作者 Edward Leen Senthil Kumar +4 位作者 Shahid A Khan Gavin Low Keh Oon Ong Paul Tait Mike Averkiou 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第3期289-299,共11页
Liver metastases and hepatocellular carcinomas are two of the most common causes of cancer deaths in the world.Radiofrequency ablation(RFA) is a well recognized,effective and minimally invasive means of treating malig... Liver metastases and hepatocellular carcinomas are two of the most common causes of cancer deaths in the world.Radiofrequency ablation(RFA) is a well recognized,effective and minimally invasive means of treating malignant hepatic tumors.This article describes the use of contrast-enhanced 3D ultrasound(CE-3DUS) in the staging,targeting and follow-up of patients with liver tumors undergoing RFA.In particular,its value in the management of large hepatic lesions will be illustrated.Current limitations of CE-3DUS and future developments in the technique will also be discussed.In summary,CE-3DUS is useful in the RFA of liver tumors with improved detection and display of occult lesions and recurrence,in the assessment of lesional geometry and orientation for a more accurate planning and guidance of multiple RFA needle electrodes in large tumors and in the evaluation of residual or recurrent disease within the immediate and/or subsequent follow-up periods. 展开更多
关键词 Liver tumors Radiofrequency ablation Contrast enhanced 3d ultrasound
下载PDF
Stability and remote real-time monitoring of the slope slide body in the Luoshan mining area 被引量:6
6
作者 Yang Xiaojie Hou Dinggui +2 位作者 Tao Zhigang Peng Yanyan Shi Haiyang 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第5期761-765,共5页
Landslides have occurred frequently in the Luoshan mining area because of disordered mining.This paper discusses the landforms and physiognomy,hydro-meteorology,formation lithology,and geologic structure of the Luosha... Landslides have occurred frequently in the Luoshan mining area because of disordered mining.This paper discusses the landforms and physiognomy,hydro-meteorology,formation lithology,and geologic structure of the Luoshan mining area.It also describes the factors influencing the slope stability of landslide No.Ⅲ,determines the general parameters and typical section plane,analyzes the stress-strain state of the No.Ⅲ slope,and calculates its safety factors with FLAC3 D under saturated and natural conditions.Based on a stability analysis,a remote real-time monitoring system was applied to the No.Ⅲ slope,and these monitoring data were collected and analyzed. 展开更多
关键词 LANdSLIdE FLAC3d Stability analysis Remote real-time monitor
下载PDF
Transvaginal 3D Ultrasound Evaluation of Post-Cesarean Section Uterine Diverticulum 被引量:2
7
作者 Cui-Lan Li Xue-Tang Mo +6 位作者 Kai-Xuan Deng Dun-Jin Chen Xing-Cheng Gao Jin-Guo Zhai Yi-Ming Liao Hui-Ru Dai Xiang Cai 《Open Journal of Obstetrics and Gynecology》 2015年第12期698-702,共5页
Objectives: This study focused on evaluating the value of transvaginal 3D ultrasound for the diagnosis and prognostic assessment of post-cesarean section uterine diverticulum. Materials and Methods: We retrospectively... Objectives: This study focused on evaluating the value of transvaginal 3D ultrasound for the diagnosis and prognostic assessment of post-cesarean section uterine diverticulum. Materials and Methods: We retrospectively analyzed the data from 32 patients with post-cesarean section uterine diverticulum over three recent years. In all patients, transvaginal 3D ultrasound was used to measure the size of the uterine diverticulum and the thickness of the lower uterine segment (LUS) and myometrium. Patients with a LUS with a myometrial thickness under 4 mm underwent resection and repair surgery;those with a LUS