scholarly journals Automatic exposure compensation in intraoral digital radiography: effect on the gray values of dental tissues

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Evelyn Rute Carneiro Maciel ◽  
Eduarda Helena Leandro Nascimento ◽  
Hugo Gaêta-Araujo ◽  
Maria Luiza dos Anjos Pontual ◽  
Andrea dos Anjos Pontual ◽  
...  
Keyword(s):  
Digital Radiography ◽  
Exposure Time ◽  
Titanium Implant ◽  
High Density ◽  
Regions Of Interest ◽  
Dental Tissues ◽  
Exposed Region ◽  
Imagej Software ◽  
Gray Values ◽  
Molar Region

Abstract Background This study aimed to investigate the effect of automatic exposure compensation (AEC) of intraoral radiographic systems on the gray values of dental tissues in images acquired with or without high-density material in the exposed region using different exposure times and kilovoltages. The influence of the distance of the high-density material was also investigated. Methods Radiographs from the molar region of two mandibles were obtained using the RVG 6100 and the Express systems, operating at 60 and 70 kV and 0.06, 0.10, and 0.16 s. Subsequently, a titanium implant was inserted in the premolar’s socket and other images were acquired. Using the ImageJ software, two regions of interest were determined on the enamel, coronary dentine, root dentine, and pulp of the first and second molars to obtain their gray values. Results In the RVG 6100, the implant did not affect the gray values (p > 0.05); the increase in kV decreased it in all tissues (p < 0.05), and the exposure time affected only the root dentine and pulp. In the Express, only enamel and coronary dentine values changed (p < 0.05), decreasing with the implant presence and/or with the increase in exposure factors. The distance of the implant did not affect the results (p > 0.05). Conclusions AEC’s performance varies between the radiographic systems. Its effect on the gray values depends not only on the presence or absence of high-density material but also on the kV and exposure time used.

scholarly journals Analysis of the reproducibility of the gray values and noise of a direct digital radiography system

2015 ◽  
Vol 29 (1) ◽  
pp. 1-5
Author(s):  
Marcelo Lupion POLETI ◽  
Thais Maria Freire FERNANDES ◽  
Renata Cordeiro TEIXEIRA ◽  
Ana Lúcia Alvares CAPELOZZA ◽  
Izabel Regina Fischer RUBIRA-BULLEN
Keyword(s):  
Digital Radiography ◽  
Digital Radiography System ◽  
Radiography System ◽  
Gray Values

Widths and shifts of argon-II lines in a pulsed arc

1968 ◽  
Vol 46 (9) ◽  
pp. 1083-1086 ◽  
Author(s):  
A. J. Barnard ◽  
H. G. James ◽  
C. R. Neufeld
Keyword(s):  
Exposure Time ◽  
High Density ◽  
The Other ◽  
Arc Plasma ◽  
And Shifts ◽  
Pulsed Arc

The spectrum of a high-density arc plasma was photographed with a 15 μs exposure time. The widths and shifts of 17 Ar-II lines were measured. While most lines have small blue shifts, the 4104 and 4278 Å lines have substantial red shifts. These two lines are also twice as wide as the other lines.

‘Terrestrial lava tubes as analogues for Mars – a review of the mineralogy and biosignatures of lava tubes from Iceland and the Terceira islands.’

2021 ◽  
Author(s):  
Mahid Ahmed ◽  
Nina Kopacz ◽  
Inge Loes ten Kate
Keyword(s):  
Regions Of Interest ◽  
Lava Tube ◽  
Lava Tubes ◽  
Thin Sections ◽  
The North ◽  
Point Analysis ◽  
Alteration Processes ◽  
Specific Alteration ◽  
Imagej Software ◽  
Areas Of Interest

&lt;p&gt;Lava tubes have been detected on Mars and because of their subsurface nature are shielded from the harsh conditions at the surface. If water intersects with the Martian lava tubes, a life nurturing environment may exist locally in these tubes. Lava tubes on Iceland and the Azores may support similar conditions as lava tubes on Mars and have been shown to contain a wide variety of microbes. [Planetary Analogues and Lava Tube ] (PELE) field expeditions have been setup to understand the relationship between microbes and susbtrate and the preservation of microbes in deeptime within these systems. Within such systems biogenic and hydrothermal alteration processes are not necessarily mutually exclusive and a good understanding of the mineralogy helps distinguish one from the other. Here, I have performed an analytical study analysing basalt mineralogy from recent lava flows from Iceland and Azores islands, attempting to distinguish between biogenic and hydrothermal signatures. I used a workflow of semi quantitative analysis using viewing thin sections under a light microscope to understand textural information. This was supplemented by &amp;#160;ImageJ software and using SEM+EDX for point analysis of regions of interest to shed light on our areas of interest. My results showed some ambiguous features linked to alteration in a sample in the north of Iceland related to clays or spherulites, in the Azores vesicle infill of clays or devitrified glass were seen with potential bio signatures including carbon,calcum and phosphorous. These results may indicate environmental factors leading to location specific alteration or related to lava rock mineralogy. Contamination effects cannot be ignored and must be taken into consideration when reviewing these results. Overall these analyses will contribute to the larger PELE outcome by providing a complimentary workflow that can be used to assess biosignatures and specific regions of interest within lava tube rocks.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

