Assessment of 3D-TOF-MRA at 3.0 tesla in the characterization of the angioarchitecture of cerebral arteriovenous malformations: a preliminary study

2007 ◽  
Vol 48 (6) ◽  
pp. 678-686 ◽  
Author(s):  
J. O. Heidenreich ◽  
A. M. Schilling ◽  
F. Unterharnscheidt ◽  
R. Stendel ◽  
S. Hartlieb ◽  
...  
Keyword(s):  
Image Quality ◽  
Gold Standard ◽  
Signal To Noise Ratio ◽  
Brain Arteriovenous Malformation ◽  
3.0 Tesla ◽  
Detection Rates ◽  
Tof Mra ◽  
Preliminary Study

Background: The characterization of brain arteriovenous malformation (AVM) angioarchitecture remains rewarding in planning and predicting therapy. The increased signal-to-noise ratio at higher field strength has been found advantageous in vascular brain pathologies. Purpose: To evaluate whether 3.0T time-of-flight (TOF) magnetic resonance angiography (MRA) is superior to 1.5T TOF-MRA for the characterization of cerebral AVMs. Material and Methods: Fifteen patients with AVM underwent TOF-MRA at 3.0T and 1.5T and catheter angiography (DSA), which was used as the gold standard. Blinded readers scored image quality on a four-point scale, nidus size, and number of feeding arteries and draining veins. Results: Image quality of TOF-MRA at 3.0T was superior to 1.5T but still inferior to DSA. Evaluation of nidus size was equally good at 3.0T and 1.5T for all AVMs. In small AVMs, however, there was a tendency of size overestimation at 3.0T. MRA at 3.0T had increased detection rates for feeding arteries (+21%) and superficial (+13%) and deep draining veins (+33%) over 1.5T MRA. Conclusion: 3.0T TOF-MRA offers superior characterization of AVM angioarchitecture compared with 1.5T TOF-MRA. The image quality of MRA at both 3.0 and 1.5T is still far from equal to DSA, which remains the gold standard for characterization of AVM.

Image Quality Enhancing by Efficient Histogram Equalization

2014 ◽  
Vol 2 (2) ◽  
pp. 47-58
Author(s):  
Ismail Sh. Baqer
Keyword(s):  
Image Quality ◽  
Contrast Enhancement ◽  
Mean Squared Error ◽  
Signal To Noise Ratio ◽  
Histogram Equalization ◽  
Gray Level ◽  
Signal To Noise ◽  
Squared Error ◽  
Noise Ratio

A two Level Image Quality enhancement is proposed in this paper. In the first level, Dualistic Sub-Image Histogram Equalization DSIHE method decomposes the original image into two sub-images based on median of original images. The second level deals with spikes shaped noise that may appear in the image after processing. We presents three methods of image enhancement GHE, LHE and proposed DSIHE that improve the visual quality of images. A comparative calculations is being carried out on above mentioned techniques to examine objective and subjective image quality parameters e.g. Peak Signal-to-Noise Ratio PSNR values, entropy H and mean squared error MSE to measure the quality of gray scale enhanced images. For handling gray-level images, convenient Histogram Equalization methods e.g. GHE and LHE tend to change the mean brightness of an image to middle level of the gray-level range limiting their appropriateness for contrast enhancement in consumer electronics such as TV monitors. The DSIHE methods seem to overcome this disadvantage as they tend to preserve both, the brightness and contrast enhancement. Experimental results show that the proposed technique gives better results in terms of Discrete Entropy, Signal to Noise ratio and Mean Squared Error values than the Global and Local histogram-based equalization methods

Preliminary study of improved median filter using adaptively mask size in light microscopic image

Microscopy ◽  
2020 ◽  
Vol 69 (1) ◽  
pp. 31-36
Author(s):  
Ji-Youn Kim ◽  
Youngjin Lee
Keyword(s):  
Image Quality ◽  
Coefficient Of Variation ◽  
Signal To Noise Ratio ◽  
Median Filter ◽  
Microscopic Image ◽  
Signal To Noise ◽  
Mask Size ◽  
Preliminary Study ◽  
Noise Ratio ◽  
Image Details

Abstract This study aimed to develop and evaluate an improved median filter (IMF) with an adaptive mask size for light microscope (LM) images. We acquired images of the mouse first molar using a LM at 100× magnification. The images obtained using our proposed IMF were compared with those from a conventional median filter. Several parameters such as the contrast-to-noise ratio, coefficient of variation, no-reference assessments and peak signal-to-noise ratio were employed to evaluate the image quality quantitatively. The results demonstrated that the proposed IMF could effectively de-noise the LM images and preserve the image details, achieving a better performance than the conventional median filter.

