Abstract
This study aimed to determine the optimal radiographic conditions for detecting lesions on digital chest radiographs using an indirect conversion flat-panel detector with a copper (Cu) filter. First, we calculated the effective detective quantum efficiency (DQE) by considering clinical conditions to evaluate the image quality. We then measured the segmentation accuracy using a U-net convolutional network to verify the effectiveness of the Cu filter. We obtained images of simulated lung tumors using 10-mm acrylic spheres positioned at the right lung apex and left middle lung of an adult chest phantom. The Dice coefficient was calculated as the similarity between the output and learning images to evaluate the accuracy of tumor area segmentation using U-net. Our results showed that effective DQE was higher in the following order up to the spatial frequency of 2 cycles/mm: 120 kV + no Cu, 120 kV + Cu 0.1 mm, and 120 kV + Cu 0.2 mm. The segmented region was similar to the true region for mass–area extraction in the left middle lobe. The lesion segmentation in the upper right lobe with 120 kV + no Cu and 120 kV + Cu 0.1 mm was less successful. However, adding a Cu filter yielded reproducible images with high Dice coefficients, regardless of the tumor location. We confirmed that adding a Cu filter decreases the X-ray absorption efficiency while improving the signal-to-noise ratio (SNR). Furthermore, artificial intelligence accurately segments low-contrast lesions.
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References
UNSCEAR. Medical radical exposures. Sources and effects of ionizing radiation. UNSCER 2008 Report. New York: United Nations. Annex A; 2010
Oda N, Kurokawa Y, Uehara S, Sasaki N, Yamagata K, Yamazaki S, et al. Evaluation of 90 kV beam with 0.15-mm Cu filter in chest radiography using CsI-Flat panel detector. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2020;76:463–73. https://doi.org/10.6009/jjrt.2020_JSRT_76.5.463.
Oda N, Tabata Y, Mizuta M, Asada Y, Nakano T, Hara T, et al. Optimal beam quality in chest radiography using CsI-flat panel detector for detection of pulmonary nodules. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2021;77:335–43. https://doi.org/10.6009/jjrt.2021_JSRT_77.4.335.
Sun Z, Lin C, Tyan Y, Ng KH. Optimization of chest radiographic imaging parameters: A comparison of image quality and entrance skin dose for digital chest radiography systems. Clin Imaging. 2012;36:279–86. https://doi.org/10.1016/j.clinimag.2011.09.006.
Compagnone G, Baleni CM, Di Nicola E, et al. Optimisation of radiological protocols for chest imaging using computed radiography and flat-panel X-ray detectors. Radiol Med. 2013;118(4):540–54.
Vyborny C, Metz C, Doi K. Large area contrast prediction in screen-film systems. Proc Soc Photo Opt Instrum Eng. 1980;233:30–6.
Kawashima H, Ichikawa K, Kunitomo H. Relationship between radiation quality and image quality in digital chest radiography: Validation study using human soft tissue-equivalent phantom. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2021;77:255–62. https://doi.org/10.6009/jjrt.2021_JSRT_77.3.255.
Hamer OW, Sirlin CB, Strotzer M, Borisch I, Zorger N, Feuerbach S, et al. Chest radiography with a flat-panel detector: Image quality with dose reduction after copper filtration. Radiology. 2005;237:691–700. https://doi.org/10.1148/radiol.2372041738.
Asada Y, Suzuki S, Kobayashi K, Kato H, Igarashi T, Tsukamoto A, et al. Investigation of patient exposure doses in diagnostic radiography in 2011 questionnaire. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2013;69:371–9. https://doi.org/10.6009/jjrt.2013_jsrt_69.4.371.
Asada Y, Suzuki S, Kobayashi K, Kato H, Igarashi T, Tsukamoto A, et al. Summary of results of the patient exposures in diagnostic radiography in 2011 questionnaire-focus on radiographic conditions-. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2012;68:1261–8. https://doi.org/10.6009/jjrt.2012_jsrt_68.9.1261.
Kishimoto K, Ariga E, Ishigaki R, Imai M, Kawamoto K, Kobayashi K, et al. Study of appropriate dosing in consideration of image quality and patient dose on the digital radiography. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2011;67:1381–97. https://doi.org/10.6009/jjrt.67.1381.
Schaefer-Prokop CM, De Boo DW, Uffmann M, Prokop M. DR and CR: Recent advances in technology. Eur J Radiol. 2009;72:194–201. https://doi.org/10.1016/j.ejrad.2009.05.055.
IEC. Medical electrical equipment-Characteristics of digital X-ray imaging devices part1: Determination of detective quantum efficiency. ed. 1.0p. 62220–1; 2003
IEC. 62220–1–2 Medical electrical equipment-Characteristics of digital X-ray imaging devices Part 1–2: Determination of the detective quantum efficiency-Detectors used in mammography. 1st ed..O, 2007
Samei E, Ranger NT, Dobbins JT, Ravin CE. Effective dose efficiency: An application- specific metric of quality and dose for digital radiography. Phys Med Biol. 2011;56:5099–118. https://doi.org/10.1088/0031-9155/56/16/002.
Samei E, Ranger NT, Mackenzie A, Honey ID, Dobbins JT, Ravin CE. Detector or system? extending the concept of detective quantum efficiency to characterize the performance of digital radiographic imaging systems. Radiology. 2008;249:926–37. https://doi.org/10.1148/radiol.2492071734.
