Effects of aluminum-copper alloy filtration on photon spectra, air kerma rate and image contrast

Gonçalves, Andréa; Rollo, João Manuel Domingos de Almeida; Gonçalves, Marcelo; Haiter-Neto, Francisco; Bóscolo, Frab Norberto

doi:10.1590/s0103-64402004000300010

Cited by 5 publications

(4 citation statements)

References 15 publications

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“…The results show that foot radiography can be taken using one exposure parameter, decreases the time required for the process and also decreases the workload of the radiographer. Compensation filters cannot only reduce radiation dosages to patients by absorbing low energy radiation (Manninen et al, 1986), but they also improve radiographic image quality (Gonçalves et al, 2004). Our results show that the plastic wedge can compensate for bone density on phalange and metatarsal regions.…”

Section: Discussionmentioning

confidence: 74%

Effects of Plastic Wedges on Whole Foot Radiograph in Anteroposterior and Oblique Positions

Lorlorm¹,

Choiprasert²,

Tungjai³

et al. 2017

American Journal of Applied Sciences

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Abstract:The whole foot radiography may be taken twice with different exposure parameters. It produces two images in two radiation exposures; one is the metatarsal view of the phalange and the other is a tarsal view. The aim of this study was to study the effects of plastic wedges on whole foot radiography with one radiation exposure. The plastic wedge was developed from plastic wood. Whole foot phantom radiographic imaging was created in anteroposterior and oblique positions with and without plastic wedges mounted on the collimator of an X-ray machine. A radiation imaging plate was used as a transmitted-radiation receptor. The radiation exposure parameter was 54 kilo-voltage at 100 milliamperes for 0.02 sec. The results showed that the resolution of whole foot phantom radiographic imaging in both anteroposterior and oblique positions with plastic wedge mounted on a collimator of an X-ray machine was better than without plastic wedge mounted on collimator. Percentage of Coefficient Variance (%CV) of pixel value on radiographic imaging with plastic wedge mounted on collimator was less than without plastic wedge mounted on collimator. This finding suggests that plastic wedges can help improve image quality of whole foot radiography with one radiation exposure.

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Section: Discussionmentioning

confidence: 74%

Effects of Plastic Wedges on Whole Foot Radiograph in Anteroposterior and Oblique Positions

Lorlorm¹,

Choiprasert²,

Tungjai³

et al. 2017

American Journal of Applied Sciences

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“…The energy absorption coefficients in some fatty acids were studied in energy of 662 and 1115 keV by Bhandal et al [13]. The mass energy absorption coefficients and mass collision stopping powers for electrons in tumors were studied [14]. Shakhreet et al measured µ en /ρ of paraffin, wax, and gypsum at 662 keV photon energy [15].…”

Section: Introductionmentioning

confidence: 99%

Studies on mass attenuation coefficient, mass energy absorption coefficient, and kerma for Fe alloys at photon energies of 17.44 to 51.70 keV

Yılmaz¹,

Şahin²,

Demir³

2015

Turk J Phys

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Abstract:The mass attenuation coefficient ( µm) , the mass energy absorption coefficient ( µen/ρ) , and kerma relative to air were determined for some alloys, namely Fe 0. 44, 19.63, 22.10, 24.90, 32.06, 36.39, 37.26, 43.74, 44.48, 50.38, and 51.70 photon energies by using an HPGe detector with a resolution of 182 eV at 5.9 keV. The experimental results of µm were compared with the theoretical results. The theoretical values of µen/ρ were compared with the semiempirical values. It was observed that kerma values relative to air values were different in Fe-Ce and Fe-Ni alloys due to photoelectric cross sections depending on the atomic numbers of the material.

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“…2 Other factors, such as current, voltage of the tube and filtration of the X-ray beam, can also modify the number of photons in the X-ray beam, causing a modulation of the radiation spectrum that affects exposure dose and image quality. [3][4][5][6][7] The X-ray filters can decrease the exposure dose to radiation by removing those low-energy photons from the X-ray beam. The low-energy photons would be absorbed by the soft tissue of the patient without affecting useful diagnostic information.…”

Section: Introductionmentioning

confidence: 99%

“…11 For single-material filters, the selected filtration should have a K absorption edge (K-edge) below 20 keV, because if the K-edge is greater than 20 keV the ability to attenuate low-energy photons may be severely compromised. 12 In Gonçalves et al's study, 3 which also used an added filtration of Al Cu, a decrease in energy spectrum between 30 keV and 41 keV without losses in quality of image or increase in exposure time was observed. In other studies were added filters such as niobium, which changed the energy spectrum between 43.3 keV and 48 keV 7 and the samarium filter between 25 keV and 45 keV.…”

mentioning

confidence: 96%

Alternative X-ray filters for an intra-oral digital radiographic system

Stecke

Cruz²,

Almeida³

et al. 2012

Dentomaxillofacial Radiology

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Objective: The aim of this study was to evaluate the effect of the modulation of the radiation spectrum with the use of alternative X-ray filters in the quality of intra-oral digital images from storage phosphor plates. Methods: The radiographic exposures were performed in a GE 1000 X-ray machine (General Electric Co., Milwaukee, WI), operating at 65 kVp, 10 mA, 40 cm focus receptor distance using three different exposure times: 0.05 s, 0.16 s and 0.35 s. The control filter (GC) was 100% aluminium (Al) with a thickness of 1.5 mm. The tested filters were: G1, 97% Al and 3% copper (Cu) with 1.47 mm thickness; G2, 96% Al and 4% Cu with 1.53 mm thickness; G3, 95% Al and 5% zinc (Zn) with 1.56 mm thickness; G4, 98% Al and 2% Zn with 1.5 mm thickness; and G5, 95% Cu and 5% Zn with 1.6 mm thickness. For formation of the image, a 12-step Al wedge (each step with increments of 1 mm in thickness) was radiographed 10 times. Pixel values measured in digital images were converted into optical density (OD). Results: All replicates showed OD with high reproducibility (r . 0.95) for all exposure times and tested filters. In comparison between filters, statistically significant differences in density (p , 0.05) were observed. The OD curve of the G5 filter in all exposure times and G3 filter in an exposure time of 0.05 s showed changes in shape (p , 0.05). Conclusions: Excluding the G5 filter, all others tested filters can be used as a substitute for GC without losses in image quality.

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Effects of aluminum-copper alloy filtration on photon spectra, air kerma rate and image contrast

Cited by 5 publications

References 15 publications

Effects of Plastic Wedges on Whole Foot Radiograph in Anteroposterior and Oblique Positions

Effects of Plastic Wedges on Whole Foot Radiograph in Anteroposterior and Oblique Positions

Studies on mass attenuation coefficient, mass energy absorption coefficient, and kerma for Fe alloys at photon energies of 17.44 to 51.70 keV

Alternative X-ray filters for an intra-oral digital radiographic system

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