with a myometrial thickness over 4 mm underwent hysteroscopic resection. The postoperative sonograms were compared with preoperative images to evaluate the efficacy of various treatments. Results: The mean length, width and depth of the uterine diverticula were 18.30 ± 2.80 mm, 9.14 ± 3.20 mm and 11.49 ± 2.71 mm, respectively. The average LUS myometrial thickness was 3.40 ± 0.80 mm (with a range of 1.6 mm - 6.3 mm). After surgery, two patients’ sonograms still showed diverticula at the post-cesarean section scar, measuring 6 mm × 7 mm × 6 mm and 6 mm × 8 mm × 4 mm. There were significant differences in the size of uterine diverticula between preoperative and postoperative sonograms (P < 0.05) and the effective rate of surgery was 93.75% (30/32). Conclusions: Transvaginal 3D ultrasound is an accurate method for detecting post-cesarean section uterine diverticulum and is helpful for assessing surgical options and prognosis. The LUS myometrial thickness, which is considered as an optional index of post-cesarean section uterine diverticulum, should be measured routinely. 展开更多
关键词 Post-Cesarean Section UTERINE dIVERTICULUM TRANSVAGINAL 3d ultrasound LUS Myometrial Thickness
下载PDF
The Clinical Value of Ultrasound Image Texture Analysis in the Diagnosis of Uterine Adhesions
8
作者 Meng Li Chanyu Zhang 《Open Journal of Obstetrics and Gynecology》 2024年第2期312-320,共9页
Purpose: This review examines the diagnostic value of transvaginal 3D ultrasound image texture analysis for the diagnosis of uterine adhesions. Materials and Methods: The total clinical data of 53 patients with uterin... Purpose: This review examines the diagnostic value of transvaginal 3D ultrasound image texture analysis for the diagnosis of uterine adhesions. Materials and Methods: The total clinical data of 53 patients with uterine adhesions diagnosed by hysteroscopy and the imaging data of transvaginal three-dimensional ultrasound from the Second Affiliated Hospital of Chongqing Medical University from June 2022 to August 2023 were retrospectively analysed. Based on hysteroscopic surgical records, patients were divided into two independent groups: normal endometrium and uterine adhesion sites. The samples were divided into a training set and a test set, and the transvaginal 3D ultrasound was used to outline the region of interest (ROI) and extract texture features for normal endometrium and uterine adhesions based on hysteroscopic surgical recordings, the training set data were feature screened and modelled using lasso regression and cross-validation, and the diagnostic efficacy of the model was assessed by applying the subjects’ operating characteristic (ROC) curves. Results: For each group, 290 texture feature parameters were extracted and three higher values were screened out, and the area under the curve of the constructed ultrasonographic scoring model was 0.658 and 0.720 in the training and test sets, respectively. Conclusion Relative clinical value of transvaginal three-dimensional ultrasound image texture analysis for the diagnosis of uterine adhesions. 展开更多
关键词 Transvaginal 3d ultrasound Intrauterine Adhesion Texture Analysis
下载PDF
Real-time Simulation of Gas Based on Smoothed Particle Hydrodynamics 被引量:1
9
作者 ZHU Xiao-lin FAN Cheng-kai LIU Yang-yang 《Computer Aided Drafting,Design and Manufacturing》 2015年第1期68-73,共6页
