scholarly journals AN AUTOMATIC ICP-BASED 2D-3D REGISTRATION METHOD FOR A HIGH-SPEED BIPLANAR VIDEORADIOGRAPHY IMAGING SYSTEM

2020 ◽  
Vol XLIII-B2-2020 ◽  
pp. 805-812
Author(s):  
S. Zhang ◽  
D. D. Lichti ◽  
J. C. Küpper ◽  
J. L. Ronsky
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Imaging System ◽  
Ct Scans ◽  
3D Registration ◽  
Kinematic Parameters ◽  
Registration Method ◽  
X Ray ◽  
Automatic Initialization ◽  
Image Pairs

Abstract. High-Speed Biplanar Videoradiography (HSBV) is an X-ray based non-invasive imaging system that can be used to derive dynamic bony translations and rotations. The 2D-3D registration process matches a 3D bone model acquired from magnetic resonance imaging (MRI) or computed tomography (CT) scans with the 2D X-ray image pairs. This study focuses on the registration of MRI data as it can acquire detailed soft tissue contrast that cannot be easily discerned in CT scans. A novel 2D-3D registration method is reported in this paper that is suitable for the MRI-based bone models with high precision and high efficiency. In addition, an automatic initialization procedure with 64 starting poses is established to avoid user intervention in the registration. The method has been tested using the HSBV image sequence of a knee joint during walking. Thirty-five consecutive poses from the sequence were tested for the registration, and 50 non-consecutive poses randomly selected from the sequence were tested for the automatic initialization. The registration precision for each axis was 0.49 to 0.54 mm. For the initialization validation test, 48 over 50 frames were successfully initialized and two failed due to portions of the joint falling outside of the field-of-view of the system. The average time for each initialization is only about 6 min. The improved 2D-3D registration will allow determination of precise 3D kinematic parameters with high efficiency. These kinematic parameters can be used to calculate joint cartilage contact mechanics that provide insight into the mechanical processes and mechanisms of joint degeneration or pathology.

High-efficiency fast X-ray imaging detector development at SSRF

2019 ◽  
Vol 26 (5) ◽  
pp. 1631-1637
Author(s):  
Honglan Xie ◽  
Hongxin Luo ◽  
Guohao Du ◽  
Chengqiang Zhao ◽  
Wendong Xu ◽  
...  
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Sampling Rate ◽  
Coupling Efficiency ◽  
Numerical Aperture ◽  
X Ray ◽  
Temporal Sampling ◽  
X Ray Imaging ◽  
Imaging Detector ◽  
Working Distance

Indirect X-ray imaging detectors consisting of scintillator screens, long-working-distance microscope lenses and scientific high-speed complementary metal-oxide semiconductor (CMOS) cameras are usually used to realize fast X-ray imaging with white-beam synchrotron radiation. However, the detector efficiency is limited by the coupling efficiency of the long-working-distance microscope lenses, which is only about 5%. A long-working-distance microscope lenses system with a large numerical aperture (NA) is designed to increase the coupling efficiency. It offers an NA of 0.5 at 8× magnification. The Mitutoyo long-working-distance microscope lenses system offers an NA of 0.21 at 7.5× magnification. Compared with the Mitutoyo system, the developed long-working-distance microscope lenses system offers about twice the NA and four times the coupling efficiency. In the indirect X-ray imaging detector, a 50 µm-thick LuAG:Ce scintillator matching with the NA, and a high-speed visible-light CMOS FastCAM SAZ Photron camera are used. Test results show that the detector realized fast X-ray imaging with a frame rate of 100000 frames s−1 and fast X-ray microtomography with a temporal sampling rate up to 25 Hz (25 tomograms s−1).

