The Experts below are selected from a list of 3258 Experts worldwide ranked by ideXlab platform

Yuan Xu - One of the best experts on this subject based on the ideXlab platform.

  • john s equation based consistency condition and corrupted projection restoration in Circular Trajectory cone beam ct
    Scientific Reports, 2017
    Co-Authors: Shuyu Wu, Hongliang Qi, Bin Li, Linghong Zhou, Yuan Xu
    Abstract:

    In transmitted X-ray tomography imaging, the acquired projections may be corrupted for various reasons, such as defective detector cells and beam-stop array scatter correction problems. In this study, we derive a consistency condition for cone-beam projections and propose a method to restore lost data in corrupted projections. In particular, the relationship of the geometry parameters in Circular Trajectory cone-beam computed tomography (CBCT) is utilized to convert an ultra-hyperbolic partial differential equation (PDE) into a second-order PDE. The second-order PDE is then transformed into a first-order ordinary differential equation in the frequency domain. The left side of the equation for the newly derived consistency condition is the projection derivative of the current and adjacent views, whereas the right side is the projection derivative of the geometry parameters. A projection restoration method is established based on the newly derived equation to restore corrupted data in projections in Circular Trajectory CBCT. The proposed method is tested in beam-stop array scatter correction, metal artifact reduction, and abnormal pixel correction cases to evaluate the performance of the consistency condition and corrupted projection restoration method. Qualitative and quantitative results demonstrate that the present method has considerable potential in restoring lost data in corrupted projections.

  • John?s Equation-based Consistency Condition and Corrupted Projection Restoration in Circular Trajectory Cone Beam CT
    Scientific Reports, 2017
    Co-Authors: Jianhui Ma, Shuyu Wu, Hongliang Qi, Bin Li, Linghong Zhou, Yuan Xu
    Abstract:

    In transmitted X-ray tomography imaging, the acquired projections may be corrupted for various reasons, such as defective detector cells and beam-stop array scatter correction problems. In this study, we derive a consistency condition for cone-beam projections and propose a method to restore lost data in corrupted projections. In particular, the relationship of the geometry parameters in Circular Trajectory cone-beam computed tomography (CBCT) is utilized to convert an ultra-hyperbolic partial differential equation (PDE) into a second-order PDE. The second-order PDE is then transformed into a first-order ordinary differential equation in the frequency domain. The left side of the equation for the newly derived consistency condition is the projection derivative of the current and adjacent views, whereas the right side is the projection derivative of the geometry parameters. A projection restoration method is established based on the newly derived equation to restore corrupted data in projections in Circular Trajectory CBCT. The proposed method is tested in beam-stop array scatter correction, metal artifact reduction, and abnormal pixel correction cases to evaluate the performance of the consistency condition and corrupted projection restoration method. Qualitative and quantitative results demonstrate that the present method has considerable potential in restoring lost data in corrupted projections.

Linghong Zhou - One of the best experts on this subject based on the ideXlab platform.

  • john s equation based consistency condition and corrupted projection restoration in Circular Trajectory cone beam ct
    Scientific Reports, 2017
    Co-Authors: Shuyu Wu, Hongliang Qi, Bin Li, Linghong Zhou, Yuan Xu
    Abstract:

    In transmitted X-ray tomography imaging, the acquired projections may be corrupted for various reasons, such as defective detector cells and beam-stop array scatter correction problems. In this study, we derive a consistency condition for cone-beam projections and propose a method to restore lost data in corrupted projections. In particular, the relationship of the geometry parameters in Circular Trajectory cone-beam computed tomography (CBCT) is utilized to convert an ultra-hyperbolic partial differential equation (PDE) into a second-order PDE. The second-order PDE is then transformed into a first-order ordinary differential equation in the frequency domain. The left side of the equation for the newly derived consistency condition is the projection derivative of the current and adjacent views, whereas the right side is the projection derivative of the geometry parameters. A projection restoration method is established based on the newly derived equation to restore corrupted data in projections in Circular Trajectory CBCT. The proposed method is tested in beam-stop array scatter correction, metal artifact reduction, and abnormal pixel correction cases to evaluate the performance of the consistency condition and corrupted projection restoration method. Qualitative and quantitative results demonstrate that the present method has considerable potential in restoring lost data in corrupted projections.

