scholarly journals Simultaneous Dual-Color Fluorescence Microscope: A Characterization Study

2013 ◽  
Vol 36 (5-6) ◽  
pp. 163-172
Author(s):  
Zheng Li ◽  
Xiaodong Chen ◽  
Liqiang Ren ◽  
Jie Song ◽  
Yuhua Li ◽  
...  
Keyword(s):  
High Resolution ◽  
Transfer Function ◽  
Spatial Resolution ◽  
Imaging System ◽  
Fluorescence Microscope ◽  
Chromosomal Analysis ◽  
Dual Band ◽  
Geometric Distortion ◽  
Dual Color ◽  
Characterization Study

Background: High spatial resolution and geometric accuracy is crucial for chromosomal analysis of clinical cytogenetic applications. High resolution and rapid simultaneous acquisition of multiple fluorescent wavelengths can be achieved by utilizing concurrent imaging with multiple detectors. However, such class of microscopic systems functions differently from traditional fluorescence microscopes.Objective: To develop a practical characterization framework to assess and optimize the performance of a high resolution and dual-color fluorescence microscope designed for clinical chromosomal analysis.Methods: A dual-band microscopic imaging system utilizes a dichroic mirror, two sets of specially selected optical filters, and two detectors to simultaneously acquire two fluorescent wavelengths. The system’s geometric distortion, linearity, the modulation transfer function, and the dual detectors’ alignment were characterized.Results: Experiment results show that the geometric distortion at lens periphery is less than 1%. Both fluorescent channels show linear signal responses, but there exists discrepancy between the two due to the detectors’ non-uniform response ratio to different wavelengths. In terms of the spatial resolution, the two contrast transfer function curves trend agreeably with the spatial frequency. The alignment measurement allows quantitatively assessing the cameras' alignment. A result image of adjusted alignment is demonstrated to show the reduced discrepancy by using the alignment measurement method.Conclusions: In this paper, we present a system characterization study and its methods for a specially designed imaging system for clinical cytogenetic applications. The presented characterization methods are not only unique to this dual-color imaging system but also applicable to evaluation and optimization of other similar multi-color microscopic image systems for improving their clinical utilities for future cytogenetic applications.

Modular 64×64 CdZnTe Arrays With Multiplexer Readout for High-Resolution Nuclear Medicine Imaging

1997 ◽  
Vol 487 ◽  
Author(s):  
J. M. Woolfenden ◽  
H. B. Barber ◽  
H. H. Barrett ◽  
E. L. Dereniak ◽  
J. D. Eskin ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
High Resolution ◽  
Spatial Resolution ◽  
Personal Computer ◽  
Imaging System ◽  
Radiation Detectors ◽  
Readout Circuit ◽  
Nuclear Medicine Imaging ◽  
Pixel Pitch

AbstractWe are developing modular arrays of CdZnTe radiation detectors for high-resolution nuclear medicine imaging. Each detector is delineated into a 64×64 array of pixels; the pixel pitch is 380 jim. Each pixel is connected to a corresponding pad on a multiplexer readout circuit. The imaging system is controlled by a personal computer. We obtained images of standard nuclear medicine phantoms in which the spatial resolution of approximately 1.5 mm was limited by the collimator that was used. Significant improvements in spatial resolution should be possible with different collimator designs. These results are promising for high-resolution nuclear medicine imaging.

scholarly journals Wide Swath and High Resolution Airborne HyperSpectral Imaging System and Flight Validation

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1667 ◽  
Author(s):  
Dong Zhang ◽  
Liyin Yuan ◽  
Shengwei Wang ◽  
Hongxuan Yu ◽  
Changxing Zhang ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Spectral Resolution ◽  
High Efficiency ◽  
High Spatial Resolution ◽  
Imaging System ◽  
High Sensitivity ◽  
Field Of View ◽  
High Spectral Resolution ◽  
Wide Swath

Wide Swath and High Resolution Airborne Pushbroom Hyperspectral Imager (WiSHiRaPHI) is the new-generation airborne hyperspectral imager instrument of China, aimed at acquiring accurate spectral curve of target on the ground with both high spatial resolution and high spectral resolution. The spectral sampling interval of WiSHiRaPHI is 2.4 nm and the spectral resolution is 3.5 nm (FWHM), integrating 256 channels coving from 400 nm to 1000 nm. The instrument has a 40-degree field of view (FOV), 0.125 mrad instantaneous field of view (IFOV) and can work in high spectral resolution mode, high spatial resolution mode and high sensitivity mode for different applications, which can adapt to the Velocity to Height Ratio (VHR) lower than 0.04. The integration has been finished, and several airborne flight validation experiments have been conducted. The results showed the system’s excellent performance and high efficiency.