Bertolini M, Nitrosi A, Rivetti S, Lanconelli N, Pattacini P, Ginocchi V, et al. A comparison of digita1radiography systems in terms of effective detective quantum efficiency. Med Phys. 2012;39:2617–27. https://doi.org/10.1118/1.4704500.
Hirai.T, Korogi. Y, Arimura. H, et al. Intracranial aneurysms at MR angiography: effect of computer-aided diagnosis on radiologists’ detection performance. Radiology. 2005;237(2):605–10.
Sosna J, Morrin MM, Kruskal JB, Lavin PT, Rosen MP, Raptopoulos V. CT colonography of colorectal polyps: A metaanalysis. AJR Am J Roentgenol. 2003;181:1593–8. https://doi.org/10.2214/ajr.181.6.1811593.
Kawashita I. Development of computer-aided medical care support system based on image recognition/processing technique: from diagnostic support to medical support. Iyou Gazou Jyouhou Gakkai Zasshi. 2014;31:xviii–xxii.
Gulshan V, Peng L, Coram M, Stumpe MC, Derek W, Narayanaswamy A, et al. Development and validation of a deep learning algorithm for detection of diabetic retinopathy in retinal fundus photographs. JAMA. 2016;316(22):2402–10. https://doi.org/10.1001/jama.2016.17216.
IAEA Safety Series No. 1154, International basic safety standards for protection of radiation sources. Vienna: International Arts and Entertainment Alliance; 1994.
Japan network for research and information on medical exposures(J-RIME); 2020 - Japan DRLs 2020-. National Diagnostic Reference Levels in Japan. http://www.radher.jp/J-RIME/report/DRL2020_Engver.pdf
Hayashi H, Takegami K, Konishi Y, Fukuda I. Indirect method of measuring the scatter X-ray fraction using collimators in the diagnostic domain. Nihon Hoshasen Gijutsu Gakkai Zasshi. 2014;70:213–22. https://doi.org/10.6009/jjrt.2014_jsrt_70.3.213.
Tucker DM, Barnes GT, Chakraborty DP. Semiempirical model for generating tungsten target x-ray spectra. Med Phys. 1991;18:211–8. https://doi.org/10.1118/1.596709.
Berger MJ, Hubbell JH, Seltzer SM, et al. XCOM: Photon cross sections database. 1998;(NBSIR 87–3597), Inst.
Hiraoka T, Kato H. Physical beam quality of Titan 320 X-ray equipment, primary X-ray spectrum and air kerma. Radiol Sci. 2011;54:38–41.
Rnoneberger O, Fischer P, Brox T. U-net Convolutional networks for biomedical image segmentation Lecture Notes in Computer Sciences (including SubserLect Notes ArtifIntellLect Notes Bioinformatics). In: Navab N, Hornegger J, Wells WM, Frangi AF, editors. Medical image computing and computer-assisted intervention–MICCAI 2015: 18th International Conference, Munich, Germany, Proceedings, Part III. Cham: Springer International Publishing; 2015. p. 234–41.
Sahiner B, Pezeshk A, Hadjiiski LM, Wang X, Drukker K, Cha KH, et al. Deep learning in medical imaging and radiation therapy. Med Phys. 2019;46:e1–36. https://doi.org/10.1002/mp.13264.
Onodera S, Lee Y, Kawabata T. Dose reduction potential in dual-energy subtraction chest radiography based on the relationship between spatial-resolution property and segmentation accuracy of the tumor area. Acta IMEKO. 2022;11:1. https://doi.org/10.21014/acta_imeko.v11i2.1168.
Kijewski MF, Judy PF. The noise power spectrum of CT images. Phys Med Biol. 1987;32:565–75. https://doi.org/10.1088/0031-9155/32/5/003.
Riederer SJ, Pelc NJ, Chesler DA. The noise power spectrum in computed X-ray tomography. Phys Med Biol. 1978;23:446–54. https://doi.org/10.1088/0031-9155/23/3/008.
Onodera S, Lee Y, Tanaka Y. Evaluation of dose reduction potential in scatter-corrected bedside chest radiography using U-net. Radiol Phys Technol. 2020;13:336–47. https://doi.org/10.1007/s12194-020-00586-z.
Vyborny PC, Bunch HC, et al. Image quality in chest radiography. J ICRU. 2003;3:13.
Nasrullah N, Sang J, Alam M, Mateen M, Cai B, Hu H. Automated lung nodule detection and classification using deep learning combined with multiple strategies. Sensors (Basel). 2019;19(17):3722. https://doi.org/10.3390/s19173722.
Chiu H, Peng R, Lin Y, Wang T, Yang Y, Chen Y, et al. artificial intelligence for early detection of chest nodules in X-ray images. Biomedicines. 2022;10(11):2839. https://doi.org/10.3390/biomedicines10112839.
Rajaraman S, Folio L, Dimperio J, Alderson P, Antani S. Improved semantic segmentation of tuberculosis-consistent findings in chest X-rays using augmented training of modality-specific U-Net models with weak localizations. Diagnostics (Basel). 2021;11(4):616. https://doi.org/10.3390/diagnostics11040616.
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Onodera, S., Kondo, Y., Ishizawa, S. et al. Usefulness of copper filters in digital chest radiography based on the relationship between effective detective quantum efficiency and deep learning-based segmentation accuracy of the tumor area. Radiol Phys Technol 16, 299–309 (2023). https://doi.org/10.1007/s12194-023-00719-0
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DOI: https://doi.org/10.1007/s12194-023-00719-0