scholarly journals The Use of Colors as an Alternative to Size in Mold Growth Studies

2018 ◽  
Author(s):  
Edgar Cambaza ◽  
Shigenobu Koseki ◽  
Shuso Kawamura
Keyword(s):  
Color Change ◽  
Fungal Growth ◽  
Area Measurement ◽  
Mold Growth ◽  
Growth Studies ◽  
Closed Systems ◽  
Imagej Software ◽  
Gray Values ◽  
Yeast Extract Agar ◽  
Rgb System

Size-based fungal growth studies have limitations. For example, the growth in size stops in closed systems once it reaches the borders and poorly describes the metabolic status, especially in the stationary phase. This might lead mycotoxin studies to unrealistic results. Color change could be a viable alternative as pigments are results of the mold&rsquo;s metabolic activity. This study aimed to verify the possibility of using gray values and the RGB system to analyze the growth of Fusarium graminearum. It consisted color and area measurement using the ImageJ software for specimens grown in yeast extract agar (YEA). The results suggest the usability of color and gray values as reliable tools to analyze the growth of F. graminearum.

scholarly journals Analysis of the Gray-Value Reproducibility and Noise of a Direct Digital Radiography System

2019 ◽  
Vol 21 (1) ◽  
pp. 74
Author(s):  
Marcelo Lupion Poleti ◽  
Jaqueline Akemi Yamashita ◽  
Marcelo Estevam ◽  
Tânia Christina Simões ◽  
Paulo Henrique Rossato
Keyword(s):  
Digital Radiography ◽  
Bone Lesion ◽  
System Quality ◽  
Radiographic Images ◽  
Digital Radiography System ◽  
Radiography System ◽  
X Ray Imaging ◽  
Digital Radiograph ◽  
Gray Values

A radiografia digital representa um grande avanço na radiologia bucomaxilofacial porque incorpora a tecnologia informática na captura, interpretação e arquivamento de imagens radiográficas. Estudos anteriores demonstraram que é possível usar os valores de cinza no diagnóstico e na proservação das lesões ósseas. No entanto, essas aplicações dependem da qualidade do sistema radiológico e do tempo de exposição. O objetivo deste estudo foi avaliar a reprodutibilidade do valor de cinza e o ruído produzido pelo sistema IDA da Dabi Atlante, um sistema de radiografia digital direto. As radiografias foram obtidas de maneira padronizada (70 kV, 7 mA e filtração de 2,2 mm) com um sensor digital direto e um penetrômetro colocados em um fantoma a uma distância de filme-foco de 30 cm. Dez imagens radiográficas consecutivas foram obtidas com tempos de exposição de 0,10-s, 0,15-s e 0,20-s. Os valores de cinza foram analisados em cinco regiões de interesse (ROIs): tecido ósseo (TO), tecido mole (TM) e três degraus do penetrômetro (Degrau 1, Degrau 2 e Degrau 3). Os valores de cinza médios diferiram significativamente entre os tempos de exposição (p <0,05) em todos as cinco ROIs. A ROI com maior variabilidade do valor de cinza (25,36%) e ruído (9,46%) foi TM. Em conclusão, a reprodutibilidade do valor de cinza e o ruído do sistema IDA variam entre áreas com radiolucência diferente. Assim, atenção especial é necessária para o diagnóstico e proservação de lesões radiolucentes devido à interferência dos valores cinza relativamente alta.Palavras-chave: Radiografia Dentária Digital. Reprodutibilidade dos Testes. Diagnóstico por Imagem. AbstractThe digital radiograph represents a great advance in oral maxillofacial radiology because it incorporates informatics technology in the capture, interpretation, and archiving of radiographic images. Previous studies have demonstrated that it is possible to use gray values in bone lesion diagnosis and follow-up. However, these applications depend on radiograph system quality and exposure time. The aim of this study was to evaluate the gray-value reproducibility and noise produced by Dabi Atlante’s IDA system, a direct digital radiography system. Radiographs were obtained in a standardized manner (70 kV, 7 mA, and 2.2-mm filtration) with a direct digital sensor and a stepwedge placed in a phantom at a 30-cm focus-film distance. Ten consecutive x-ray imaging series were completed at 0.10-s, 0.15-s, and 0.20-s exposure times. Gray values were analyzed in five regions of interest (ROIs): bone tissue (BT), soft tissue (ST), and three stepwedge steps (Step 1, Step 2, and Step 3). Mean gray values differed significantly across exposure times (p < .05) in all five ROIs. The ROI with the greatest gray-value variability (25.36%) and noise (9.46%) was ST. In conclusion, gray-value reproducibility and noise of the IDA system vary across areas with differing radiolucency. Thus, special attention is necessary for the diagnosis and follow-up of radiolucent lesions due to relatively high gray-value interference.Keywords: Radiography, Dental, Digital. Reproducibility of Results. Diagnostic Imaging.