scholarly journals Phase-Controlled Planar Metalenses for High-Resolution Terahertz Focusing

Photonics ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 143
Author(s):  
Xin Yu ◽  
Yun Shen ◽  
Guohong Dai ◽  
Liner Zou ◽  
Tailin Zhang ◽  
...  
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Imaging System ◽  
Incident Light ◽  
Near Field ◽  
Numerical Aperture ◽  
Full Width ◽  
Half Maximum ◽  
Near Field Imaging ◽  
Field Imaging

We experimentally demonstrate that high-resolution terahertz focusing can be realized in planar metalenses, which consist of arrays of different V-shaped antenna units on a silicon substrate. Numerical results show that a larger numerical aperture of metalenses can provide smaller full width at half maximum of field distribution, leading to higher spatial resolution. The measurement of fabricated metalenses samples was performed by a terahertz near-field imaging system, and experimental results agree well with the numerical prediction. Especially for 1.1 THz incident light, when the numerical aperture increases from 0.79 to 0.95, the full width at half maximum correspondingly decreases from 343 μm to 206 μm, offering an improvement of spatial resolution.

Modular 64×64 CdZnTe Arrays With Multiplexer Readout for High-Resolution Nuclear Medicine Imaging

1997 ◽  
Vol 484 ◽  
Author(s):  
J. M. Woolfenden ◽  
H. B. Barber ◽  
H. H. Barrett ◽  
E. L. Dereniak ◽  
J. D. Eskin ◽  
...  
Keyword(s):  
Nuclear Medicine ◽  
High Resolution ◽  
Spatial Resolution ◽  
Personal Computer ◽  
Imaging System ◽  
Radiation Detectors ◽  
Readout Circuit ◽  
Nuclear Medicine Imaging ◽  
Pixel Pitch

AbstractWe are developing modular arrays of CdZnTe radiation detectors for high-resolution nuclear medicine imaging. Each detector is delineated into a 64×64 array of pixels; the pixel pitch is 380 ptm. Each pixel is connected to a corresponding pad on a multiplexer readout circuit. The imaging system is controlled by a personal computer. We obtained images of standard nuclear medicine phantoms in which the spatial resolution of approximately 1.5 mm was limited by the collimator that was used. Significant improvements in spatial resolution should be possible with different collimator designs. These results are promising for high-resolution nuclear medicine imaging.

scholarly journals X-ray fan beam coded aperture transmission and diffraction imaging for fast material analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Stefan Stryker ◽  
Joel A. Greenberg ◽  
Shannon J. McCall ◽  
Anuj J. Kapadia
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Imaging System ◽  
Coded Aperture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Imaging ◽  
Diffraction Imaging ◽  
Non Destructive ◽  
Ray Methods

AbstractX-ray transmission imaging has been used in a variety of applications for high-resolution measurements based on shape and density. Similarly, X-ray diffraction (XRD) imaging has been used widely for molecular structure-based identification of materials. Combining these X-ray methods has the potential to provide high-resolution material identification, exceeding the capabilities of either modality alone. However, XRD imaging methods have been limited in application by their long measurement times and poor spatial resolution, which has generally precluded combined, rapid measurements of X-ray transmission and diffraction. In this work, we present a novel X-ray fan beam coded aperture transmission and diffraction imaging system, developed using commercially available components, for rapid and accurate non-destructive imaging of industrial and biomedical specimens. The imaging system uses a 160 kV Bremsstrahlung X-ray source while achieving a spatial resolution of ≈ 1 × 1 mm2 and a spectral accuracy of > 95% with only 15 s exposures per 150 mm fan beam slice. Applications of this technology are reported in geological imaging, pharmaceutical inspection, and medical diagnosis. The performance of the imaging system indicates improved material differentiation relative to transmission imaging alone at scan times suitable for a variety of industrial and biomedical applications.

scholarly journals CORRECTING SPACECRAFT JITTER IN HIRISE IMAGES

2017 ◽  
Vol XLII-3/W1 ◽  
pp. 141-148
Author(s):  
S. S. Sutton ◽  
A. K. Boyd ◽  
R. L. Kirk ◽  
D. Cook ◽  
J. W. Backer ◽  
...  
Keyword(s):  
High Resolution ◽  
Imaging System ◽  
Image Correlation ◽  
Stereo Image ◽  
Geometric Distortion ◽  
Image Correction ◽  
Geometric Distortions ◽  
Mechanical Oscillations ◽  
Measuring Surface ◽  
Imaging Science