Validation of a New Method for 2D Fusion Imaging Registration in a System Prepared Only for 3D

2020 ◽  
Vol 27 (3) ◽  
pp. 468-472
Author(s):  
Andreas Edsfeldt ◽  
Björn Sonesson ◽  
Helena Rosén ◽  
Marcelo H. Petri ◽  
Kiattisak Hongku ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Radiation Exposure ◽  
Imaging System ◽  
Endovascular Aneurysm Repair ◽  
Fusion Imaging ◽  
Operating Table ◽  
3D Registration ◽  
Registration Method ◽  
Dose Area Product ◽  
Single Frame

Purpose: To validate a new 2D-3D registration method of fusion imaging during aortic repair in a system prepared only for 3D-3D registration and to compare radiation doses and accuracy. Materials and Methods: The study involved 189 patients, including 94 patients (median age 70 years; 85 men) who underwent abdominal endovascular aneurysm repair (EVAR) with 2D-3D fusion on an Artis zee imaging system and 95 EVAR patients (median age 70 years; 81 men) from a prior study who had 3D-3D registration done using cone beam computed tomography (CBCT). For the 2D-3D registration, an offline CBCT of the empty operating table was imported into the intraoperative dataset and superimposed on the preoperative computed tomography angiogram (CTA). Then 2 intraoperative single-frame 2D images of the skeleton were aligned with the patient’s skeleton on the preoperative CTA to complete the registration process. A digital subtraction angiogram was done to correct any misalignment of the aortic CTA volume. Values are given as the median [interquartile range (IQR) Q1, Q3]. Results: The 2D-3D registration had an accuracy of 4.0 mm (IQR 3.0, 5.0) after bone matching compared with the final correction with DSA (78% within 5 mm). By applying the 2D-3D protocol the radiation exposure (dose area product) from the registration of the fusion image was significantly reduced compared with the 3D-3D registration [1.12 Gy∙cm2 (IQR 0.41, 2.14) vs 43.4 Gy∙cm2 (IQR 37.1, 49.0), respectively; p<0.001). Conclusion: The new 2D-3D registration protocol based on 2 single-frame images avoids an intraoperative CBCT and can be used for fusion imaging registration in a system originally designed for 3D-3D only. This 2D-3D registration protocol is accurate and leads to a significant reduction in radiation exposure.

scholarly journals Quantitative 4D X-ray microtomography under extreme conditions: a case study on magma migration

2021 ◽  
Vol 28 (5) ◽  
Author(s):  
Elena Giovenco ◽  
Jean-Philippe Perrillat ◽  
Eglantine Boulard ◽  
Andrew King ◽  
Nicolas Guignot ◽  
...  
Keyword(s):  
Computed Tomography ◽  
High Pressure ◽  
High Temperature ◽  
High Speed ◽  
High Efficiency ◽  
Morphological Properties ◽  
Extreme Conditions ◽  
Temporal Dimension ◽  
Angular Aperture ◽  
X Ray

X-ray computed tomography (XCT) is a well known method for three-dimensional characterization of materials that is established as a powerful tool in high-pressure/high-temperature research. The optimization of synchrotron beamlines and the development of fast high-efficiency detectors now allow the addition of a temporal dimension to tomography studies under extreme conditions. Presented here is the experimental setup developed on the PSICHE beamline at SOLEIL to perform high-speed XCT in the Ultra-fast Tomography Paris–Edinburgh cell (UToPEc). The UToPEc is a compact panoramic (165° angular aperture) press optimized for fast tomography that can access 10 GPa and 1700°C. It is installed on a high-speed rotation stage (up to 360° s−1) and allows the acquisition of a full computed tomography (CT) image with micrometre spatial resolution within a second. This marks a major technical breakthrough for time-lapse XCT and the real-time visualization of evolving dynamic systems. In this paper, a practical step-by-step guide to the use of the technique is provided, from the collection of CT images and their reconstruction to performing quantitative analysis, while accounting for the constraints imposed by high-pressure and high-temperature experimentation. The tomographic series allows the tracking of key topological parameters such as phase fractions from 3D volumetric data, and also the evolution of morphological properties (e.g. volume, flatness, dip) of each selected entity. The potential of this 4D tomography is illustrated by percolation experiments of carbonate melts within solid silicates, relevant for magma transfers in the Earth's mantle.

