Contrast-to-noise ratio in magnification mammography: a Monte Carlo study

Koutalonis, M; Delis, Harry; Spyrou, George M.; Costaridou, Lena; Tzanakos, G.; Panayiotakis, George

doi:10.1088/0031-9155/52/11/017

Cited by 23 publications

(26 citation statements)

References 25 publications

(37 reference statements)

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“…simulated lesions) for irradiation. This particular approximation has been validated in a previous study by the authors, both for contact and magnification geometries, and proved to have only minor effects on the resulting measured values [5]. Furthermore, this situation has similarities to the clinical magnification imaging procedure where only a selected region-of-interest of the breast is irradiated.…”

Section: Simulation Of the Proceduressupporting

confidence: 61%

“…The specific spectrum was found to provide the best overall performance for the simulation conditions considered, when compared with other anode/filter material combinations, and is representative of those used clinically for producing magnification images in mammography [5].…”

Section: Simulation Of the Proceduresmentioning

confidence: 96%

“…An automatic exposure control (AEC) system was simulated to mimic the mammographic clinical process and match the data from previous studies by the authors [5,8]. The process consisted of adjusting the X-ray photon fluence, for each exposure condition considered, to deliver a 2 mR exposure at the image plane (for the CNR study) and a 5 mR exposure (for the spatial resolution study) for the field size considered and for both contact and magnification modes.…”

Section: Simulation Of the Proceduresmentioning

confidence: 99%

“…The CNR increases with the degree of magnification, particularly for low degrees (increase of 75% between degrees 1.0 and 1.4) [5]. By contrast, a major disadvantage of magnification is the additional and significantly high dose of radiation delivered to the breast compared with the contact case.…”

mentioning

confidence: 97%

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Can electronic zoom replace magnification in mammography? A comparative Monte Carlo study

Koutalonis¹,

Delis²,

Pascoal³

et al. 2010

BJR

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ABSTRACT. Magnification, which is considered to be a relatively high "dose cost" mammographic technique, is a complementary examination performed on women exhibiting breast complaints or abnormalities. Particular attention is given to the imaging procedure as the primary aim is to confirm the existence of suspected abnormalities, despite the additional dose. The introduction of post-processing capabilities and the widespread use of digital mammography promoted some controversy in the last decades on whether electronic zoom performed on the derived initial screening mammogram can effectively replace this technique. This study used Monte Carlo simulation methods to derive simulated screening mammograms produced under several exposure conditions, aiming to electronically magnify and compare them to the corresponding magnification mammograms. Comparison was based on quantitative measurements of image quality, namely contrast to noise ratio (CNR) and spatial resolution. Results demonstrated that CNR was higher for geometric magnification compared to the case of electronic zooming. The percentage difference was higher for lesions of smaller radius and achieved 29% for 0.10 mm details. Although spatial resolution is maintained high in the zoomed images, when investigating microcalcifications of 0.05 mm radius or less, only with geometric magnification can they be visualised.

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Section: Simulation Of the Proceduressupporting

confidence: 61%

Section: Simulation Of the Proceduresmentioning

confidence: 96%

Section: Simulation Of the Proceduresmentioning

confidence: 99%

mentioning

confidence: 97%

See 2 more Smart Citations

Can electronic zoom replace magnification in mammography? A comparative Monte Carlo study

Koutalonis¹,

Delis²,

Pascoal³

et al. 2010

BJR

Self Cite

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“…Additionally, Monte Carlo simulation has proven to be the most suitable and strong theoretical tool for the computation of x-ray spectra in complex geometries. Many mammography studies have used MC method for breast glandular dose calculations and its realtion to beam quality indexes like HVL (8)(9)(10)(11) (14). In this study, tungsten (W) anode material and rhodium (Rh) filter have been investigated for tube potentials between 26-32 kV and results compared with the available experimental and Monte Carlo result in literature (15).…”

Section: Introductionmentioning

confidence: 99%

Assessment of MCNPX Monte Carlo Code for Absorbed Dose Calculations in Mammogarphy Examination

Tekın¹,

Mesbahi²,

Singh³

et al. 2017

AKU-J. Sci. Eng.

