公开(公告)号：US6038278A

公开(公告)日：2000-03-14

申请号：US108676

申请日：1998-07-01

申请人： Jiang Hsieh ,  Kishore Acharya ,  Sandeep Dutta

发明人： Jiang Hsieh ,  Kishore Acharya ,  Sandeep Dutta

IPC分类号： A61B6/03 ,  G06T1/00 ,  G06T11/00

CPC分类号： A61B6/032 ,  A61B6/4085 ,  G06T11/005

摘要： The present invention, in one form, is a system for performing image reconstruction from projection data acquired in a helical scan. More specifically, the system implements an incremental reconstruction algorithm for helical scan projection data which does not require filtering, weighting and backprojecting such projection data for generating each image. Particularly, a segmentation algorithm divides the projection into a plurality of segments so that subsequent images are generated by generating image data only for those segments that have changed from the base image.

摘要翻译： 本发明以一种形式是用于从螺旋扫描中获取的投影数据执行图像重建的系统。 更具体地，该系统对螺旋扫描投影数据实施增量重建算法，该算法不需要滤波，加权和反投影这种用于生成每个图像的投影数据。 特别地，分割算法将投影分成多个段，使得仅通过从基本图像改变的那些段生成图像数据来生成后续图像。

公开(公告)号：US6023494A

公开(公告)日：2000-02-08

申请号：US774868

申请日：1996-12-19

申请人： Robert Senzig ,  Jiang Hsieh

发明人： Robert Senzig ,  Jiang Hsieh

IPC分类号： A61B6/03 ,  A61B6/06 ,  G01N23/04 ,  G01N23/00

CPC分类号： A61B6/032 ,  A61B6/027 ,  A61B6/06 ,  G01N23/046 ,  G01N2223/419 ,  G01N2223/612

摘要： The present invention, in one form, is a method for modifying slice thickness during a helical scan without interrupting the scan. The method includes identifying adjacent and different regions within an object to be scanned. A transition region also is identified to include a portion of each of two adjacent regions and the interface therebetween. Slice thickness is modified during the scan so that redundant data is obtained in the transition region. Particularly, in one embodiment, a variable collimator is used to scan a first region with a first slice thickness. The variable collimator is rotated at the interface between the two adjacent regions, without interrupting table translation, to scan the second region with a second slice thickness. When changing the slice thickness, the collimator also is swept so that the x-ray beam with the second slice thickness re-scans a portion of the first region within the transition region. More particularly, the collimator is swept so that the transition region is scanned with both slice thicknesses.

摘要翻译： 本发明以一种形式是在螺旋扫描期间修改切片厚度而不中断扫描的方法。 该方法包括识别待扫描对象内的相邻区域和不同区域。 过渡区域也被识别为包括两个相邻区域中的每一个的一部分及其间的界面。 在扫描期间修改切片厚度，以便在过渡区域获得冗余数据。 特别地，在一个实施例中，使用可变准直仪来扫描具有第一切片厚度的第一区域。 可变准直器在两个相邻区域之间的界面处旋转，而不中断台平移，以第二切片厚度扫描第二区域。 当改变切片厚度时，准直仪也被扫描，使得具有第二切片厚度的X射线束重新扫描过渡区域内的第一区域的一部分。 更具体地，扫描准直器，以便以两个切片厚度扫描过渡区域。

公开(公告)号：US5907593A

公开(公告)日：1999-05-25

申请号：US978802

申请日：1997-11-26

申请人： Jiang Hsieh ,  Stephen W. Metz ,  Girish Saligram ,  Guy M. Besson ,  Hui Hu ,  Sandeep Dutta ,  Robert F. Senzig ,  Min Xie

发明人： Jiang Hsieh ,  Stephen W. Metz ,  Girish Saligram ,  Guy M. Besson ,  Hui Hu ,  Sandeep Dutta ,  Robert F. Senzig ,  Min Xie

IPC分类号： A61B6/03 ,  G06T11/00

CPC分类号： G06T11/006 ,  A61B6/027 ,  G06T2211/421 ,  G06T2211/428 ,  Y10S378/901

摘要： A CT Fluoro system having an architecture and algorithms which facilitate increasing the frame rate and providing acceptable image quality is described. Generally, and in one embodiment, the system includes apparatus and algorithms that speed-up image reconstruction and reduce image artifacts that may result from such fast reconstruction. The fast reconstruction is achieved by performing, for example, view compression, channel compression, backprojection with reduced delay, and parallel processing.

