• Journal of the Korean Society of Radiology
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• v.12 no.4
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• pp.541-547
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• 2018

To evaluate the effect of dose and image quality for Chest Digital Tomosynthesis(CDT) using sensitivity and tube voltage(kV). CDT images of the phantom were acquired varying sensitivity 200, 320, 400 according to set tube voltage of 125 kV and 135 kV. The dose and Dose Area Product(DAP) according to change of sensitivity and kV were evaluated and Image quality was evaluated by PSNR, CNR, SNR using Image J. Dose were lowered 14~23% less than sensitivity 200, 125 kV and DAP were lowered 13~26% less than sensitivity 200, 125 kV. PSNR were over 27 dB, which were significant value and CNR, SNR were better as sensitivity value was lower. But there were different statistical significant to each item. CNR and SNR were not statistically significant at sensitivity 320, 135 kV(P>0.05). CDT can improve image quality with lower radiation dose using better than quality and correction power at digital radiography system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.212-218
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• 2020

There are dozens of different types of lesions that can be diagnosed through chest X-ray images, including Atelectasis, Cardiomegaly, Mass, Pneumothorax, and Effusion. Computed tomography(CT) test is generally necessary to determine the exact diagnosis and location and size of thoracic lesions, however computed tomography has disadvantages such as expensive cost and a lot of radiation exposure. Therefore, in this paper, we propose a deep learning algorithm for judging the presence or absence of lesions in chest X-ray images as the primary screening tool for the diagnosis of thoracic lesions. The proposed algorithm was designed by comparing various configuration methods to optimize the judgment of presence of lesions from chest X-ray. As a result, the evaluation rate of lesion presence of the proposed algorithm is about 1% better than the existing algorithm.

• Journal of radiological science and technology
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• v.38 no.4
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• pp.347-353
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• 2015

The purpose of this study is to suggest proper additional filtration by comparisons patient dose and image quality among additional filters in digital chest tomosynthesis (DTS). We measured the effective dose, dose area product (DAP) by changing thickness of Cu, Al and Ni filter to compare image quality by CD curve and SNR, CNR. Cu, Al and Ni exposure dose were similar thickness 0.3 mm, 3 mm and 0.3 mm respectively. The exposure dose using filter was decreased average about 33.1% than non filter. The DAP value of 0.3 mm Ni were decreased 72.9% compared to non filter and the lowest dose among 3 filter. The effective dose of 0.3 mm Ni were decreased 48% compared to 0.102 mSv effective dose of non filter. At the result of comparison of image quality through CD curve there were similar aspect graph among Cu, Al and Ni. SNR was decreased average 19.07%, CNR was average decreased 18.17% using 3 filters. In conclusion, Ni filtration was considered to be most suitable when considered comprehensive thickness, character, sort of filter, dose reduction and image quality evaluation in DTS.

• Journal of the Korean Society of Radiology
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• v.12 no.1
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• pp.23-30
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• 2018

To evaluate the effect of patient size on effective dose and image quality for Digital Chest Tomosynthesis(DTS) using additional 0.3 mm copper filtration. Eighty artificial nodules were placed in the thorax phantom("Lungman," Kyoto Kagaku, Japan), and Digital Chest Tomosynthesis(DTS) images of the phantom were acquired both with and without added 0.3 mm Cu filtration. To simulate patients of three sizes: small, average size and oversize, one or two 20-mm-thick layer of PMMA(polymethyl methacrylatek) blocks were placed on the phantom. The Effective dose was calculated using Monte Carlo simulations. Two evaluations of image quality methods have been employed. Three readers counted the number of nodules detected in the lung, and the measured contrast-to-noise ratios(CNRs) were used. Data were analyzed statistically. The ED reduced $26{\mu}Sv$ in a phantom, $33{\mu}Sv$ in one 20-mm-thick layer of PMMA block placed on the phantom, and $48{\mu}Sv$ in two 20-mm-thick layer of PMMA blocks placed on the phantom. The Effective dose(ED) differences between DTS with and without filtration were significant(p<0.05). In particular, when we used two 20-mm-thick layer of PMMA blocks placed on the phantom, the ED was significantly reduced by 36% compared with those without additional filtration. Nodule detection sensitivities were not different between with and without added filtration. Differences of CNRs were statistically insignificant(p>0.05). Use of additional filtration allows a considerable dose reduction during Digital Chest Tomosynthesis(DTS) without loss of image quality. In particular, additional filtration showed outstanding result for effective dose reduction on two 20-mm-thick layer of PMMA blocks placed on the phantom. It applies to overweight patients.