scholarly journals Comparison of image quality of an abdominal acquisition mode of angiography systems from four major manufacturers

2018 ◽  
Vol 5 (2) ◽  
pp. 6
Author(s):  
Lucie Sukupova ◽  
Jan Rydlo ◽  
Ondrej Hlavacek ◽  
Daniel Vedlich ◽  
Jan H. Peregrin
Keyword(s):  
Image Quality ◽  
Line Pair ◽  
Obese Patients ◽  
Clinical Images ◽  
Contrast Resolution ◽  
Low Contrast ◽  
System A ◽  
Acquisition Mode ◽  
Air Kerma Rate

Objective: The aim of this study was to compare image quality of different abdominal acquisition modes under conditions simulating obese patients whose images suffer more from noise and scatter radiation. Images were acquired in clinically used acquisition modes on the static and dynamic phantom for four angiography systems.Methods: A LEGO cart with 34 cm of PMMA and Pro-RTG Fluo18 phantom were used to simulate obese patients. The low-contrast resolution was assessed subjectively by two readers and objectively using signal-difference-to-noise ratio (SDNR) and using SDNR to air kerma rate. The line-pair resolution was assessed using the transmitted contrast value for line-pair groups.Results: Systems use different exposure parameters and dose but they differ in postprocessing too. Qualitative and quantitative assessments of noise produced similar results, images produced by systems A and C were noisier than by systems B and D. Highest SDNR was provided by System B, whilst System A produced the lowest values, which were almost the same for objects with different contrast. The image quality was affected mainly by frame lengths and postprocessing, but also by the dose. The images of the static phantom were better compared to the images of the dynamic phantom, which was an expected result.Conclusions: It was possible to identify image quality differences and to characterize features of postprocessing from measurements on standardized objects. A potential for optimization on some systems was identified, although further work, including assessment of clinical images, would be needed as part of the optimization process.

scholarly journals Modeling and image quality enhancement for dynamic compressive imaging system

2021 ◽  
Vol 15 ◽  
pp. 174830262110080
Author(s):  
Changjun Zha* ◽  
Qian Zhang* ◽  
Huimin Duan
Keyword(s):  
Image Quality ◽  
Imaging System ◽  
Quality Enhancement ◽  
Target Image ◽  
Compressive Imaging ◽  
Image Quality Enhancement ◽  
System A ◽  
Single Column ◽  
The Impact

Traditional single-pixel imaging systems are aimed mainly at relatively static or slowly changing targets. When there is relative motion between the imaging system and the target, sizable deviations between the measurement values and the real values can occur and result in poor image quality of the reconstructed target. To solve this problem, a novel dynamic compressive imaging system is proposed. In this system, a single-column digital micro-mirror device is used to modulate the target image, and the compressive measurement values are obtained for each column of the image. Based on analysis of the measurement values, a new recovery model of dynamic compressive imaging is given. Differing from traditional reconstruction results, the measurement values of any column of vectors in the target image can be used to reconstruct the vectors of two adjacent columns at the same time. Contingent upon characteristics of the results, a method of image quality enhancement based on an overlapping average algorithm is proposed. Simulation experiments and analysis show that the proposed dynamic compressive imaging can effectively reconstruct the target image; and that when the moving speed of the system changes within a certain range, the system reconstructs a better original image. The system overcomes the impact of dynamically changing speeds, and affords significantly better performance than traditional compressive imaging.

How Good is Too Good? A Subjective Study on Over Enhancement of Images

2021 ◽  
Vol 2021 (29) ◽  
pp. 83-88
Author(s):  
Sahar Azimian ◽  
Farah Torkamani Azar ◽  
Seyed Ali Amirshahi
Keyword(s):  
Image Quality ◽  
High Contrast ◽  
Current Image ◽  
Low Contrast ◽  
Image Dataset ◽  
Long Time ◽  
Reference Images ◽  
Subjective Study ◽  
Contrast Image

For a long time different studies have focused on introducing new image enhancement techniques. While these techniques show a good performance and are able to increase the quality of images, little attention has been paid to how and when overenhancement occurs in the image. This could possibly be linked to the fact that current image quality metrics are not able to accurately evaluate the quality of enhanced images. In this study we introduce the Subjective Enhanced Image Dataset (SEID) in which 15 observers are asked to enhance the quality of 30 reference images which are shown to them once at a low and another time at a high contrast. Observers were instructed to enhance the quality of the images to the point that any more enhancement will result in a drop in the image quality. Results show that there is an agreement between observers on when over-enhancement occurs and this point is closely similar no matter if the high contrast or the low contrast image is enhanced.

scholarly journals Radiation dose and image quality of high-pitch emergency abdominal CT in obese patients using third-generation dual-source CT (DSCT)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Robert Forbrig ◽  
Michael Ingrisch ◽  
Robert Stahl ◽  
Katharina Stella Winter ◽  
Maximilian Reiser ◽  
...  
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Third Generation ◽  
Obese Patients ◽  
Dual Source Ct ◽  
High Pitch ◽  
Subjective Image Quality ◽  
Dual Source ◽  
Group A