摘要翻译： 描述了具有便于增加帧速率并提供可接受的图像质量的架构和算法的CT氟系统。 通常，在一个实施例中，该系统包括加速图像重构并减少可能由这种快速重建产生的图像伪像的装置和算法。 通过执行例如视图压缩，信道压缩，具有减少的延迟的反投影和并行处理来实现快速重建。

公开(公告)号：US5864598A

公开(公告)日：1999-01-26

申请号：US837545

申请日：1997-04-21

申请人： Jiang Hsieh ,  Stanley H. Fox

发明人： Jiang Hsieh ,  Stanley H. Fox

IPC分类号： A61B6/03 ,  H04N5/32

CPC分类号： H04N5/32 ,  A61B6/027 ,  Y10S378/901

摘要： The present invention, in one form, is a system for generating a high resolution image of an object from projection data acquired during a computed tomography scan. The system includes a gantry having an x-ray source which rotates around the object. The x-ray source emits an x-ray beam which is collimated with a collimator having a collimator aperture to define an x-ray beam width, or slice thickness. The projection data is reconstructed to generate image data for adjacent image slices. A deconvolution algorithm is applied to the image data to generate a deconvolved image having a finer, i.e., smaller, resolution than the collimator aperture.

摘要翻译： 在一种形式中，本发明是一种用于在计算机断层摄影扫描期间从投影数据生成物体的高分辨率图像的系统。 该系统包括具有围绕物体旋转的x射线源的台架。 X射线源发射X射线束，该X射线束用具有准直器孔径的准直仪准直，以限定X射线束宽度或切片厚度。 重建投影数据以生成相邻图像切片的图像数据。 将去卷积算法应用于图像数据以产生具有比准直器孔径更精细，即更小的分辨率的解卷积图像。

公开(公告)号：US5835559A

公开(公告)日：1998-11-10

申请号：US880474

申请日：1997-06-23

申请人： Jiang Hsieh

发明人： Jiang Hsieh

IPC分类号： A61B6/03 ,  G06T1/00

CPC分类号： A61B6/032 ,  A61B6/4021 ,  Y10S378/901

摘要： The present invention, in one form, is a system for generating a high resolution image of an object from projection data acquired during a computed tomography scan. The system includes a gantry having an x-ray source which rotates around the object and emits an x-ray beam toward a detector. The system identifies a region of x-ray beam movement and divides the region into subregions. Linear Q-CAL vectors are then generated for each subregion so that each vector is representative of detector gain in one of the subregions. These Q-CAL vectors are then applied to projection data to generate image data.

摘要翻译： 在一种形式中，本发明是一种用于在计算机断层摄影扫描期间从投影数据生成物体的高分辨率图像的系统。 该系统包括具有围绕物体旋转的x射线源并且朝向检测器发射X射线束的台架。 该系统识别X射线束移动的区域，并将该区域划分为子区域。 然后为每个子区域生成线性Q-CAL向量，使得每个向量表示其中一个子区域中的检测器增益。 然后将这些Q-CAL向量应用于投影数据以生成图像数据。

公开(公告)号：US5708690A

公开(公告)日：1998-01-13

申请号：US729435

申请日：1996-10-11

申请人： Jiang Hsieh

发明人： Jiang Hsieh

IPC分类号： G03B42/02 ,  A61B6/03 ,  G06T1/00 ,  G06T11/00

CPC分类号： A61B6/032 ,  G06T11/006 ,  A61B6/027 ,  Y10S378/901

摘要： The present invention, in one form, is a system for performing image reconstruction from projection data acquired in a helical scan. More specifically, the system implements an incremental reconstruction algorithm for helical scan projection data which does not require filtering, weighting and backprojecting such projection data for generating each image. Particularly, an overscan weighting algorithm generates weighting factors to be applied to projection data to generate base image projection data. An update weighting algorithm generates update weighting factors to be applied to the base image projection data to generate subsequent image projection data.

摘要翻译： 本发明以一种形式是用于从螺旋扫描中获取的投影数据执行图像重建的系统。 更具体地，该系统对螺旋扫描投影数据实施增量重建算法，该算法不需要滤波，加权和反投影这种用于生成每个图像的投影数据。 特别地，过扫描加权算法产生要应用于投影数据的加权因子以产生基本图像投影数据。 更新加权算法产生应用于基本图像投影数据的更新加权因子以产生后续图像投影数据。

公开(公告)号：US5533081A

公开(公告)日：1996-07-02

申请号：US373410

申请日：1995-01-17

申请人： Jiang Hsieh

发明人： Jiang Hsieh

IPC分类号： A61B6/03 ,  G01N23/04

CPC分类号： G01N23/046 ,  G01N2223/419 ,  Y10S378/901

摘要： A present invention, in one form, is a method for removing artifacts from image data due to detector degradation. Particularly, data is obtained from a CT system including a detector and an x-ray source. The detector is formed from a plurality of detector cells. In accordance with one form of the invention, a detector degradation signature (S(i)) vector is generated prior to scanning a patient. Subsequent to scanning the patient, if the image data contains a ring error, a detector cell contributing to the error is identified using the detector degradation signature vector. The system then determines if the cell a degraded cell. If such cell is a degraded cell, ring error correction processing is then performed on the image data.

