Effects of dead time on quantitative dual-energy imaging using a position-sensitive spectroscopic detector

2017 ◽  
Author(s):  
Louise M. Dummott ◽  
Giuseppe Schettino ◽  
Paul Seller ◽  
Matthew D. Wilson ◽  
Matthew C. Veale ◽  
...  
Keyword(s):  
Dead Time ◽  
Dual Energy ◽  
Dual Energy Imaging ◽  
Position Sensitive

Material Identification in Presence of Metal for Baggage Screening

2020 ◽  
Vol 2020 (14) ◽  
pp. 294-1-294-8
Author(s):  
Sandamali Devadithya ◽  
David Castañón
Keyword(s):  
Atomic Number ◽  
Effective Atomic Number ◽  
Simulated Data ◽  
Dual Energy ◽  
Basis Functions ◽  
Total Variation Regularization ◽  
Ct Scanner ◽  
Edge Preserving ◽  
Baggage Screening ◽  
Dual Energy Imaging

Dual-energy imaging has emerged as a superior way to recognize materials in X-ray computed tomography. To estimate material properties such as effective atomic number and density, one often generates images in terms of basis functions. This requires decomposition of the dual-energy sinograms into basis sinograms, and subsequently reconstructing the basis images. However, the presence of metal can distort the reconstructed images. In this paper we investigate how photoelectric and Compton basis functions, and synthesized monochromatic basis (SMB) functions behave in the presence of metal and its effect on estimation of effective atomic number and density. Our results indicate that SMB functions, along with edge-preserving total variation regularization, show promise for improved material estimation in the presence of metal. The results are demonstrated using both simulated data as well as data collected from a dualenergy medical CT scanner.

scholarly journals A novel low-dose dual-energy imaging method for a fast-rotating gantry-type CT scanner

2020 ◽  
pp. 1-1
Author(s):  
Sanghoon Cho ◽  
Seoyoung Lee ◽  
Jongha Lee ◽  
Donghyeon Lee ◽  
Hyoyi Kim ◽  
...  
Keyword(s):  
Low Dose ◽  
Dual Energy ◽  
Imaging Method ◽  
Ct Scanner ◽  
Dual Energy Imaging ◽  
Fast Rotating

scholarly journals A Method to Improve Electron Density Measurement of Cone-Beam CT Using Dual Energy Technique

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Kuo Men ◽  
Jian-Rong Dai ◽  
Ming-Hui Li ◽  
Xin-Yuan Chen ◽  
Ke Zhang ◽  
...  
Keyword(s):  
Electron Density ◽  
Cone Beam Ct ◽  
Density Measurement ◽  
Dual Energy ◽  
Cone Beam ◽  
Imaging Method ◽  
Basis Material ◽  
X Ray ◽  
Dual Energy Imaging ◽  
Set Up

Purpose. To develop a dual energy imaging method to improve the accuracy of electron density measurement with a cone-beam CT (CBCT) device.Materials and Methods. The imaging system is the XVI CBCT system on Elekta Synergy linac. Projection data were acquired with the high and low energy X-ray, respectively, to set up a basis material decomposition model. Virtual phantom simulation and phantoms experiments were carried out for quantitative evaluation of the method. Phantoms were also scanned twice with the high and low energy X-ray, respectively. The data were decomposed into projections of the two basis material coefficients according to the model set up earlier. The two sets of decomposed projections were used to reconstruct CBCT images of the basis material coefficients. Then, the images of electron densities were calculated with these CBCT images.Results. The difference between the calculated and theoretical values was within 2% and the correlation coefficient of them was about 1.0. The dual energy imaging method obtained more accurate electron density values and reduced the beam hardening artifacts obviously.Conclusion. A novel dual energy CBCT imaging method to calculate the electron densities was developed. It can acquire more accurate values and provide a platform potentially for dose calculation.

A zero dead-time, multihit, time and position sensitive detector based on micro-channel plates

2005 ◽  
Vol 76 (4) ◽  
pp. 043304 ◽  
Author(s):  
I. M. Ismail ◽  
M. Barat ◽  
J.-C. Brenot ◽  
J. A. Fayeton ◽  
V. Lepère ◽  
...  
Keyword(s):  
Dead Time ◽  
Position Sensitive Detector ◽  
Micro Channel ◽  
Sensitive Detector ◽  
Position Sensitive

A High-Speed Signal Processor Using a Digital Divider for Position Sensitive Proportional Counters

1980 ◽  
Vol 24 ◽  
pp. 173-176
Author(s):  
S. Kobashi ◽  
K. Mochiki ◽  
K. Hasegawa ◽  
A. Sekiguchi ◽  
H. Hashizume ◽  
...  
Keyword(s):  
High Speed ◽  
Dead Time ◽  
Present System ◽  
X Ray Diffraction ◽  
Analog To Digital ◽  
X Ray ◽  
System A ◽  
Proportional Counters ◽  
Position Sensitive ◽  
A Charge

Most position sensitive proportional counters (PSPCs) currently used in X-ray diffraction experiments have a dead time longer than 5 μs. Though such PSPCs are useful in measuring weak diffraction diagrams, a faster counter is needed to detect strong X-ray diagrams produced with synchrotron radiation sources. The long dead time of PSPCs using a charge division position read-out is due to the slow analog division circuit plus analog-to-digital converter employed in the present system. A fast processor can be built utilising two high-speed ADCs to digitize voltage signals from the detector, followed by a digital divider to compute position of detected photons. The present paper describes the design of such a processor and some preliminary testings of its performances.

Dual energy imaging with a dual-layer flat panel detector

2019 ◽  
Author(s):  
Minghui Lu ◽  
Adam Wang ◽  
Edward Shapiro ◽  
Amy Shiroma ◽  
Jin Zhang ◽  
...  
Keyword(s):  
Dual Energy ◽  
Flat Panel ◽  
Flat Panel Detector ◽  
Dual Energy Imaging
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