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公开(公告)号：US08761540B2
公开(公告)日：2014-06-24
申请号：US13160111
申请日：2011-06-14
IPC分类号： G06K9/40
CPC分类号： G06T11/008
摘要： Noise assessment is important to image quality evaluation as well as image processing. For example, the noise level estimation is used as criteria for terminating an iterative noise reduction process. To determine a meaningful noise level, the pixels in featureless regions are separated from the rest of the image. A new concept of pseudo-standard deviation (PSD) is introduced to automatically determine simple and reliable noise level estimates. Furthermore, a histogram of PSD is constructed with fine bins to calculate the moving average of the histogram. The first peak in filtered histogram gives the most representative noise measure as a desired approximation of true standard deviation.
摘要翻译： 噪声评估对图像质量评估和图像处理很重要。 例如，噪声水平估计被用作终止迭代降噪过程的标准。 为了确定有意义的噪声电平，无特征区域中的像素与图像的其余部分分离。 引入了伪标准偏差（PSD）的新概念，以自动确定简单可靠的噪声电平估计。 此外，PSD的直方图由精细仓组成，以计算直方图的移动平均值。 滤波直方图中的第一个峰值给出最具代表性的噪声测量值作为真正标准偏差的期望近似值。
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公开(公告)号：US08294717B2
公开(公告)日：2012-10-23
申请号：US12492754
申请日：2009-06-26
IPC分类号： G06T11/20
CPC分类号： G06K9/6226 , G06K9/342 , G06T11/005 , G06T2211/408
摘要： Three or more materials are advantageously separated from dual energy data by using a material separation technique. To effectively separate material clusters, a density plot is introduced to automatically render cluster separations. Initially, the projection data optionally undergo data-domain dual energy decomposition. Then, the image data is plotted in a vector plot whose axes are the low HU values and the high HU values. For a given data point in the vector plot, a number of data points is counted within in a region of interest surrounding the given data point to generate a density plot where each point now represents a density level surrounding the data point. Thus, clustering of a certain material is visualized by a predetermined color assignment scheme. Furthermore, special image processing methods such as Gaussian decomposition are used to improve the accuracy of material separation. In addition, the HSL color model may be used for better visualization and to bring a new dimension in material separation display.
摘要翻译： 通过使用材料分离技术，三种或更多种材料有利地与双能量数据分离。 为了有效地分离材料簇，引入了一个密度图来自动渲染聚类分离。 最初，投影数据可选地进行数据域双能量分解。 然后，将图像数据绘制在轴为低HU值和高HU值的矢量图中。 对于矢量图中的给定数据点，在给定数据点周围的感兴趣区域内计数多个数据点，以生成密度图，其中每个点现在表示围绕数据点的密度水平。 因此，通过预定的颜色分配方案可视化某种材料的聚类。 此外，使用诸如高斯分解的特殊图像处理方法来提高材料分离的精度。 此外，HSL颜色模型可用于更好的可视化，并在材料分离显示中带来新的维度。
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公开(公告)号：US08538114B2
公开(公告)日：2013-09-17
申请号：US13154124
申请日：2011-06-06
申请人： Zhi Yang , Alexander Zamyatin , Yu Zou , Michael D. Silver
发明人： Zhi Yang , Alexander Zamyatin , Yu Zou , Michael D. Silver
IPC分类号： G06K9/00
CPC分类号： G06T5/002 , G06T5/20 , G06T2207/10081 , G06T2207/20008
摘要： Photon starvation causes streaks and noise and seriously impairs the diagnostic value of the CT imaging. To reduce streaks and noise, a new scheme of adaptive Gaussian filtering relies on the diffusion-derived scale-space concept in one embodiment of the current invention. In scale-space view, filtering by Gaussians of different sizes is similar to decompose the data into a sequence of scales. As the scale measure, the variance of the filter linearly relates to the noise standard deviation of a predetermined noise model in the new filtering method. The new filter has only one optional parameter that remains stable once tuned. Although single-pass processing using the new filter generally achieves desired results, iterations are optionally performed.