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Introduction: This study aimed to investigate capabities of MCNPX monte carlo code for calculations of average absorbed dose in a breast phantom during mammography examination. Also, the effect of tube voltage and breast thickness on absorbed dose was determined by using Monte carlo method. Obtained HVL values were found to be comparable with experimental results and available Monte Carlo results. Thus, validated simulation setup has been used for investigation of average absorbed dose in a %50-%50 grandular-adipose breast phantom. Results: Our calculated results was consistent with the previous studies and our MC model was validated. The results showed that changing tube voltage from 26 to 32 kV leads to about 4 times increase in breast dose. While increasing breast thick ness from 2 to 5 cm results in 1.6 times higer dose to breast. Conclusion: It can concluded that the breast recieved dose depends strongly beam quality and breast thickness. Our modeling using MCNPX can be used future dosimteric studies concering breast dose investigations in mamograpgy examinations. Mamografi Çekimlerinde Absorbe Doz Hesaplamaları için MCNPX Monte Carlo Kodunun Değerlendirilmesi

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Deciphering the Reaction Mechanism of Lithium–Sulfur Batteries by In Situ/Operando Synchrotron‐Based Characterization Techniques

Yan

Cheng

Zhang

et al. 2019

Advanced Energy Materials

103

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have been the dominant energy storage devices for portable electronic devices and electric vehicles since 1990s. [1] However, the highest energy densities of LIBs are approaching their theoretical limits, hindering the widespread application of LIBs in a variety of emerging mobile transport applications. Therefore, advanced battery systems with high energy density and low cost that go beyond conventional LIBs are highly required. [2] Among different candidates of nextgeneration energy storage systems, lithium-sulfur (Li-S) batteries have attracted remarkable attention because of the high theoretical specific capacity of 1675 mAh g −1 and specific energy density of 2600 Wh kg −1 . [2g,3] Moreover, sulfur also has the advantages of nature abundance, nontoxicity, environmental benignity, and low cost. Therefore, Li-S batteries are considered as one of the most-promising candidates for next-generation electrochemical energy storage systems for electric vehicles and large-scale grids. [2b,c,4] For a typical Li-S battery, it is composed of lithium metal anode, organic electrolyte, and sulfur composite cathode (Figure 1a). During the discharge process, sulfur is reduced first to high-order polysulfides Li 2 S x (4 ≤ x ≤ 8) and then to low-order polysulfides Li 2 S x (1 ≤ x < 4). For Li-S batteries using ether-based organic electrolyte, there are two discharge plateaus at 2.3 and 2.1 V (Figure 1b), which correspond to the transformations of sulfur to Li 2 S 4 and Li 2 S 4 to Li 2 S, respectively. During the following charge process, Li 2 S is oxidized to elemental sulfur via the formation of intermediate lithium polysulfides.Despite the above-mentioned advantages, the practical application of Li-S batteries is still facing numerous challenges. For one thing, both sulfur and full discharge product Li 2 S are electronically and ionically insulating, resulting in low rate capability and low energy density. In addition, the formation and growth of Li 2 S on the surface of sulfur electrode during the discharge process can further impede the lithiation of sulfur. For another thing, the intermediate products, i.e., lithium polysulfides, have a high solubility in the organic electrolytes, resulting in the notorious "shuttle effect," low Coulombic efficiency, and passivation of the lithium metal electrode with insoluble Li 2 S/Li 2 S 2 . [2b,c,5] Since the concentration of dissolved Lithium-sulfur (Li-S) batteries have received extensive attention as one of the most promising next-generation energy storage systems, mainly because of their high theoretical energy density and low cost. However, the practical application of Li-S batteries has been hindered by technical obstacles arising from the polysulfide shuttle effect and poor electronic conductivity of sulfur and discharge products. Therefore, it is of profound significance for understanding the underlying reaction mechanism of Li-S batteries to circumvent these problems and improve the overall battery performance. Advanced characterization techniques, especially synchrot...

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Contrast-to-noise ratio in magnification mammography: a Monte Carlo study

Cited by 23 publications

References 25 publications

Can electronic zoom replace magnification in mammography? A comparative Monte Carlo study

Can electronic zoom replace magnification in mammography? A comparative Monte Carlo study

Assessment of MCNPX Monte Carlo Code for Absorbed Dose Calculations in Mammogarphy Examination

Deciphering the Reaction Mechanism of Lithium–Sulfur Batteries by In Situ/Operando Synchrotron‐Based Characterization Techniques

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