The Influence of Alteration of kVp and mAs towards the Image Quality of Acrylic Using CBCT

2019 ◽  
Vol 829 ◽  
pp. 252-257
Author(s):  
Azhari ◽  
Yohanes Hutasoit ◽  
Freddy Haryanto
Keyword(s):  
Image Quality ◽  
Signal To Noise Ratio ◽  
Region Of Interest ◽  
Signal To Noise ◽  
Bite Block ◽  
Significant Difference ◽  
Noise Ratio ◽  
Post Hoc ◽  
Radiograph Image

CBCT is a modernized technology in producing radiograph image on dentistry. The image quality excellence is very important for clinicians to interpret the image, so the result of diagnosis produced becoming more accurate, appropriate, thus minimizing the working time. This research was aimed to assess the image quality using the blank acrylic phantom polymethylmethacrylate (PMMA) (C­5H8O2)n in the density of 1.185 g/cm3 for evaluating the homogeneity and uniformity of the image produced. Acrylic phantom was supported with a tripod and laid down on the chin rest of the CBCT device, then the phantom was fixed, and the edge of the phantom was touched by the bite block. Furthermore, the exposure of the X-ray was executed toward the acrylic phantom with various kVp and mAs, from 80 until 90, with the range of 5 kV and the variation of mA was 3, 5, and 7 mA respectively. The time exposure was kept constant for 25 seconds. The samples were taken from CBCT acrylic images, then as much as 5 ROIs (Region of Interest) was chosen to be analyzed. The ROIs determination was analyzed by using the ImageJ® software for recognizing the influence of kVp and mAs towards the image uniformity, noise and SNR. The lowest kVp and mAs had the result of uniformity value, homogeneity and signal to noise ratio of 11.22; 40.35; and 5.96 respectively. Meanwhile, the highest kVp and mAs had uniformity value, homogeneity and signal to noise ratio of 16.96; 26.20; and 5.95 respectively. There were significant differences between the image uniformity and homogeneity on the lowest kVp and mAs compared to the highest kVp and mAs, as analyzed with the ANOVA statistics analysis continued with the t-student post-hoc test with α = 0.05. However, there was no significant difference in SNR as analyzed with the ANOVA statistic analysis. The usage of the higher kVp and mAs caused the improvement of the image homogeneity and uniformity compared to the lower kVp and mAs.

Quality of Computed Tomography Pulmonary Embolism and Aortic Phase Images Acquired with Power Injection via an Arm Port

2017 ◽  
Vol 22 (2) ◽  
pp. 88-92
Author(s):  
Ryan Verity ◽  
David Leswick ◽  
Brent Burbridge ◽  
Rhonda Bryce ◽  
Hyun Lim
Keyword(s):  
Computed Tomography ◽  
Pulmonary Embolism ◽  
Image Quality ◽  
Thin Section ◽  
Signal To Noise Ratio ◽  
Contrast Injection ◽  
Signal To Noise ◽  
Streak Artifact ◽  
Noise Ratio

Abstract Background: The safety of power-injectable implanted arm ports is well established, but there is insufficient data to conclude that image quality of computed tomography resulting from contrast introduced via the port is of equal quality to images derived from contrast introduced via traditional peripheral access. The objective of this study was to determine whether the image quality of computed tomography pulmonary embolism and computed tomography aorta studies would differ when injecting contrast via an implanted arm port vs a peripheral intravenous site. We hypothesized that injecting via an implanted arm port would produce better-quality images, the result of more appropriate timing and less streak artifact. Methods: Scans from a provincial database search for patients who underwent a computed tomography pulmonary embolism or aorta study with contrast injection via the implanted arm port and thin section images available, were reviewed (pulmonary embolism studies n = 3, aorta studies n = 3). Only a limited number of patients were available for review because there are currently few patients with these ports in place and we limited evaluation to thin section images. Comparison was made with 6 control patients who did not have a port and had received a peripheral arm intravenous contrast injection for these study types. Objective measurements included signal-to-noise ratio and contrast-to-noise ratio of the pulmonary arteries (4 sites) and aorta (2 sites) as appropriate for scan type. Subjective analysis of image quality was performed by 2 radiologists. Results: Although sample size was limited, the implanted arm port group had similar or higher mean signal-to-noise ratio and contrast-to-noise ratio values at all sites. Subjective assessments showed the implanted arm port group to have similar or better opacification and diagnostic confidence; similar or less streak artifact was also observed at each of the sites. Conclusions: These exploratory results suggest that studies with implanted arm port injection can generate high-quality images on both objective and subjective assessment, similar to, or possibly better than, images generated from usual peripheral intravenous access for contrast injection.