This paper extends the SPH method to gas simulation. The SPH (Smoothed Particles Hydrodynamics) method is the most popular method of flow simulation, which is widely used in large-scale liquid simulation. However, i... This paper extends the SPH method to gas simulation. The SPH (Smoothed Particles Hydrodynamics) method is the most popular method of flow simulation, which is widely used in large-scale liquid simulation. However, it is not found to apply to gas simulation, since those methods based on SPH can't be used in real-time simulation due to their enormous particles and huge computation. This paper proposes a method for gas simulation based on SPH with a small number of particles. Firstly, the method computes the position and density of each particle in each point-in-time, and outlines the shape of the simulated gas based on those particles. Secondly the method uses the grid technique to refine the shape with the diffusion of particle's density under the control of grid, and get more lifelike simulation result. Each grid will be assigned density according to the particles in it. The density determines the final appearance of the grid. For ensuring the natural transition of the color between adjacent grids, we give a diffuse process of density between these grids and assign appropriate values to vertexes of these grids. The experimental results show that the proposed method can give better gas simulation and meet the request of real-time. 展开更多
关键词 gas simulation smoothed particles hydrodynamics (SPH) 3d grid real-time
下载PDF
Real-Time Grouting Monitoring and Visualization Analysis System for Dam Foundation Curtain Grouting
10
作者 樊贵超 钟登华 +3 位作者 任炳昱 崔博 李晓超 岳攀 《Transactions of Tianjin University》 EI CAS 2016年第6期493-501,共9页
A real-time monitoring and 3D visualization analysis system is proposed for dam foundation curtain grouting. Based on the real-time control technology, the optimization method and the set theory, a mathematical model ... A real-time monitoring and 3D visualization analysis system is proposed for dam foundation curtain grouting. Based on the real-time control technology, the optimization method and the set theory, a mathematical model of the system is established. The real-time collection and transmission technology of the grouting data provides a data foundation for the system. The real-time grouting monitoring and dynamic alarming method helps the system control the grouting quality during the grouting process, thus, the abnormalities of grouting, such as jacking and hydraulic uplift, can be effectively controlled. In addition, the 3D grouting visualization analysis technology is proposed to establish the grouting information model(GIM). The GIM provides a platform to visualize and analyze the grouting process and results. The system has been applied to a hydraulic project of China as a case study, and the application results indicate that the real-time grouting monitoring and 3D visualization analysis for the grouting process can help engineers control the grouting quality more efficiently. 展开更多
关键词 dam foundation curtain grouting real-time monitoring dynamic alarming model grouting informationmodel (GIM) 3d visualization analysis
下载PDF
Performance Evaluation of Three-Dimensional UWB Real-Time Locating Auto-Positioning System for Fire Rescue
11
作者 Hang Yang Xunbo Li Witold Pedrycz 《Intelligent Automation & Soft Computing》 SCIE 2023年第9期3039-3058,共20页
Fire rescue challenges and solutions have evolved from straightfor-ward plane rescue to encompass 3D space due to the rise of high-rise city buildings.Hence,this study facilitates a system with quick and simplified on... Fire rescue challenges and solutions have evolved from straightfor-ward plane rescue to encompass 3D space due to the rise of high-rise city buildings.Hence,this study facilitates a system with quick and simplified on-site launching and generates real-time location data,enabling fire rescuers to arrive at the intended spot faster and correctly for effective and precise rescue.Auto-positioning with step-by-step instructions is proposed when launching the locating system,while no extra