scholarly journals A projection image database to investigate factors affecting image quality in weight-based dosing: application to pediatric renal SPECT

2018 ◽  
Vol 63 (14) ◽  
pp. 145004 ◽  
Author(s):  
Ye Li ◽  
Shannon O’Reilly ◽  
Donika Plyku ◽  
S Ted Treves ◽  
Yong Du ◽  
...  
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.


1999 ◽  
Vol 29 (2) ◽  
pp. 81-84 ◽  
Author(s):  
G Kaeppler ◽  
D Axmann-Krcmar ◽  
I Reuter ◽  
J Meyle ◽  
G Gómez-Román

Get Through ◽  
2020 ◽  
pp. 39-55
Author(s):  
Damian Tolan ◽  
Rachel Hyland ◽  
Christopher Taylor ◽  
Arnold Cowen

2021 ◽  
Vol 2021 (29) ◽  
pp. 258-263
Author(s):  
Marius Pedersen ◽  
Seyed Ali Amirshahi

Over the years, a high number of different objective image quality metrics have been proposed. While some image quality metrics show a high correlation with subjective scores provided in different datasets, there still exists room for improvement. Different studies have pointed to evaluating the quality of images affected by geometrical distortions as a challenge for current image quality metrics. In this work, we introduce the Colourlab Image Database: Geometric Distortions (CID:GD) with 49 different reference images made specifically to evaluate image quality metrics. CID:GD is one of the first datasets which include three different types of geometrical distortions; seam carving, lens distortion, and image rotation. 35 state-ofthe-art image quality metrics are tested on this dataset, showing that apart from a handful of these objective metrics, most are not able to show a high performance. The dataset is available at <ext-link ext-link-type="url" xlink:href="http://www.colourlab.no/cid">www.colourlab.no/cid</ext-link>.


2015 ◽  
Vol 32 (S1) ◽  
pp. 63-71 ◽  
Author(s):  
Young Joo Suh ◽  
Young Jin Kim ◽  
Yoo Jin Hong ◽  
Hye-Jeong Lee ◽  
Jin Hur ◽  
...  

Neurosurgery ◽  
2019 ◽  
Vol 87 (4) ◽  
pp. 689-696 ◽  
Author(s):  
Serge Marbacher ◽  
Jenny C Kienzler ◽  
Itai Mendelowitsch ◽  
Donato D’Alonzo ◽  
Lukas Andereggen ◽  
...  

Abstract BACKGROUND Postoperative three-dimensional digital subtraction angiography (3D-DSA) is the gold standard in evaluating intracranial aneurysm (IA) remnants after clipping. Should intraoperative 3D-DSA image quality be equally good as postoperative 3D-DSA, it could supplant the latter as standard of care for follow-up of clipped IA. OBJECTIVE To directly compare the quality of assessment of clipped IA by intraoperative and postoperative 3D-DSA. METHODS From a prospective cohort of 221 consecutive patients who underwent craniotomy for IA treatment in a hybrid operating room, we retrospectively studied 26 patients who had both intraoperative and postoperative 3D-DSA imaging of their clipped aneurysm. Comparison of intraoperative and postoperative 3D-DSA images (blinded for review) included parameters that affected image quality and differences between the 2 periods. RESULTS In the 26 patients with 32 clipped IAs, the mean interval was 11 ± 7 mo between intraoperative and postoperative imaging 3D-DSA examinations. Reconstruction with multiple clips was used in 14 (44%) cases. Of 15 remnants, 9 (60%) were small (&lt;2 mm). In comparing intraoperative and postoperative 3D-DSA, no discordance or discrepancy in assessment of the surgical result was noted for any clipped IA, and overall imaging quality was excellent for both modalities. Factors affecting minor differences in image quality were not identified. CONCLUSION Compared with postoperative 3D-DSA, intraoperative 3D-DSA images achieved equally high quality and effective, immediate interpretation of the surgical clipping result. With comparable imaging quality and no discordant findings, intraoperative 3D-DSA could replace postoperative 3D-DSA to become the standard of care in IA surgery.


2013 ◽  
Vol 5 (3) ◽  
pp. 53-65 ◽  
Author(s):  
Lu Laijie ◽  
Yang Gaobo ◽  
Xia Ming

As a retouching tool, image sharpening can be applied as the final step to hide those possible forgery operations in an image. Unsharp masking (USM) is a popular sharpening method supported by most image editing software such as Adobe Photoshop. Several passive forensics methods have been presented for the detection of USM Sharpening. In this paper, an anti-forensic scheme for USM Sharpening is proposed to invalidate the existing forensic algorithms. It removes the overshoot artifacts in image edges and abrupt change in histogram ends. The effectiveness of the proposed method is proved by the experimental results on a large image database with various parameter settings. Comparisons are made among the unsharpened images, the sharpened images and the anti-forensic dithered image. Both the detection ability and image quality are used for its performance evaluation.


Author(s):  
N. Ponomarenko ◽  
V. Lukin ◽  
K. Egiazarian ◽  
J. Astola ◽  
M. Carli ◽  
...  

2021 ◽  
Vol 11 (10) ◽  
pp. 4661
Author(s):  
Aladine Chetouani ◽  
Marius Pedersen

An abundance of objective image quality metrics have been introduced in the literature. One important essential aspect that perceived image quality is dependent on is the viewing distance from the observer to the image. We introduce in this study a novel image quality metric able to estimate the quality of a given image without reference for different viewing distances between the image and the observer. We first select relevant patches from the image using saliency information. For each patch, a feature vector is extracted from a convolutional neural network model and concatenated at the viewing distance, for which the quality is predicted. The resulting vector is fed to fully connected layers to predict subjective scores for the considered viewing distance. The proposed method was evaluated using the Colourlab Image Database: Image Quality and Viewing Distance-changed Image Database. Both databases provide subjective scores at two different viewing distances. In the Colourlab Image Database: Image Quality we obtain a Pearson correlation of 0.87 at both 50 cm and 100 cm viewing distances, while in the Viewing Distance-changed Image Database we obtained a Pearson correlation of 0.93 and 0.94 at viewing distance of four and six times the image height. The results show the efficiency of our method and its generalization ability.


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