scholarly journals Ultra-high-speed indirect x-ray imaging system with versatile spatiotemporal sampling capabilities

2018 ◽  
Vol 57 (18) ◽  
pp. 5004 ◽  
Author(s):  
Emilio M. Escauriza ◽  
Margie P. Olbinado ◽  
Michael E. Rutherford ◽  
David J. Chapman ◽  
John C. Z. Jonsson ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging System ◽  
X Ray ◽  
Ultra High Speed ◽  
X Ray Imaging

scholarly journals Development of an X-ray imaging system to prevent scintillator degradation for white synchrotron radiation

2018 ◽  
Vol 25 (3) ◽  
pp. 801-807 ◽  
Author(s):  
Tunhe Zhou ◽  
Hongchang Wang ◽  
Thomas Connolley ◽  
Steward Scott ◽  
Nick Baker ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging System ◽  
Dust Particles ◽  
Light Sources ◽  
Contrast Imaging ◽  
X Ray ◽  
X Ray Imaging ◽  
Synchrotron Light ◽  
Cost Efficient ◽  
Synchrotron Light Sources

The high flux of the white X-ray beams from third-generation synchrotron light sources can significantly benefit the development of high-speed X-ray imaging, but can also bring technical challenges to existing X-ray imaging systems. One prevalent problem is that the image quality deteriorates because of dust particles accumulating on the scintillator screen during exposure to intense X-ray radiation. Here, this problem has been solved by embedding the scintillator in a flowing inert-gas environment. It is also shown that the detector maintains the quality of the captured images even after days of X-ray exposure. This modification is cost-efficient and easy to implement. Representative examples of applications using the X-ray imaging system are also provided, including fast tomography and multimodal phase-contrast imaging for biomedical and geological samples.

scholarly journals Quantitative analysis of dribble volumes and rates using three-dimensional reconstruction of X-ray and diffused back-illumination images of diesel sprays

2019 ◽  
Vol 21 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Vitaliy Sechenyh ◽  
Daniel J Duke ◽  
Andrew B Swantek ◽  
Katarzyna E Matusik ◽  
Alan L Kastengren ◽  
...  
Keyword(s):  
High Speed ◽  
Imaging System ◽  
Process Analysis ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Injection Pressure ◽  
X Ray ◽  
Temperature Conditions ◽  
Processing Approach ◽  
Wide Range

Post-injection fuel dribble is known to lead to incomplete atomisation and combustion due to the release of slow-moving, and often surface-bound, liquid fuel after the end of injection. This can have a negative effect on engine emissions, performance and injector durability. To better quantify this phenomenon, we developed an image-processing approach to measure the volume of ligaments produced during the end of injection. We applied our processing approach to an Engine Combustion Network ‘Spray B’ 3-hole injector, using datasets from 220 injections generated by different research groups, to decouple the effect of gas temperature and pressure on the fuel dribble process. High-speed X-ray phase-contrast images obtained at room temperature conditions (297 K) at the Advanced Photon Source at Argonne National Laboratory, together with diffused back-illumination images captured at a wide range of temperature conditions (293–900 K) by CMT Motores Térmicos were analysed and compared quantitatively. We found a good agreement between image sets obtained by Argonne National Laboratory and CMT Motores Térmicos using different imaging techniques. The maximum dribble volume within the field of view of the imaging system and the mean rate of fuel dribble were considered as characteristic parameters of the fuel dribble process. Analysis showed that the absolute mean dribble rate increases with temperature when injection pressure is higher than 1000 bar and slightly decreases at high injection pressures (>500 bar) when temperature is close to 293 K. Larger maximum volumes of the fuel dribble were observed at lower gas temperatures (∼473 K) and low gas pressures (<30 bar), with a slight dependence on injection pressure.