measuring instrument like Total Station(TS)is needed.Real-time location tracking is provided via a 3D space real-time locating system(RTLS)constructed using Ultra-wide Bandwidth technology(UWB),which requires electromagnetic waves to pass through concrete walls.A hybrid weighted least squares with a time difference of arrival(WLS/TDOA)positioning method is proposed to address real path-tracking issues in 3D space and to meet RTLS requirements for quick computing in real-world applications.The 3D WLS/TDOA algorithm is theoretically constructed with the Cramer-Rao lower bound(CRLB).The computing complexity is reduced to the lower bound for embedded hardware to directly compute the time differential of the arriving signals using the time-to-digital converter(TDC).The results of the experiments show that the errors are controlled when the positioning algorithm is applied in various complicated situations to fulfill the requirements of engineering applications.The statistical analysis of the data reveals that the proposed UWB RTLS auto-positioning system can track target tags with an accuracy of 0.20 m. 展开更多
关键词 3d space positioning ULTRA-WIdEBANd real-time locating system time difference of arrival Cramer-Rao lower bound fire rescue
下载PDF
实时超声造影与3D超声融合成像导航评估微波消融治疗原发性肝癌患者价值研究 被引量:4
12
作者 蓝思荣 徐继威 +3 位作者 张耀明 李雄 沈登文 苏鸿辉 《实用肝脏病杂志》 CAS 2022年第6期889-892,共4页
目的探讨采用实时超声造影与3D超声融合成像导航评估微波消融(MWA)治疗原发性肝癌(PLC)患者的疗效。方法2017年2月~2021年2月梅州市人民医院收治的102例PLC患者,被随机分为观察组51例和对照组51例,两组均行MVA术治疗,其中对照组术中采... 目的探讨采用实时超声造影与3D超声融合成像导航评估微波消融(MWA)治疗原发性肝癌(PLC)患者的疗效。方法2017年2月~2021年2月梅州市人民医院收治的102例PLC患者,被随机分为观察组51例和对照组51例,两组均行MVA术治疗,其中对照组术中采用常规超声造影评估消融范围,在观察组采用实时超声造影联合3D超声融合成像导航评估。随访1年,记录两组总体生存率。结果观察组完全消融率和补充消融率分别为94.1%和19.6%,显著高于对照组的78.4%和3.9%(P<0.05);术后,观察组发生出血、切口感染、周围脏器损伤、胆漏和胸腹腔积液发生率为17.7%,与对照组的21.6%比,差异无统计学意义(P>0.05);随访1年,观察组肝内肿瘤复发率为10.0%,显著低于对照组的28.0%(x^(2)=5.26,P=0.02);观察组1 a总体生存率为96.0%,而对照组为84.0%(Log-Rank x^(2)=22.159,P<0.001)。结论采用实时超声造影联合3D超声融合成像导航可用于评估MWA治疗PLC患者术中消融范围,对及时补充消融有帮助,并最终提高疗效。 展开更多
关键词 原发性肝癌 微波消融 实时超声造影 3d超声融合成像导航 治疗
下载PDF
State-of-the-art imaging techniques in endoscopic ultrasound 被引量:5
13
作者 Adrian Sftoiu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第6期691-696,共6页
Endoscopic ultrasound (EUS) has recently evolved through technological improvement of equipment,with a major clinical impact in digestive and mediastinal diseases.State-of-the-art EUS equipment now includes real-time ... Endoscopic ultrasound (EUS) has recently evolved through technological improvement of equipment,with a major clinical impact in digestive and mediastinal diseases.State-of-the-art EUS equipment now includes real-time sono-elastography,which might be useful for a better characterization of lesions and increased accuracy of differential diagnosis (for e.g.lymph nodes or focal pancreatic lesions).Contrast-enhanced EUS imaging is also available,and is already being used for the differential diagnosis of focal pancreatic masses.The recent development of low mechanical index contrast harmonic EUS imaging offers hope for improved diagnosis,staging and monitoring of anti-angiogenic treatment.Tridimensional EUS (3D-EUS) techniques can be applied to enhance the spatial understanding of EUS anatomy,especially for improved staging of tumors,obtained through a better assessment of the relationship with major surrounding vessels.Despite the progress gained through all these imaging techniques,they cannot replace cytological or histological diagnosis.However,real-time optical histological diagnosis can be achieved through the use of single-fiber confocal laser endomicroscopy techniques placed under real-time EUS-guidance through a 22G needle.Last,but not least,EUS-assisted natural orifice transluminal endoscopic surgery (NOTES) procedures offer a whole new area of imaging applications,used either for combination of NOTES peritoneoscopy and intraperitoneal EUS,but also for access of retroperitoneal organs through posterior EUS guidance. 展开更多