Abstract In this third-generation dual-source CT (DSCT) study, we retrospectively investigated radiation dose and image quality of portal-venous high-pitch emergency CT in 60 patients (28 female, mean age 56 years) with a body mass index (BMI) ≥ 30 kg/m2. Patients were dichotomized in groups A (median BMI 31.5 kg/m2; n = 33) and B (36.8 kg/m2; n = 27). Volumetric CT dose index (CTDIvol), size-specific dose estimate (SSDE), dose length product (DLP) and effective dose (ED) were assessed. Contrast-to-noise ratio (CNR) and dose-independent figure-of-merit (FOM) CNR were calculated. Subjective image quality was assessed using a five-point scale. Mean values of CTDIvol, SSDE as well as normalized DLP and ED were 7.6 ± 1.8 mGy, 8.0 ± 1.8 mGy, 304 ± 74 mGy * cm and 5.2 ± 1.3 mSv for group A, and 12.6 ± 3.7 mGy, 11.0 ± 2.6 mGy, 521 ± 157 mGy * cm and 8.9 ± 2.7 mSv for group B (p < 0.001). CNR of the liver and spleen as well as each calculated FOM CNR were significantly higher in group A (p < 0.001). Subjective image quality was good in both groups. In conclusion, third-generation abdominal high-pitch emergency DSCT yields good image quality in obese patients. Radiation dose increases in patients with a BMI > 36.8 kg/m2.

scholarly journals Numerical evaluation of image parameters of ETR-1

2016 ◽  
Vol 2 (1) ◽  
pp. 489-491
Author(s):  
Shamim Ahmed ◽  
Marian Krüger ◽  
Christian Willomitzer ◽  
Golam A. Zakaria
Keyword(s):  
Image Quality ◽  
Treatment Planning ◽  
Numerical Evaluation ◽  
Numerical Estimation ◽  
Low Contrast ◽  
Precise Result ◽  
Test Tool ◽  
Naked Eye ◽  
Pre Treatment

AbstractIn this work, we developed a method to handle the image quality test-tool precisely. This test-tool is important to evaluate the quality of the medical images for pre-treatment planning phase. But the achieved images are estimated by naked eyes, which does not provide the precise result. Our main goal is to get the desired image parameters numerically. This numerical estimation overcomes the limitation of naked eye observation. Hence, it enhances the pre-treatment planning. The ETR-1 test-tool is considered here. The contrast, the low contrast details and line-pairs (lp/mm) were estimated.

Diagnostic confidence and image quality of CT pulmonary angiography at 100 kVp in overweight and obese patients

2015 ◽  
Vol 70 (1) ◽  
pp. 54-61 ◽  
Author(s):  
B. Megyeri ◽  
A. Christe ◽  
S.T. Schindera ◽  
E. Horkay ◽  
J. Sikula ◽  
...  
Keyword(s):  
Image Quality ◽  
Pulmonary Angiography ◽  
Obese Patients ◽  
Ct Pulmonary Angiography ◽  
Diagnostic Confidence

Improvements to image quality using hybrid and model-based iterative reconstructions: a phantom study

2016 ◽  
Vol 58 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Marie-Louise Aurumskjöld ◽  
Kristina Ydström ◽  
Anders Tingberg ◽  
Marcus Söderberg
Keyword(s):  
Image Quality ◽  
Radiation Dose ◽  
Iterative Reconstruction ◽  
Power Spectra ◽  
Reconstruction Method ◽  
Noise Power ◽  
Contrast Resolution ◽  
Low Contrast ◽  
Model Based ◽  
Reconstruction Methods

Background The number of computed tomography (CT) examinations is increasing and leading to an increase in total patient exposure. It is therefore important to optimize CT scan imaging conditions in order to reduce the radiation dose. The introduction of iterative reconstruction methods has enabled an improvement in image quality and a reduction in radiation dose. Purpose To investigate how image quality depends on reconstruction method and to discuss patient dose reduction resulting from the use of hybrid and model-based iterative reconstruction. Material and Methods An image quality phantom (Catphan® 600) and an anthropomorphic torso phantom were examined on a Philips Brilliance iCT. The image quality was evaluated in terms of CT numbers, noise, noise power spectra (NPS), contrast-to-noise ratio (CNR), low-contrast resolution, and spatial resolution for different scan parameters and dose levels. The images were reconstructed using filtered back projection (FBP) and different settings of hybrid (iDose4) and model-based (IMR) iterative reconstruction methods. Results iDose4 decreased the noise by 15–45% compared with FBP depending on the level of iDose4. The IMR reduced the noise even further, by 60–75% compared to FBP. The results are independent of dose. The NPS showed changes in the noise distribution for different reconstruction methods. The low-contrast resolution and CNR were improved with iDose4, and the improvement was even greater with IMR. Conclusion There is great potential to reduce noise and thereby improve image quality by using hybrid or, in particular, model-based iterative reconstruction methods, or to lower radiation dose and maintain image quality.

Sign in / Sign up

Export Citation Format

Share Document