&lt;title&gt;Performance of image intensifiers in radiographic systems&lt;/title&gt;

Baker, Stuart A.; King, N.S.P.; Lewis, Wilfred; Lutz, S. S.; Морган, Д.; Schaefer, Tim; Wilke, M. D.

doi:10.1117/12.378879

Cited by 3 publications

(4 citation statements)

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“…The MTF, NPS and DQE of the X-ray imaging module were determined using a standard computation method described by previous research groups [2][3][4][5][6][7][8][9][10][11][12][13][14][20][21] . The main steps to calculate the MTF, NPS and DQE are shown by the schematics (see Fig.7, Fig.10 and Fig.12 respectively).…”

Section: Calculation Of Mtf Nps and Dqe For X-ray Imaging Modulementioning

confidence: 99%

“…It measures the ability of the imaging detector to characterize a radiation pattern whose intensity varies sinusoidally in a one dimensional plane for a corresponding distance. MTF can be calculated by the slit method, square wave method, sine wave method, sine wave response method, and the edge method [2][3][4][5][6][7][8][9][10][11][12][13][14] . Similarly, the NPS characterizes the image noise and the shape of the spectrum determines the frequency space where the noise power is concentrated.…”

Section: Introductionmentioning

confidence: 99%

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Performance evaluation of a combined neutron and x-ray digital imaging system

et al. 2013

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A neutron and X-ray combined computed tomography system (NXCT) has been developed 1 at the Missouri University of Science & Technology. It is believed that it will provide a superior method for non-destructive testing and evaluation. The system is housed within the Missouri University of Science & Technology Reactor (MSTR) and is the first such imaging platform and synthesis method to be developed. The system utilizes neutrons obtained directly from the reactor core and X-rays an X-ray generator. Characterization of the newly developed digital imaging system is imperative to the performance evaluation, as well as for describing the associated parameters. The preliminary evaluation of the NXCT system was performed in terms of image uniformity, linearity and spatial resolution. Additionally, the correlation between the applied beam intensity, the resulting image quality, and the system sensitivity was investigated. The combined neutron/X-ray digital imaging system was evaluated in terms of performance parameters and results are detailed. The MTF of the X-ray imaging module was calculated using the Edge method. The spatial frequency at 10% of the MTF was found to be 8 lp/mm, which is in agreement with the value of 8.5 lp/mm determined from the square wave response method. The highest detective quantum efficiency of the X-ray imaging module was found to be 0.13. Furthermore, the NPS spectrum for the neutron imaging module was also evaluated in a similar way as the X-ray imaging module. In order to improve the image quality of the neutron imaging module, a pin-hole mask phantom was used to correct the geometrical non-linearity of the delay line anode readout. The non-linearity correction of the delay line anode readout has been shown through the corrected images of perforated cadmium strip and electroformed phantom.

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Section: Calculation Of Mtf Nps and Dqe For X-ray Imaging Modulementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Performance evaluation of a combined neutron and x-ray digital imaging system

et al. 2013

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“…Photon sensitivity (counts per Joule/cm 2 ) is calibrated radiometrically. A measure of detective quantum efficiency (DQE) 10 of the system can be calculated based on observed SNR and modeled x-ray photons incident on the scintillator per resolution element.…”

Section: Methodsmentioning

confidence: 99%

Scintillator efficiency study with MeV x-rays

et al. 2014

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We have investigated scintillator efficiency for MeV radiographic imaging. This paper discusses the modeled detection efficiency and measured brightness of a number of scintillator materials. An optical imaging camera records images of scintillator emission excited by a pulsed x-ray machine. The efficiency of various thicknesses of monolithic LYSO:Ce (cerium-doped lutetium yttrium orthosilicate) are being studied to understand brightness and resolution trade-offs compared with a range of micro-columnar CsI:Tl (thallium-doped cesium iodide) scintillator screens. The micro-columnar scintillator structure apparently provides an optical gain mechanism that results in brighter signals from thinner samples. The trade-offs for brightness versus resolution in monolithic scintillators is straightforward. For higher-energy x-rays, thicker materials generally produce brighter signal due to x-ray absorption and the optical emission properties of the material. However, as scintillator thickness is increased, detector blur begins to dominate imaging system resolution due to the volume image generated in the scintillator thickness and the depth of field of the imaging system. We employ a telecentric optical relay lens to image the scintillator onto a recording CCD camera. The telecentric lens helps provide sharp focus through thicker-volume emitting scintillators. Stray light from scintillator emission can also affect the image scene contrast. We have applied an optical light scatter model to the imaging system to minimize scatter sources and maximize scene contrasts.

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“…The modulation transfer function plot shown in Figure 5 is calculated from an edge image in the object plane. 5,7,8 The MTF plot, the sinusoidal frequency response, is a convenient way to view the resolution of a camera system. Notable points from the plot are the 50% modulation frequency, identified as the cutoff frequency, f c , and the limiting resolution spatial frequency, indicated as the modulation approaches 5%, or the maximum detectable resolution.…”

Section: Camera System Resolutionmentioning

confidence: 99%

Development and performance of Bechtel Nevada's nine-frame camera system

2002

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Bechtel Nevada, Los Alamos Operations, has developed a high-speed, nine-frame camera system that records a sequence from a changing or dynamic scene. The system incorporates an electrostatic image tube with custom gating and deflection electrodes. The framing tube is shuttered with high-speed gating electronics, yielding frame rates of up to 5 MHz. Dynamic scenes are lens-coupled to the camera, which contains a single photocathode gated on and off to control each exposure time. Deflection plates and drive electronics move the frames to different locations on the framing tube output. A single charge-coupled device (CCD) camera then records the phosphor image of all nine frames. This paper discusses setup techniques to optimize system performance. It examines two alternate philosophies for system configuration and respective performance results. We also present performance metrics for system evaluation, experimental results, and applications to four-frame cameras.

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<title>Performance of image intensifiers in radiographic systems</title>

Cited by 3 publications

References 1 publication

Performance evaluation of a combined neutron and x-ray digital imaging system

Performance evaluation of a combined neutron and x-ray digital imaging system

Scintillator efficiency study with MeV x-rays

Development and performance of Bechtel Nevada's nine-frame camera system

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