scholarly journals Electrochemical study and characterization of tin coatings with and without glucose-based additive

2021 ◽  
Vol 11 (3) ◽  
pp. 264
Author(s):  
Sghir Cherrouf ◽  
Yassine Salhi ◽  
Amina El Echhab ◽  
Hassan El Grini ◽  
Jihane Tellal ◽  
...  
Keyword(s):  
Steel Substrate ◽  
X Ray Diffraction ◽  
Tin Coating ◽  
Good Surface ◽  
Tin Coatings ◽  
Apparent Decrease ◽  
Preliminary Study ◽  
Ordinary Steel

<p>The tin coating was elaborated electrolytically on an ordinary steel substrate in SnSO<sub>4</sub> based electrolyte in acid medium with additive (bis-glycobenzimidazolone) at ambient temperature. The pH is maintained at 1.2±0.2 Bis-glycobenzimidazolone influence on the electrochemical properties of the tin coating was investigated using stationary polarization, chronopotentiometry, and cyclic voltammetry techniques. These studies show an apparent decrease in cathodic peak current and a drop in potential. The deposition rate also decreases as the concentration of the additive increases.  SEM (Scanning Electron Microscopy) observation and XRD (X-ray Diffraction) analysis showed that the coating consists of good surface quality of the deposit elaborated by the addition of an optimal concentration of bis-glycobenzimidazolone (10<sup>-3</sup>M) in the electrolyte, which constitutes the continuation of a preliminary study.<strong></strong></p>

scholarly journals Influence of orthodontic brackets and permanent retainers on the diagnostic image quality of MRI scans: A preliminary study

2021 ◽  
Vol 58 (4) ◽  
pp. 0-0
Author(s):  
Praveen Kumar Neela ◽  
Venkat Kishan ◽  
Mohammed Wahajuddin Syed ◽  
Pavan Kumar Mamillapalli ◽  
Vasu Murthy Sesham ◽  
...  
Keyword(s):  
Image Quality ◽  
Orthodontic Brackets ◽  
Diagnostic Image Quality ◽  
Diagnostic Image ◽  
Mri Scans ◽  
Preliminary Study

An Approach to Measuring the Point Spread Function of the Confocal Raman Microscope

2020 ◽  
Vol 74 (10) ◽  
pp. 1230-1237
Author(s):  
Xiang Ding ◽  
Yanzhe Fu ◽  
Jiyan Zhang ◽  
Yao Hu ◽  
Shihang Fu
Keyword(s):  
Image Quality ◽  
Size Effect ◽  
Point Spread Function ◽  
Performance Indicator ◽  
Signal To Noise Ratio ◽  
Polystyrene Microspheres ◽  
Point Spread ◽  
Spread Function ◽  
Confocal Raman

The confocal Raman microscope (CRM) is a powerful tool in analytical science. Image quality is the most important performance indicator of CRM systems. The point spread function (PSF) is one of the most useful tools to evaluate the image quality of microscopic systems. A method based on a point-like object is proposed to measure the PSF of CRM, and the size effect of spherical objects is discussed. A series of phantoms are fabricated by embedding different sizes of polystyrene microspheres into polydimethylsiloxane matrix. The diameters of microspheres are from 0.2 µm to 5 µm. The phantoms are tested by measuring the PSF of a commercial CRM whose nominal lateral resolution is about 1 µm. Results of the PSF are obtained and the accuracy of resolution is used to evaluate the size effect of the microspheres. Experimental results are well consistent with theoretical analysis. The error of the PSF can be decreased by reducing the diameter of the microsphere but meanwhile the signal-to-noise ratio (S/N) will be lowered as well. The proper diameter of microspheres is proposed in consideration of the trade-off between the S/N and the measurement error of the PSF. Results indicate that the method provides a useful approach to measurement of the PSF and the resolution of the CRM.

Image quality of digital chest radiography: evaluation of subtle interstitial lung abnormalities (preliminary study)

1994 ◽  
Vol 43 (1-2) ◽  
pp. 107-114 ◽  
Author(s):  
Junpei Ikezoe ◽  
Shoji Kido ◽  
Noriyuki Takeuchi ◽  
Hiroshi Kondoh ◽  
Jun Arisawa ◽  
...  
Keyword(s):  
Image Quality ◽  
Chest Radiography ◽  
Lung Abnormalities ◽  
Digital Chest ◽  
Preliminary Study
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