scholarly journals ITK-Based Implementation of Two-Projection 2D/3D Registration Method with an Application in Patient Setup for External Beam Radiotherapy

2010 ◽  
Author(s):  
Jian Wu
Keyword(s):  
Imaging System ◽  
External Beam Radiotherapy ◽  
Optimization Method ◽  
External Beam ◽  
3D Image ◽  
3D Registration ◽  
Registration Method ◽  
Projection Images ◽  
Patient Setup ◽  
Image Volume

This document describes an ITK-based implementation of intensity-based 2D/3D rigid image registration for patient setup assessment in external beam radiotherapy. The registration framework was designed to simultaneously register two projection images to a 3D image volume. The projection geometry was set up to simulate the x-ray imaging system that attached to a medical linear accelerator for cancer treatment. The normalized correlation was used as the similarity measure and the Powell’s optimizer was used as the optimization method. Siddon-Jacobs fast ray-tracing algorithm was implemented to compute projection images from a 3D image volume.

Spectral Microscopy Imaging System for High-Resolution and High-Speed Imaging of Fuel Sprays

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Ken Maassen ◽  
Farzad Poursadegh ◽  
Caroline Genzale
Keyword(s):  
High Resolution ◽  
High Speed ◽  
High Pressures ◽  
High Efficiency ◽  
Imaging System ◽  
Direct Injection ◽  
Resolving Power ◽  
Microscopy Imaging ◽  
Fuel Sprays ◽  
Primary Breakup

Abstract Modern high-efficiency engines utilize direct injection for charge preparation at extremely high pressures. At these conditions, the scales of atomization become challenging to measure, as primary breakup occurs on the micrometer and nanosecond scales. As such, fuel sprays at these conditions have proven difficult to study via direct imaging. While high-speed cameras now exist that can shutter at tens to hundreds of nanoseconds, and long-range microscopes can be coupled to these cameras to provide high-resolution images, the resolving power of these systems is typically limited by pixel size and field of view (FOV). The large pixel sizes make the realization of the diffraction-limited optical resolution quite challenging. On the other hand, limited data throughput under high repetition rate operation limits the FOV due to reduced sensor area. Therefore, a novel measurement technique is critical to study fuel spray formation at engine-relevant conditions. In this work, we demonstrate a new high-resolution imaging technique, spectral microscopy, which aims to realize diffraction-limited imaging at effective framerates sufficient for capturing primary breakup in engine-relevant sprays. A spectral microscopy system utilizing a consumer-grade DSLR allows for significantly wider FOV with improved resolving power compared to high-speed cameras. Temporal shuttering is accomplished via separate and independently triggered back illumination sources, with wavelengths selected to overlap with the detection bands of the camera sensor's RGB filter array. The RGB detection channels act as filters to capture independently timed red, green, and blue light pulses, enabling the capture of a three consecutive images at effective framerates exceeding 20 × 106 fps. To optimize system performance, a backlit illumination system is designed to maximize light throughput, a multilens setup is created, and an image-processing algorithm is demonstrated that formulates a three-frame image from the camera sensor. The system capabilities are then demonstrated by imaging engine relevant diesel sprays. The spectral microscopy system detailed in this paper allows for micron-scale feature recognition at framerates exceeding 20 × 106 fps, thus expanding the capability for experimental research on primary breakup in fuel sprays for modern direct-injection engines.

High-speed x-ray imaging system for the investigation of laser welding processes

2019 ◽  
Vol 31 (4) ◽  
pp. 042004 ◽  
Author(s):  
Meiko Boley ◽  
Florian Fetzer ◽  
Rudolf Weber ◽  
Thomas Graf
Keyword(s):  
Laser Welding ◽  
High Speed ◽  
Imaging System ◽  
X Ray ◽  
X Ray Imaging ◽  
Welding Processes
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