摘要翻译： 以一种形式的本发明是用于由于检测器劣化而从图像数据中去除伪影的方法。 特别地，从包括检测器和X射线源的CT系统获得数据。 检测器由多个检测器单元形成。 根据本发明的一种形式，在扫描患者之前产生检测器降解特征（S（i））矢量。 在扫描患者之后，如果图像数据包含环形误差，则使用检测器劣化特征向量来识别有助于误差的检测器单元。 然后，系统确定细胞是否是降解的细胞。 如果这样的单元是劣化的单元，则对图像数据进行环形纠错处理。

公开(公告)号：US5450461A

公开(公告)日：1995-09-12

申请号：US175905

申请日：1993-12-30

申请人： Jiang Hsieh

发明人： Jiang Hsieh

IPC分类号： A61B6/03 ,  G01N23/04 ,  G01N23/083

CPC分类号： G01N23/046 ,  A61B6/032 ,  G01N2223/419 ,  G01N2223/612 ,  Y10S378/901

摘要： During acquisition of X-ray attenuation measurements of a patient being imaged, the measurements are processed to determine error factors for each detector in the system. In doing so, an average value is calculated for each detector from the X-ray attenuation measurements acquired during a scan of the patient. The set of average values should increase and decrease monotonically going toward and away from the value in the set for center detector. Deviation from such monotonic variation indicates a calibration error and is used to change a calibration factor in the signal processing circuit for the corresponding detector.

摘要翻译： 在获取正在成像的患者的X射线衰减测量期间，处理测量结果以确定系统中每个检测器的误差因子。 在这样做时，根据在患者扫描期间获得的X射线衰减测量值，为每个检测器计算平均值。 平均值的集合应该逐渐增加和减少，单调地朝向和远离中心检测器的集合中的值。 与这种单调变化的偏差表示校准误差，用于改变相应检测器的信号处理电路中的校准因子。

公开(公告)号：US5359638A

公开(公告)日：1994-10-25

申请号：US860659

申请日：1992-03-30

申请人： Jiang Hsieh ,  Robert F. Senzig

发明人： Jiang Hsieh ,  Robert F. Senzig

IPC分类号： A61B6/03 ,  G06T1/00 ,  G06T5/00 ,  G06T11/00 ,  H04N5/32 ,  H04N7/18 ,  G01N23/083

CPC分类号： G06T11/005 ,  A61B6/027 ,  Y10S378/901

摘要： A computed tomography imaging system has a source of radiation and a radiation detector that has an exponential impulse response characterized by a plurality of N components with different time constants. The source and the detector are revolved about an object to be imaged and the output of the detector is sampled periodically to acquire a set of radiation attenuation values, with the values for each revolution being designated as a scan. A recursive filter function is applied sequentially to the radiation attenuation values from a given scan to generate approximated values for variables of the filter function that define residual detector response from the previous scan. A set of filtered attenuation values then is produced by applying the filter function again to the radiation attenuation values from the given scan. The approximated values for variables are used when the filter function is applied to the first radiation attenuation value of the scan. An image is reconstructed from the set of filtered attenuation values.

摘要翻译： 计算机断层成像系统具有辐射源和辐射检测器，其具有由具有不同时间常数的多个N个分量表征的指数脉冲响应。 源和检测器围绕要成像的物体旋转，并且周期性地采样检测器的输出以获得一组辐射衰减值，每个旋转的值被指定为扫描。 递归滤波器函数被顺序地应用于来自给定扫描的辐射衰减值，以产生用于定义来自先前扫描的残余检测器响应的滤波器函数的变量的近似值。 然后通过将滤波器函数再次应用于来自给定扫描的辐射衰减值来产生一组经滤波的衰减值。 当滤波器函数应用于扫描的第一个辐射衰减值时，使用变量的近似值。 从滤波的衰减值的集合重建图像。

公开(公告)号：US4823017A

公开(公告)日：1989-04-18

申请号：US944700

申请日：1986-12-19

申请人： Jiang Hsieh

发明人： Jiang Hsieh

IPC分类号： G01T1/161 ,  A61B6/03 ,  G01T1/164 ,  G03B15/00 ,  G21K1/02

CPC分类号： G01T1/1642 ,  G21K1/025 ,  A61B6/037

摘要： A fan-beam collimator has a plurality of focal lengths. The shortest focal length is located at the center of the collimator. The longest focal length is located at the periphery of the collimator. The focal length increases between the minimum focal length and the maximum focal length.

摘要翻译： 扇形光束准直仪具有多个焦距。 最短焦距位于准直仪的中心。 最长的焦距位于准直仪的外围。 焦距在最小焦距和最大焦距之间增加。