  • John?s Equation-based Consistency Condition and Corrupted Projection Restoration in Circular Trajectory Cone Beam CT
    Scientific Reports, 2017
    Co-Authors: Jianhui Ma, Shuyu Wu, Hongliang Qi, Bin Li, Linghong Zhou, Yuan Xu
    Abstract:

    In transmitted X-ray tomography imaging, the acquired projections may be corrupted for various reasons, such as defective detector cells and beam-stop array scatter correction problems. In this study, we derive a consistency condition for cone-beam projections and propose a method to restore lost data in corrupted projections. In particular, the relationship of the geometry parameters in Circular Trajectory cone-beam computed tomography (CBCT) is utilized to convert an ultra-hyperbolic partial differential equation (PDE) into a second-order PDE. The second-order PDE is then transformed into a first-order ordinary differential equation in the frequency domain. The left side of the equation for the newly derived consistency condition is the projection derivative of the current and adjacent views, whereas the right side is the projection derivative of the geometry parameters. A projection restoration method is established based on the newly derived equation to restore corrupted data in projections in Circular Trajectory CBCT. The proposed method is tested in beam-stop array scatter correction, metal artifact reduction, and abnormal pixel correction cases to evaluate the performance of the consistency condition and corrupted projection restoration method. Qualitative and quantitative results demonstrate that the present method has considerable potential in restoring lost data in corrupted projections.

  • cone beam ct reconstruction based on Circular scan Trajectory and ring artifact reduction
    Journal of Southern Medical University, 2009
    Co-Authors: Jun Yang, Xin Zhen, Wenting Lu, Linghong Zhou
    Abstract:

    OBJECTIVE: The FDK algorithm is one of the most widely used algorithms for cone-beam CT reconstruction in Circular Trajectory due to its simplicity of implementation and computational efficiency. However, the images reconstructed by the FDK algorithm based on real projection data may be blurred without electronic correction and geometric calibration, and are often plagued by deleterious ring artifacts and shading artifacts. We compared the images reconstructed with and without detector correction based on computer experiment of the real biological object. The experimental simulation shows that these algorithms are effective in reducing the ring artifact without compromising the image resolution, and produce satisfactory results.

Shihua Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Circular Trajectory reconstruction uncovers cell cycle progression and regulatory dynamics from single cell hi c maps
    Advanced Science, 2019
    Co-Authors: Yusen Ye, Shihua Zhang
    Abstract:

    : Single-cell Hi-C technology is emerging and will provide unprecedented opportunities to elucidate chromosomal dynamics with high resolution. How to characterize pseudo time-series of single cells using single-cell Hi-C maps is an essential and challenging topic. To this end, a powerful Circular Trajectory reconstruction tool CIRCLET is developed to resolve cell cycle phases of single cells by considering multiscale features of chromosomal architectures without specifying a starting cell. CIRCLET reveals its best superiority based on the combination of one feature set about global information and another two feature sets about local interactional information in terms of designed evaluation indexes and verification strategies from a collection of cell-cycle Hi-C maps of 1171 single cells. Further division of the reconstructed Trajectory into 12 stages helps to accurately characterize the dynamics of chromosomal structures and explain the special regulatory events along cell-cycle progression. Last but not the least, the reconstructed Trajectory helps to uncover important regulatory genes related with dynamic substructures, providing a novel framework for discovering regulatory regions even cancer markers at single-cell resolution.

Shuyu Wu - One of the best experts on this subject based on the ideXlab platform.

  • john s equation based consistency condition and corrupted projection restoration in Circular Trajectory cone beam ct
    Scientific Reports, 2017
    Co-Authors: Shuyu Wu, Hongliang Qi, Bin Li, Linghong Zhou, Yuan Xu
    Abstract:

    In transmitted X-ray tomography imaging, the acquired projections may be corrupted for various reasons, such as defective detector cells and beam-stop array scatter correction problems. In this study, we derive a consistency condition for cone-beam projections and propose a method to restore lost data in corrupted projections. In particular, the relationship of the geometry parameters in Circular Trajectory cone-beam computed tomography (CBCT) is utilized to convert an ultra-hyperbolic partial differential equation (PDE) into a second-order PDE. The second-order PDE is then transformed into a first-order ordinary differential equation in the frequency domain. The left side of the equation for the newly derived consistency condition is the projection derivative of the current and adjacent views, whereas the right side is the projection derivative of the geometry parameters. A projection restoration method is established based on the newly derived equation to restore corrupted data in projections in Circular Trajectory CBCT. The proposed method is tested in beam-stop array scatter correction, metal artifact reduction, and abnormal pixel correction cases to evaluate the performance of the consistency condition and corrupted projection restoration method. Qualitative and quantitative results demonstrate that the present method has considerable potential in restoring lost data in corrupted projections.