Mechanical oscillations or vibrations on spacecraft, also called pointing jitter, cause geometric distortions and/or smear in high resolution digital images acquired from orbit. Geometric distortion is especially a problem with pushbroom type sensors, such as the High Resolution Imaging Science Experiment (HiRISE) instrument on board the Mars Reconnaissance Orbiter (MRO). Geometric distortions occur at a range of frequencies that may not be obvious in the image products, but can cause problems with stereo image correlation in the production of digital elevation models, and in measuring surface changes over time in orthorectified images. The HiRISE focal plane comprises a staggered array of fourteen charge-coupled devices (CCDs) with pixel IFOV of 1 microradian. The high spatial resolution of HiRISE makes it both sensitive to, and an excellent recorder of jitter. We present an algorithm using Fourier analysis to resolve the jitter function for a HiRISE image that is then used to update instrument pointing information to remove geometric distortions from the image. Implementation of the jitter analysis and image correction is performed on selected HiRISE images. Resulting corrected images and updated pointing information are made available to the public. Results show marked reduction of geometric distortions. This work has applications to similar cameras operating now, and to the design of future instruments (such as the Europa Imaging System).

scholarly journals High-resolution and Monte Carlo additions to the SASKTRAN radiative transfer model

2015 ◽  
Vol 8 (6) ◽  
pp. 2609-2623 ◽  
Author(s):  
D. J. Zawada ◽  
S. R. Dueck ◽  
L. A. Rieger ◽  
A. E. Bourassa ◽  
N. D. Lloyd ◽  
...  
Keyword(s):  
Monte Carlo ◽  
High Resolution ◽  
Radiative Transfer ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Imaging System ◽  
Monte Carlo Model ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Systematic Bias

Abstract. The Optical Spectrograph and InfraRed Imaging System (OSIRIS) instrument on board the Odin spacecraft has been measuring limb-scattered radiance since 2001. The vertical radiance profiles measured as the instrument nods are inverted, with the aid of the SASKTRAN radiative transfer model, to obtain vertical profiles of trace atmospheric constituents. Here we describe two newly developed modes of the SASKTRAN radiative transfer model: a high-spatial-resolution mode and a Monte Carlo mode. The high-spatial-resolution mode is a successive-orders model capable of modelling the multiply scattered radiance when the atmosphere is not spherically symmetric; the Monte Carlo mode is intended for use as a highly accurate reference model. It is shown that the two models agree in a wide variety of solar conditions to within 0.2 %. As an example case for both models, Odin–OSIRIS scans were simulated with the Monte Carlo model and retrieved using the high-resolution model. A systematic bias of up to 4 % in retrieved ozone number density between scans where the instrument is scanning up or scanning down was identified. The bias is largest when the sun is near the horizon and the solar scattering angle is far from 90°. It was found that calculating the multiply scattered diffuse field at five discrete solar zenith angles is sufficient to eliminate the bias for typical Odin–OSIRIS geometries.

scholarly journals Modulation transfer function evaluation of cone beam computed and microcomputed tomography by using slanted edge phantom

2019 ◽  
Author(s):  
Szabó TAMÁS BENCE
Keyword(s):  
Transfer Function ◽  
Spatial Resolution ◽  
Modulation Transfer Function ◽  
Imaging System ◽  
Ct Images ◽  
Function Evaluation ◽  
Strong Positive Correlation ◽  
Micro Ct ◽  
Modulation Transfer ◽  
Voxel Size

Modulation transfer function (MTF) is a well known and widely accepted method for evaluating the spatial resolution of a digital radiographic imaging system. In the present study our aim was to evaluate the MTF obtained from CBCT and micro-CT images. A cylinder shaped phantom designed for slanted-edge method was scanned by a CBCT device at a 100 µm isometric voxel size and by a micro-CT device at a 20 µm isometric voxel size, simultaneously. The MTF curves were calculated and the mean spatial resolutions at 10% MTF were 3.33 + 0.29 lp/mm in the case of CBCT images and 13.35 + 2.47 lp/mm in the case of micro-CT images. The values showed a strong positive correlation regarding the CBCT and the micro-CT spatial resolution values, respectively. Our results suggests that CBCT imaging devices with a voxel size of 100 µm or below might aid the validation of fine anatomical structures and allowing the opportunity for reliable micromorphometric examinations

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