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4.发明授权Spatial resolution improvement in computer tomography (CT) using iterative reconstruction 有权使用迭代重建的计算机断层扫描（CT）中的空间分辨率改善公开(公告)号：US08837797B2
公开(公告)日：2014-09-16
申请号：US13347398
申请日：2012-01-10
申请人： Alexander Zamyatin , Michael D. Silver , Daxin Shi
发明人： Alexander Zamyatin , Michael D. Silver , Daxin Shi
IPC分类号： G06K9/00
CPC分类号： G06T11/006 , G06T2211/416 , G06T2211/424
摘要： Spatial resolution is substantially improved by simulating a system blur kernel including an angle variable in the forward projection during a predetermined iterative reconstruction technique. The iterative reconstruction acts as a deconvolution, which overcomes certain restrictions of system optics. In general, resolution is substantially improved with cone beam and helical data without a large increase in noise.
摘要翻译： 通过在预定的迭代重建技术期间模拟包括前向投影中的角度变量的系统模糊核，空间分辨率大大提高。 迭代重建作为反卷积，克服了系统光学的某些限制。 通常，锥形束和螺旋数据的分辨率大大提高，而噪声没有大的增加。
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5.发明授权Method and system for supplementing detail image in successive multi-scale reconstruction 有权在连续多尺度重建中补充细节图像的方法和系统公开(公告)号：US08625870B2
公开(公告)日：2014-01-07
申请号：US13276677
申请日：2011-10-19
申请人： Alexander Zamyatin , Mihail Petru Dinu , Daxin Shi
发明人： Alexander Zamyatin , Mihail Petru Dinu , Daxin Shi
CPC分类号： G06T11/006 , A61B6/5258
摘要： The image reconstruction method and system reconstructs a multi-scale image using a set of predetermined nested 3D grids, and a zoomed image is reconstructed without losing details. The multiple steps uses a decreasing grid size to reconstruct an ultimately zoomed image in region of interest without degrading image quality.
摘要翻译： 图像重建方法和系统使用一组预定的嵌套3D网格重建多尺度图像，并且重建放大的图像而不丢失细节。 多个步骤使用减小的网格尺寸来重建最感兴趣的区域中的图像，而不降低图像质量。
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6.发明授权Method and system for substantially reducing artifacts in circular cone beam computer tomography (CT) 有权圆锥束计算机断层扫描（CT）中大幅减少假象的方法和系统公开(公告)号：US08731269B2
公开(公告)日：2014-05-20
申请号：US13276841
申请日：2011-10-19
CPC分类号： G06T11/006 , A61B6/583 , G06T2211/416
摘要： Cone beam artifacts arise in circular CT reconstruction. The cone beam artifacts are substantially removed by reconstructing a reference image from measured data at circular source trajectory, generating synthetic data by forward projection of the reference image along a pre-determined source trajectory, which supplements the circular source trajectory to a theoretically complete trajectory, reconstructing a correction image from the synthetic data and substantially reducing the cone beam artifacts by generating a corrected image using the reference image and the correction image.
摘要翻译： 锥形束伪影出现在圆形CT重建中。 通过从圆形源轨迹上的测量数据重建参考图像，基本上去除锥形束伪影，通过沿预定源轨迹向前投影参考图像，从而产生合成数据，该轨迹将圆形源轨迹补充到理论上完整的轨迹， 从合成数据重建校正图像，并通过使用参考图像和校正图像生成校正图像来显着减小锥形束伪影。
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公开(公告)号：US08270561B2
公开(公告)日：2012-09-18
申请号：US12903508
申请日：2010-10-13
IPC分类号： A61B6/00
CPC分类号： A61B6/032 , A61B6/027 , A61B6/4085 , A61B6/5205 , A61B6/5288 , G06T11/005 , G06T2211/412
摘要： Embodiments and processes of computer tomography perform tasks associated with weighting projection data based upon at least one motion index such as electrocardiogram gated reconstruction, view-based motion map and ray-based motion map. Other embodiments and processes of computer tomography perform tasks associated with weighting projection data based upon at least one motion index and another index that is associated with certain geometric characteristics of a cone beam.