关键词 Endoscopic ultrasound real-time sono-elastography CONTRAST-ENHANCEMENT Tridimensional 3d Hybrid imaging Endoscopic ultrasound-guided fine needle aspiration
下载PDF
Detecting Accuracy of Three Dimensional Power Doppler (3DPD) Vascular Indices for Prenatal Diagnosis of Morbidly Adherent Placenta in Patients with Placenta Previa 被引量:2
14
作者 Ahmed Sherif Abdel-Hamid Maged Mahmoud Elshourbagy +1 位作者 Mohamed Sayed Aly Shahira Zakaria Mohamed Ali Ghaly 《Open Journal of Obstetrics and Gynecology》 2020年第1期49-64,共16页
Objective:?The study’s objective was to assess the accuracy of using prenatal 3-dimensional power Doppler analysis of vascular placental indices to accurately diagnose morbidly adherent placenta objectively. Backgrou... Objective:?The study’s objective was to assess the accuracy of using prenatal 3-dimensional power Doppler analysis of vascular placental indices to accurately diagnose morbidly adherent placenta objectively. Background:?Traditionally, 2D ultrasound was used for the diagnosis of a suspected morbidly adherent placenta (MAP) previa. More objective techniques like 3D power Doppler haven’t been well studied. Study Design:?A prospective cohort study?is?designed for women with gestational age between 28 and?32 weeks with suspected placenta previa. Patients were examined by 2D ultrasound which was used in management decisions.?3D Power Doppler’s VI, FI and VFI were measured during the same examination after manual tracing of placenta;data were blinded to obstetricians. Histopathology was performed to confirm MAP. Results: Our results showed that the 3D power Doppler VI ≥ 16 predicted the diagnosis of MAP with 100% sensitivity, 100% specificity which is better than those of 2D ultrasound. While VI > 33.1 measured by 3D Doppler predicted severe MAP with a sensitivity of 73.9% and specificity of 86.4%, which was superior to 2D ultrasound. Conclusion:?In patients with placenta previa, the 3D Doppler’s vascular index accurately predicts MAP. Furthermore, vascular and vascular flow indices of 3D Doppler were more predictive of severe cases of MAP compared to 2D ultrasound. 展开更多
关键词 3d COLOR dOPPLER 2d ultrasound PLACENTAL VASCULAR Indices Morbidly Adherent PLACENTA PLACENTA Previa
下载PDF
3-D Animation as Applied to the Solving of Coupling Relations in the 6-DOF Parallel Robot
15
作者 徐雷麟 王立荣 李恩光 《Journal of Donghua University(English Edition)》 EI CAS 2002年第4期98-101,共4页
How to solve the coupling relations in a 6 - DOF parallel robot quickly and accurately within the limits of realtime control is a critical problem. In traditional analytic method, the complicated mathemtical model mus... How to solve the coupling relations in a 6 - DOF parallel robot quickly and accurately within the limits of realtime control is a critical problem. In traditional analytic method, the complicated mathemtical model must first be constructed and then solved by programming.Obviously, this method is not very practical. This paper,therefore, proposes a new way of approach with a new method using 3- D animation for the solving of coupling relations in the 6 - DOF parallel robot. This method is much simpler and its solving accuracy approaches that of the more complicated analytic method. 展开更多
关键词 parallel robot the COUPLING RELATIONS of movement 3 - d animation simulation technology real-time control
下载PDF
Resection of Vaginal Septum in Obstructed Hemivagina and Ipsilateral Renal Anomaly: Utility of Three Dimensional Intraoperative Ultrasound
16
