Motion Compensated X-ray CT Algorithm for Moving Objects

2011 ◽  
Author(s):  
Takumi Tanaka ◽  
Shin-ichi Maeda ◽  
Shin Ishii
Keyword(s):  
Moving Objects ◽  
X Ray

Determination of strain in moving objects by X-ray diffraction using synchrotron radiation

1988 ◽  
Vol 21 (6) ◽  
pp. 972-974 ◽  
Author(s):  
J. Ihringer ◽  
T. Wroblewski ◽  
A. Küster ◽  
J. K. Maichle
Keyword(s):  
Synchrotron Radiation ◽  
Moving Objects ◽  
X Ray Diffraction ◽  
X Ray

X-ray imaging of moving objects using on-chip TDI and MDX methods with single photon counting CdTe hybrid pixel detector

2021 ◽  
Vol 16 (12) ◽  
pp. C12014
Author(s):  
M. Zoladz ◽  
P. Grybos ◽  
R. Szczygiel
Keyword(s):  
Moving Objects ◽  
Single Photon ◽  
Photon Counting ◽  
Two Dimensional ◽  
Single Photon Counting ◽  
X Ray ◽  
X Ray Imaging ◽  
On Chip ◽  
Pixel Matrix ◽  
Single Pixel

Abstract X-ray imaging of moving objects using line detectors remains the most popular method of object content and structure examination with a typical resolution limited to 0.4–1 mm. Higher resolutions are difficult to obtain as, for the detector in the form of a single pixel row, the narrower the detector is, the lower the image Signal to Noise Ratio (SNR). This is because, for smaller pixel sizes, fewer photons hit the pixel in each time unit for a given radiation intensity. To overcome the trade-off between the SNR and spatial resolution, a two-dimensional sensor, namely a pixel matrix can be used. Imaging of moving objects with a pixel matrix requires time-domain integration (TDI). Straightforward TDI implementation is based on the proper accumulation of images acquired during consecutive phases of an object’s movement. Unfortunately, this method is much more demanding regarding data transfer and processing. Data from the whole pixel matrix instead of a single pixel row must be transferred out of the chip and then processed. The alternative approach is on-chip TDI implementation. It takes advantage of photons acquired by multiple rows (a higher SNR), but generates similar data amount as a single pixel row and does not require data processing out of the chip. In this paper, on-chip TDI is described and verified by using a single photon counting two-dimensional (a matrix of 128 × 192 pixels) CdTe hybrid X-ray detector with the 100 µm × 100 µm pixel size with up to four energy thresholds per pixel. Spatial resolution verification is combined with the Material Discrimination X-ray (MDX) imaging method.

X‐ray diffraction by moving objects: A new application of synchrotron radiation

1989 ◽  
Vol 60 (7) ◽  
pp. 2354-2355 ◽  
Author(s):  
J. Ihringer ◽  
T. Wroblewski
Keyword(s):  
Synchrotron Radiation ◽  
Moving Objects ◽  
X Ray Diffraction ◽  
X Ray

Influence of x-ray pulse parameters on the image quality for moving objects in digital cardiac imaging

2004 ◽  
Vol 31 (10) ◽  
pp. 2819-2825 ◽  
Author(s):  
Eduardo Guibelalde ◽  
Eliseo Vano ◽  
Francisco Vaquero ◽  
Luciano González
Keyword(s):  
Image Quality ◽  
Cardiac Imaging ◽  
Moving Objects ◽  
X Ray ◽  
Pulse Parameters

scholarly journals Real-time algorithm for Poissonian noise reduction in low-dose fluoroscopy: performance evaluation

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
A. Sarno ◽  
E. Andreozzi ◽  
D. De Caro ◽  
G. Di Meo ◽  
A. G. M. Strollo ◽  
...  
Keyword(s):  
Image Quality ◽  
Real Time ◽  
Video Processing ◽  
Moving Objects ◽  
Quantum Noise ◽  
Moving Average ◽  
Threshold Level ◽  
Computational Time ◽  
X Ray ◽  
Mask Size