scholarly journals Evaluation of Radiopacity of Bulk-fill Flowable Composites Using Digital Radiography

2016 ◽  
Vol 41 (4) ◽  
pp. 424-431 ◽  
Author(s):  
B Tarcin ◽  
B Gumru ◽  
S Peker ◽  
HS Ovecoglu
Keyword(s):  
Digital Radiography ◽  
Digital Imaging ◽  
Imaging System ◽  
International Standards ◽  
Equivalent Thickness ◽  
Standard Specimens ◽  
Phosphor Plate ◽  
International Standards Organization ◽  
Flowable Composites ◽  
Gray Values

SUMMARY New flowable composites that may be bulk-filled in layers up to 4 mm are indicated as a base beneath posterior composite restorations. Sufficient radiopacity is one of the several important requirements such materials should meet. The aim of this study was to evaluate the radiopacity of bulk-fill flowable composites and to provide a comparison with conventional flowable composites using digital imaging. Ten standard specimens (5 mm in diameter, 1 mm in thickness) were prepared from each of four different bulk-fill flowable composites and nine different conventional flowable composites. Radiographs of the specimens were taken together with 1-mm-thick tooth slices and an aluminum step wedge using a digital imaging system. For the radiographic exposures, a storage phosphor plate and a dental x-ray unit at 70 kVp and 8 mA were used. The object-to-focus distance was 30 cm, and the exposure time was 0.2 seconds. The gray values of the materials were measured using the histogram function of the software available with the system, and radiopacity was calculated as the equivalent thickness of aluminum. The data were analyzed statistically (p&lt;0.05). All of the tested bulk-fill flowable composites showed significantly higher radiopacity values in comparison with those of enamel, dentin, and most of the conventional flowable composites (p&lt;0.05). Venus Bulk Fill (Heraeus Kulzer) provided the highest radiopacity value, whereas Arabesk Flow (Voco) showed the lowest. The order of the radiopacity values for the bulk-fill flowable composites was as follows: Venus Bulk Fill (Heraeus Kulzer) ≥ X-tra Base (Voco) &gt; SDR (Dentsply DeTrey) ≥ Filtek Bulk Fill (3M ESPE). To conclude, the bulk-fill flowable restorative materials, which were tested in this study using digital radiography, met the minimum standard of radiopacity specified by the International Standards Organization.

A New Method for Quantitatively Evaluating Defects of the Green Body in Injection Moulding Based on X-Ray Digital Radiography

2013 ◽  
Vol 652-654 ◽  
pp. 2093-2098
Author(s):  
Wei Fang ◽  
Xin Bo He ◽  
Rui Jie Zhang ◽  
Xuan Hui Qu
Keyword(s):  
Density Distribution ◽  
Quantitative Evaluation ◽  
Digital Radiography ◽  
Injection Moulding ◽  
Particle Density ◽  
Dimensional Accuracy ◽  
Inference System ◽  
X Ray ◽  
Powder Content ◽  
Gray Values

Attempts have been made to develop a gray value-matching detection method for quantitative evaluation of defects and density of green parts in metal injection moulding, based on the analysis of X-ray digital radiography images. The results show that the range of gray values should be in about 1.4% when the dimensional accuracy is required within 0.3%, and voids are present where fluctuation of the gray value is larger than 10%. The quantitative evaluation of voids, powder content and density distribution through the gray value-matching can respectively predict severity of voids, shrinkage, and deformation in the sintering stage. Furthermore, the ability to detect defects and particle density distribution of this method allows for the development of an inference system to predict the optimal parameters.