摘要翻译： 计算机断层摄影的实施例和过程基于至少一个运动索引（例如心电图门控重建，基于视图的运动图和基于射线的运动图）来执行与加权投影数据相关联的任务。 计算机断层摄影的其他实施例和过程基于至少一个运动索引和与锥形束的某些几何特征相关联的另一索引来执行与加权投影数据相关联的任务。
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8.发明授权Method and system for substantially reducing streak artifacts in helical cone beam computer tomography (CT) 有权螺旋锥束计算机断层扫描（CT）中基本上减少条纹伪影的方法和系统公开(公告)号：US08724876B2
公开(公告)日：2014-05-13
申请号：US13275814
申请日：2011-10-18
申请人： Alexander Zamyatin , Thomas Labno
发明人： Alexander Zamyatin , Thomas Labno
CPC分类号： G06T11/006 , A61B6/583 , G06T11/005
摘要： Streak artifacts arise in helical CT reconstruction with cone beam weighting (CBW) with helical pitch ratio between 0.5 and 1.0 in a prevalent 2PI mode. The sreak artifacts are substantially removed by applying upsampling to the measured data in the segment direction before weighting. Furthermore, by making the upsampling adaptive to the view Z-position, an amount of extra processing is greatly reduced to near 1%.
摘要翻译： 在普遍的2PI模式下，锥形束加权（CBW）在螺旋桨距比为0.5和1.0之间的螺旋CT重建中出现条纹伪影。 通过在加权之前对片段方向上的测量数据应用上采样，基本上去除了蝙蝠伪影。 此外，通过使上视采样能够适应于视图Z位置，额外的处理量大大降低到接近1％。
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9.发明授权Method and system for expanding axial coverage in iterative reconstruction in computer tomography (CT) 有权计算机断层扫描（CT）迭代重建中扩大轴向覆盖的方法和系统公开(公告)号：US08712134B2
公开(公告)日：2014-04-29
申请号：US13275679
申请日：2011-10-18
申请人： Alexander Zamyatin , Daxin Shi , Mihail Petru Dinu
发明人： Alexander Zamyatin , Daxin Shi , Mihail Petru Dinu
CPC分类号： G06T11/005 , G06T2211/424 , G06T2211/432
摘要： The image generation method and system generates an image using a predetermined iterative reconstruction technique from cone beam data that has been expanded by adding additional data, and an instance of the iteration process is weighted according to a corresponding validation weight during the reconstruction. Optionally, an instance of the iteration process is weighted according to a combination of weights during the reconstruction. The predetermined combination of the weights includes axial weights based upon a validity value of the expanded data and statistical weights.
摘要翻译： 图像生成方法和系统使用已经通过添加附加数据扩展的锥形束数据使用预定的迭代重建技术来生成图像，并且在重建期间根据相应的验证权重对迭代过程的实例进行加权。 可选地，根据重建期间权重的组合对迭代过程的实例进行加权。 权重的预定组合包括基于扩展数据和统计权重的有效性的轴向权重。
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10.发明授权公开(公告)号：US10304217B2
公开(公告)日：2019-05-28
申请号：US13561674
申请日：2012-07-30
摘要： An image is reconstructed based upon a filtered backprojection (FBP) technique using a reconstruction filter which is customized or shaped by parameters including a weight value that is determined for weighing projection data according to a predetermined noise model. The weight value is determined based upon rays or views in the projection data. A regularization term is also combined with the noise-weighted FBP.
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