Abstract Background Quantum noise intrinsically limits the quality of fluoroscopic images. The lower is the X-ray dose the higher is the noise. Fluoroscopy video processing can enhance image quality and allows further patient’s dose lowering. This study aims to assess the performances achieved by a Noise Variance Conditioned Average (NVCA) spatio-temporal filter for real-time denoising of fluoroscopic sequences. The filter is specifically designed for quantum noise suppression and edge preservation. It is an average filter that excludes neighborhood pixel values exceeding noise statistic limits, by means of a threshold which depends on the local noise standard deviation, to preserve the image spatial resolution. The performances were evaluated in terms of contrast-to-noise-ratio (CNR) increment, image blurring (full width of the half maximum of the line spread function) and computational time. The NVCA filter performances were compared to those achieved by simple moving average filters and the state-of-the-art video denoising block matching-4D (VBM4D) algorithm. The influence of the NVCA filter size and threshold on the final image quality was evaluated too. Results For NVCA filter mask size of 5 × 5 × 5 pixels (the third dimension represents the temporal extent of the filter) and a threshold level equal to 2 times the local noise standard deviation, the NVCA filter achieved a 10% increase of the CNR with respect to the unfiltered sequence, while the VBM4D achieved a 14% increase. In the case of NVCA, the edge blurring did not depend on the speed of the moving objects; on the other hand, the spatial resolution worsened of about 2.2 times by doubling the objects speed with VBM4D. The NVCA mask size and the local noise-threshold level are critical for final image quality. The computational time of the NVCA filter was found to be just few percentages of that required for the VBM4D filter. Conclusions The NVCA filter obtained a better image quality compared to simple moving average filters, and a lower but comparable quality when compared with the VBM4D filter. The NVCA filter showed to preserve edge sharpness, in particular in the case of moving objects (performing even better than VBM4D). The simplicity of the NVCA filter and its low computational burden make this filter suitable for real-time video processing and its hardware implementation is ready to be included in future fluoroscopy devices, offering further lowering of patient’s X-ray dose.

scholarly journals Interface Measurement of Moving Objects by Using a Fast X-ray CT Scanner

2001 ◽  
Vol 21 (2) ◽  
pp. 38-44 ◽  
Author(s):  
Masaki Misawa ◽  
Naoki Takada ◽  
Naoki Ichikawa ◽  
Makoto Akai
Keyword(s):  
Moving Objects ◽  
Ct Scanner ◽  
X Ray

Pulsed X-ray source with the pulse duration of 50 ns and the peak power of 70 MW for capturing moving objects

2021 ◽  
pp. 1-10
Author(s):  
Alexander Alexandrovich Komarskiy ◽  
Sergey Romanovich Korzhenevskiy ◽  
Andrey Viktorovich Ponomarev ◽  
Nikita Alexandrovich Komarov
Keyword(s):  
Pulse Duration ◽  
Repetition Rate ◽  
Pulse Repetition Rate ◽  
Moving Objects ◽  
Frame Rate ◽  
Pulse Repetition ◽  
Storage Device ◽  
Semiconductor Detectors ◽  
X Rays ◽  
X Ray

BACKGROUND: Traditionally, X-ray systems for capturing moving objects consist of a continuous X-ray source and a detector that operates at a predetermined frame rate. OBJECTIVE: This study investigates the possibility of using pulsed X-ray source with an inductive energy storage device and a semiconductor opening switch for shooting moving objects. METHODS: The study uses a high-voltage pulse generator that has the following parameters namely, the pulse voltage amplitude up to 320 kV, the pulse current up to 240 A, the current pulse duration of about 50 ns, and the pulse repetition rate up to 2 kHz. The duration and intensity of glow for standard CsI:Tl and Gd2O2S:Tb X-ray phosphors after their irradiation with X-ray flashes of about 50 ns duration are investigated. After X-ray radiation is converted into light, the signal is recorded using semiconductor detectors. We acquired several images of an object moving at a speed of about 20 m/s. A semiconductor detector with phosphor, which operates in the mode of continuous signal accumulation, is used. RESULTS: When using the pulsed X-ray source and phosphors with a short afterglow, the individual frames can be obtained at the pulse repetition rate of several kilohertz, and the detector does not contain the residual luminescence from the previous frame by the arrival of the next frame. CONCLUSIONS: The X-ray source shows good pulse-to-pulse reproducibility of X-rays, and can be used to capture objects in motion at a frame rate of several kHz.

Detection of moving objects in pulsed-x-ray fluoroscopy

1998 ◽  
Vol 15 (2) ◽  
pp. 375 ◽  
Author(s):  
Ping Xue ◽  
David L. Wilson
Keyword(s):  
Moving Objects ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document