Image noise in high-resolution rear-projection screens

Author(s):  
Brent Larson ◽  
Matthew B. Dubin ◽  
Aleksandra Kolosowsky ◽  
Tim Flegal
2021 ◽  
pp. 20200553
Author(s):  
Yuki Sakai ◽  
Erina Kitamoto ◽  
Kazutoshi Okamura ◽  
Masato Tatsumi ◽  
Takashi Shirasaka ◽  
...  

Objectives: This study aimed to improve the impact of the metal artefact reduction (MAR) algorithm for the oral cavity by assessing the effect of acquisition and reconstruction parameters on an ultra-high-resolution CT (UHRCT) scanner. Methods: The mandible tooth phantom with and without the lesion was scanned using super-high-resolution, high-resolution (HR), and normal-resolution (NR) modes. Images were reconstructed with deep learning-based reconstruction (DLR) and hybrid iterative reconstruction (HIR) using the MAR algorithm. Two dental radiologists independently graded the degree of metal artefact (1, very severe; 5, minimum) and lesion shape reproducibility (1, slight; 5, almost perfect). The signal-to-artefact ratio (SAR), accuracy of the CT number of the lesion, and image noise were calculated quantitatively. The Tukey-Kramer method with a p-value of less than 0.05 was used to determine statistical significance. Results: The HRDLR visual score was better than the NRHIR score in terms of degree of metal artefact (4.6 ± 0.5 and 2.6 ± 0.5, p < 0.0001) and lesion shape reproducibility (4.5 ± 0.5 and 2.9 ± 1.1, p = 0.0005). The SAR of HRDLR was significantly better than that of NRHIR (4.9 ± 0.4 and 2.1 ± 0.2, p < 0.0001), and the absolute percentage error of the CT number in HRDLR was lower than that in NRHIR (0.8% in HRDLR and 23.8% in NRIR). The image noise of HRDLR was lower than that of NRHIR (15.7 ± 1.4 and 51.6 ± 15.3, p < 0.0001). Conclusions: Our study demonstrated that the combination of HR mode and DLR in UHRCT scanner improved the impact of the MAR algorithm in the oral cavity.


1989 ◽  
Vol 35 (3) ◽  
pp. 325-333 ◽  
Author(s):  
M. Ohsawa ◽  
H. Yoshikawa ◽  
M. Shiomi ◽  
T. Watanabe ◽  
S. Sakurai ◽  
...  

1993 ◽  
Vol 1 (1) ◽  
pp. 23 ◽  
Author(s):  
Michitaka Ohsawa ◽  
Makoto Onozawa ◽  
Kohji Hirata ◽  
Toshimitsu Watanabe ◽  
Yuichiro Kimura ◽  
...  

2006 ◽  
Vol 187 (3) ◽  
pp. 618-622 ◽  
Author(s):  
Hong Il Ha ◽  
Hyun Woo Goo ◽  
Joon Beom Seo ◽  
Jae-Woo Song ◽  
Jin Seong Lee

2000 ◽  
Author(s):  
Feng-Chao Chung ◽  
Fang-Chuan Ho ◽  
Yi-Ling Wu

1967 ◽  
Vol 31 ◽  
pp. 45-46
Author(s):  
Carl Heiles

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.


2019 ◽  
Vol 42 ◽  
Author(s):  
J. Alfredo Blakeley-Ruiz ◽  
Carlee S. McClintock ◽  
Ralph Lydic ◽  
Helen A. Baghdoyan ◽  
James J. Choo ◽  
...  

Abstract The Hooks et al. review of microbiota-gut-brain (MGB) literature provides a constructive criticism of the general approaches encompassing MGB research. This commentary extends their review by: (a) highlighting capabilities of advanced systems-biology “-omics” techniques for microbiome research and (b) recommending that combining these high-resolution techniques with intervention-based experimental design may be the path forward for future MGB research.


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