Estimation of Exposure Time in Digital Radiography Applicable to Film Radiography

2021 ◽  
Vol 41 (5) ◽  
pp. 289-296
Author(s):  
Jin Wook Yang ◽  
Seo Ung Jeon ◽  
Kap Ho Cho ◽  
Mun Ho Nam
Keyword(s):  
Digital Radiography ◽  
Exposure Time

Effects of polymeric matrix on accelerated UV weathering properties of wood-plastic composites

Holzforschung ◽  
2012 ◽  
Vol 66 (8) ◽  
pp. 981-987 ◽  
Author(s):  
Chia-Huang Lee ◽  
Ke-Chang Hung ◽  
Yong-Long Chen ◽  
Tung-Lin Wu ◽  
Yi-Chi Chien ◽  
...  
Keyword(s):  
Exposure Time ◽  
High Density Polyethylene ◽  
Moisture Absorption ◽  
Surface Oxidation ◽  
Moisture Diffusion ◽  
High Density ◽  
Modulus Of Rupture ◽  
Wood Plastic Composites ◽  
Surface Cracking ◽  
Plastic Composites

Abstract The purpose of this work is to compare the weathering properties of different types of wood-plastic composites (WPCs) based on high-density polyethylene (HDPE), recycled high-density polyethylene (rHDPE-I and rHDPE-II), low-density polyethylene (LDPE), polypropylene (PP), recycled polypropylene (rPP), polystyrene (PS), and recycled polystyrene (rPS). The modulus of rupture (MOR) and modulus of elasticity (MOE) of all WPCs decreased with increasing exposure time of weathering. Of these, the rHDPE-II-based composite exhibited the highest MOR and MOE retention ratios after 2000 h of accelerated ultraviolet (UV) weathering, while the PS-based WPC had the lowest values. In addition, the carbonyl index difference (CID) of various WPCs increased significantly as a function of exposure time. Among them, the PS-based WPCs exhibited the most severe degradation due to photo-oxidation on the surface, while the degradation of PE-based WPCs was the mildest. These results are consistent with the change in the surface cracking and flexural properties of the composites. The PS-based WPCs also exhibited higher moisture diffusion coefficients. The mechanical behavior of WPCs after weathering is influenced by a combination of factors, such as surface oxidation, morphology changes, and moisture absorption.

Evaluation of the Radiopacities of Bulk-fill RestorativesUsing Two Digital Radiography Systems

2015 ◽  
Vol 40 (5) ◽  
pp. E197-E205 ◽  
Author(s):  
E Yasa ◽  
B Yasa ◽  
OS Aglarci ◽  
ET Ertas
Keyword(s):  
Digital Radiography ◽  
Complementary Metal Oxide Semiconductor ◽  
American National Standard Institute ◽  
Oxide Semiconductor ◽  
National Standard ◽  
X Ray ◽  
Cmos Sensor ◽  
Photostimulable Phosphor ◽  
The Mean ◽  
Gray Values

SUMMARY This study investigated the radiopacity values of bulk-fill restoratives by using two digital radiography systems. Nine bulk-fill restoratives and a conventional composite were used in the study. Six disc-shaped specimens were prepared from each of these materials, three each at thicknesses of 1 mm and 2 mm, and tooth slices with these same thicknesses were obtained. As a control, an aluminum step wedge varying in thickness from 0.5 to 10 mm in was used. Three specimens of each of the materials, together with the tooth slice and the aluminum step wedge, were placed over a complementary metal oxide semiconductor (CMOS) sensor and a storage photostimulable phosphor (PPS) plate system and exposed using a dental x-ray unit. The images were analyzed using a software program to measure the mean gray values (MGVs). Five measurements were obtained from each of the restorative materials, the enamel, the dentin, and the stepwedge. The MGVs were converted to the equivalent aluminum thicknesses. Three-way analysis of variance (ANOVA) was used to determine the significance of the differences among the groups. A Tukey test was applied for pairwise comparisons (p&lt;0.05). All composite-based restoratives were found to have greater radiopacities than enamel or dentin. Equia Fil had the lowest radiopacity value. Radiopacity increased as the thicknesses of the restorative material increased. The CMOS system showed significantly higher radiopacity values than the PSP system. In conclusion, all investigated bulk-fill restoratives passed the International Organization for Standardization and American National Standard Institute/American Dental Association requirements for radiopacity values when evaluated with the two digital radiography systems.

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