目的:了解三维超声成像在眼部常见疾病中的图像特点以及新的诊断方法的优越性.方法:应用OTI 3D i-Scan眼科专用超声仪先作二维B超检查,然后探头沿垂直轴旋转180度,获取连续二维扫描图像,经计算机处理重建成三维图像.结果:视网膜脱离的...目的:了解三维超声成像在眼部常见疾病中的图像特点以及新的诊断方法的优越性.方法:应用OTI 3D i-Scan眼科专用超声仪先作二维B超检查,然后探头沿垂直轴旋转180度,获取连续二维扫描图像,经计算机处理重建成三维图像.结果:视网膜脱离的三维立体图像表现为半球形、喇叭形等;玻璃体后脱离呈片状、漏斗形膜,玻璃体混浊呈雪花形;脉络膜黑色素瘤显示扁圆球形或圆形实质性团块,球内异物呈现三角形强回声团块,近球壁出现球后组织声影等.结论:应用三维超声成像可以显示眼部病变的立体形状、内部任何断面结构、表面特征、不同结构的空间关系,扩展了对图像的观察范围,精确计算病变的体积,监视病变的变化及治疗效果.展开更多
Prediction of channel dredging volume is critical for project cost estimation. However, many proposed approximate methods are not accurate. This paper presents a novel numerical method to accurately calculate the dred...Prediction of channel dredging volume is critical for project cost estimation. However, many proposed approximate methods are not accurate. This paper presents a novel numerical method to accurately calculate the dredg- ing volume using a 3D stratum model (DSM) and a channel surface model. First, the 3D DSM is constructed rapidly yet accurately from non-uniform rational B-splines (NURBS) surfaces through Boolean operation between a physical terrain model and a stratum surfaces model. Then, a parametric channel surface model is built from cross-section data and a channel center line using code implemented in the VC++ programming language. Finally, the volumes of different types of physical stratums can be calculated automatically and hierarchically to determine the dredging volume. Practical application shows that the DSM method is more precise and faster compared to the section method, and that the implementation of the developed software provides an interactive graphical user interface and visual presentation.展开更多
文摘目的:了解三维超声成像在眼部常见疾病中的图像特点以及新的诊断方法的优越性.方法:应用OTI 3D i-Scan眼科专用超声仪先作二维B超检查,然后探头沿垂直轴旋转180度,获取连续二维扫描图像,经计算机处理重建成三维图像.结果:视网膜脱离的三维立体图像表现为半球形、喇叭形等;玻璃体后脱离呈片状、漏斗形膜,玻璃体混浊呈雪花形;脉络膜黑色素瘤显示扁圆球形或圆形实质性团块,球内异物呈现三角形强回声团块,近球壁出现球后组织声影等.结论:应用三维超声成像可以显示眼部病变的立体形状、内部任何断面结构、表面特征、不同结构的空间关系,扩展了对图像的观察范围,精确计算病变的体积,监视病变的变化及治疗效果.
基金Supported by the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (No. 51021004)National Natural Science Foundation of China(No. 50879056)National Key Technologies R&D Program in the 12th Five-Year Plan of China(No. 2011BAB10B06)
文摘Prediction of channel dredging volume is critical for project cost estimation. However, many proposed approximate methods are not accurate. This paper presents a novel numerical method to accurately calculate the dredg- ing volume using a 3D stratum model (DSM) and a channel surface model. First, the 3D DSM is constructed rapidly yet accurately from non-uniform rational B-splines (NURBS) surfaces through Boolean operation between a physical terrain model and a stratum surfaces model. Then, a parametric channel surface model is built from cross-section data and a channel center line using code implemented in the VC++ programming language. Finally, the volumes of different types of physical stratums can be calculated automatically and hierarchically to determine the dredging volume. Practical application shows that the DSM method is more precise and faster compared to the section method, and that the implementation of the developed software provides an interactive graphical user interface and visual presentation.