  • John?s Equation-based Consistency Condition and Corrupted Projection Restoration in Circular Trajectory Cone Beam CT
    Scientific Reports, 2017
    Co-Authors: Jianhui Ma, Shuyu Wu, Hongliang Qi, Bin Li, Linghong Zhou, Yuan Xu
    Abstract:

    In transmitted X-ray tomography imaging, the acquired projections may be corrupted for various reasons, such as defective detector cells and beam-stop array scatter correction problems. In this study, we derive a consistency condition for cone-beam projections and propose a method to restore lost data in corrupted projections. In particular, the relationship of the geometry parameters in Circular Trajectory cone-beam computed tomography (CBCT) is utilized to convert an ultra-hyperbolic partial differential equation (PDE) into a second-order PDE. The second-order PDE is then transformed into a first-order ordinary differential equation in the frequency domain. The left side of the equation for the newly derived consistency condition is the projection derivative of the current and adjacent views, whereas the right side is the projection derivative of the geometry parameters. A projection restoration method is established based on the newly derived equation to restore corrupted data in projections in Circular Trajectory CBCT. The proposed method is tested in beam-stop array scatter correction, metal artifact reduction, and abnormal pixel correction cases to evaluate the performance of the consistency condition and corrupted projection restoration method. Qualitative and quantitative results demonstrate that the present method has considerable potential in restoring lost data in corrupted projections.

Alain Berthoz - One of the best experts on this subject based on the ideXlab platform.

  • Circular Trajectory formation during blind locomotion a test for path integration and motor memory
    Experimental Brain Research, 1997
    Co-Authors: Yasuhiko Takei, Renato Grasso, Michelange Amorim, Alain Berthoz
    Abstract:

    Eight healthy subjects were asked to walk blindfolded along Circular paths of different radii after several practice trials with vision. Their task was to stop after completing two full revolutions. They always walked counter-clockwise (CCW) in (a) a control condition (CONTROL), including the instructions mentioned above, (b) with the further instruction to count backwards in twos (MENTAL), (c) with the instruction to count loudly (LOUD). The movement of two markers lying along the head naso-occipital axis was recorded by means of an ELITE system. Total walked distance (DISTANCE), total head turning angle (ANGLE) and average radius (RADIUS) of the trajectories performed were measured. All subjects were able to perform approximately Circular trajectories. They consistently overshot the ideal radius independently of the condition and circle size, undershot the total angle and overshot total distance. The LOUD condition induced greater errors in the performance but only on total distance (P<0.05). A strong correlation was found between the errors in radius and total distance but not between distance and total angle. Principal components analysis suggested that radius and distance share a common source of errors while total angle produced independent errors. The results indicate that (a) Circular trajectories can be generated starting from spatial and/or motor memory, without the aid of visual information; (b) the task needs some attentional control and does not involve simple automatic processing of afferent information; (c) different sensory information or different processing modes are probably involved in the estimation of the curvature and length of the walked path on the one hand, and of the total rotation angle on the other.

  • Circular Trajectory formation during blind locomotion: a test for path integration and motor memory.
    Experimental Brain Research, 1997
    Co-Authors: Yasuhiko Takei, Renato Grasso, Michelange Amorim, Alain Berthoz
    Abstract:

    Eight healthy subjects were asked to walk blindfolded along Circular paths of different radii after several practice trials with vision. Their task was to stop after completing two full revolutions. They always walked counter-clockwise (CCW) in (a) a control condition (CONTROL), including the instructions mentioned above, (b) with the further instruction to count backwards in twos (MENTAL), (c) with the instruction to count loudly (LOUD). The movement of two markers lying along the head naso-occipital axis was recorded by means of an ELITE system. Total walked distance (DISTANCE), total head turning angle (ANGLE) and average radius (RADIUS) of the trajectories performed were measured. All subjects were able to perform approximately Circular trajectories. They consistently overshot the ideal radius independently of the condition and circle size, undershot the total angle and overshot total distance. The LOUD condition induced greater errors in the performance but only on total distance (P