作者 Conway Xu Shannon M. Osborne +2 位作者 Jonia Alshiek S. Abbas Shobeiri Rachel K. Casey 《Open Journal of Obstetrics and Gynecology》 2021年第4期355-359,共5页
<strong>Background:</strong><span style="font-family:Verdana;"> Obstructed hemivagina and ipsilateral renal anomaly (OHVIRA)</span><span style="font-family:""><... <strong>Background:</strong><span style="font-family:Verdana;"> Obstructed hemivagina and ipsilateral renal anomaly (OHVIRA)</span><span style="font-family:""><span style="font-family:Verdana;"> syndrome is a rare congenital condition of the female urogenital tract, presenting intraoperative challenges. We demonstrate the utility of three dimensional intraoperative ultrasound to better delineate anatomy and aid in optimal resection of the vaginal septum. </span><b><span style="font-family:Verdana;">Case:</span></b><span style="font-family:Verdana;"> A 12-year-old female was referred to pediatric and adolescent gynecology for irregular periods and evaluation of her gynecologic organs. Imaging studies confirmed OHVIRA syndrome. She underwent uncomplicated vaginal septum resection, guided by three dimensional intraoperative ultrasound. </span><b><span style="font-family:Verdana;">Summary and Conclusion:</span></b><span style="font-family:Verdana;"> Intraoperative ultrasound can better delineate challenging anatomy. We show that three dimensional intraoperative ultrasound offers significant advantages over traditional two dimensional ultrasound and is a supplement to MRI, which may be helpful in complex anatomical cases like OHVIRA syndrome.</span></span> 展开更多
关键词 OHVIRA Syndrome 3d Intraoperative ultrasound
下载PDF
珠线式模板在Freehand超声图像快速标定中的应用 被引量:4
17
作者 么娆 陆文华 +1 位作者 胡盛斌 贾慈力 《机械工程学报》 EI CAS CSCD 北大核心 2016年第22期24-30,共7页
为了精确标定freehand超声图像坐标系与固定于超声探头上的跟踪设备坐标系间坐标转换关系,提出一种"Z"形珠线模板,由双层"Z"形棉线与精确定位的圆珠构成。定位珠能够引导用户将探头准确定位,即将定位珠全部收入图... 为了精确标定freehand超声图像坐标系与固定于超声探头上的跟踪设备坐标系间坐标转换关系,提出一种"Z"形珠线模板,由双层"Z"形棉线与精确定位的圆珠构成。定位珠能够引导用户将探头准确定位,即将定位珠全部收入图像视野中。计算定位珠在超声图像中成像点间距的比例关系,根据其相应的模板空间间距比例制定优化算法,校准用户拾取的图像坐标。应用同源点匹配算法得到超声图像平面坐标系与磁跟踪设备坐标系间的空间转换关系,从而实现2-D超声图像向3-D空间坐标系的定位转换。标定结果显示此方法与以往的标定方法相比:加快了标定速度,且标定精度与重建精度有所提高。试验采用磁定位方式进行探头的跟踪定位,此方法同样适用于其他定位方式。 展开更多
关键词 超声图像标定 引导模板 自由式扫描 磁定位跟踪 三维定位
下载PDF
DSA、常规超声与实时三维超声在颈动脉内膜剥脱术术前的诊断价值 被引量:7
18
作者 王立娟 勇强 《血管与腔内血管外科杂志》 2016年第1期36-40,共5页
颈动脉粥样硬化性狭窄是发生缺血性脑卒中的常见原因,目前临床外科治疗颈动脉硬化性狭窄的标准术式是颈动脉内膜剥脱术(carotid endarterectomy,CEA),而正确判断颈动脉是否狭窄、狭窄的程度、斑块的性质以及斑块的位置、形态等,对手术... 颈动脉粥样硬化性狭窄是发生缺血性脑卒中的常见原因,目前临床外科治疗颈动脉硬化性狭窄的标准术式是颈动脉内膜剥脱术(carotid endarterectomy,CEA),而正确判断颈动脉是否狭窄、狭窄的程度、斑块的性质以及斑块的位置、形态等,对手术适应证及手术时机的选择以及手术效果的评估等均有重要的临床指导价值。数字减影与血管造影(Digital subtraction angiography,DSA)被认为是目前评估颈动脉狭窄与闭塞的金标准,可指导介入的治疗过程以及预后评估;常规超声可以直接显示斑块的位置、形态和评估狭窄程度等,是颈动脉狭窄的首选检查方法;三维超声作为常规超声的重要发展,不仅能够立体显示颈动脉斑块的位置、形态和管腔情况,而且能够对颈动脉斑块进行精确的测量,对斑块性质做出评估,同时还具有无创性、无放射性、操作方便、成像快捷、重复性好等优点,有望成为CEA术前制定更加合理的手术方案的影像学检查手段。 展开更多
关键词 dSA超声 实时三维超声 CEA
下载PDF
7-氨基-6-氰基-5-(3-硝基苯基)吡喃并嘧啶-2,4-二酮的合成 被引量:3
19
作者 靳通收 刘利宾 +1 位作者 赵莹 李同双 《化学试剂》 CAS CSCD 北大核心 2005年第9期561-562,共2页
报道了常温、超声辐射、水中、无催化剂条件下,以3-硝基苯甲醛、丙二腈和巴比妥酸为原料合成标题化合物的方法。考察了超声技术、反应时间及反应温度对反应的影响。最佳反应条件为:室温、超声辐射2h,收率为86.2%。
关键词 7-氨基-6-氰基-5-(3-硝基苯基)吡哺并嘧啶-2 4-二酮 巴比妥酸 超声技术 合成
下载PDF
TPUS检查对子宫全切术后患者PFD发生情况的评估价值 被引量:4
20
作者 季润琰 何伯圣 吴静 《影像科学与光化学》 CAS 北大核心 2021年第4期601-605,共5页
本文旨在分析经会阴超声(TPUS)检查对子宫全切术后患者盆底功能障碍(PFD)发生情况的评估价值。选取行子宫全切术的患者157例,根据术后是否出现PFD,分为未发生PFD组103例和发生PFD组54例,均行TPUS检查。结果显示,与未发生PFD组相比,发生... 本文旨在分析经会阴超声(TPUS)检查对子宫全切术后患者盆底功能障碍(PFD)发生情况的评估价值。选取行子宫全切术的患者157例,根据术后是否出现PFD,分为未发生PFD组103例和发生PFD组54例,均行TPUS检查。结果显示,与未发生PFD组相比,发生PFD组膀胱下移距离、直肠下移距离、阴道穹窿下移距离、膀胱尿道后角、肛提肌裂孔左右径、前后径、面积、周长升高,尿道倾斜角降低(P<0.05)两组肛提肌厚度比较,差异无统计学意义(P>0.05)。与经会阴二维、三维、四维超声检查单独检查相比,三项联合诊断价值较高(P<0.05)。研究结果表明,子宫全切术患者术后存在PFD,TPUS检查对PFD的诊断价值较为理想,可用于子宫全切术后患者PFD发生的临床诊断评估。 展开更多
关键词 经会阴二维超声 经会阴三维超声 经会阴四维超声 子宫全切术 盆底功能障碍
下载PDF
上一页 1 2 4 下一页 到第
使用帮助 返回顶部