Determining optimum wavelength of ultraviolet rays to pre-exposure of non-uniformity error correction in Gafchromic EBT2 films

• Autorzy: Katsuda T. , Gotanda R. , Gotanda T. , Akagawa T. , Tanki N. , Kuwano T. , Noguchi A. , Yabunaka K.

Identyfikatory

DOI

10.2478/pjmpe-2018-0002

• Języki publikacji: EN

Abstrakty

EN

Gafchromic films have been used to measure X-ray doses in diagnostic radiology such as computed tomography. The double-exposure technique is used to correct non-uniformity error of Gafchromic EBT2 films. Because of the heel effect of diagnostic x-rays, ultraviolet A (UV-A) is intended to be used as a substitute for x-rays. When using a UV-A light-emitting diode (LED), it is necessary to determine the effective optimal UV wavelength for the active layer of Gafchromic EBT2 films. This study evaluated the relation between the increase in color density of Gafchromic EBT2 films and the UV wavelengths. First, to correct non-uniformity, a Gafchromic EBT2 film was pre-irradiated using uniform UV-A radiation for 60 min from a 72-cm distance. Second, the film was irradiated using a UV-LED with a wavelength of 353-410 nm for 60 min from a 5.3-cm distance. The maximum, minimum, and mean ± standard deviation (SD) of pixel values of the subtraction images were evaluated using 0.5 inches of a circular region of interest (ROI). The highest mean ± SD (8915.25 ± 608.86) of the pixel value was obtained at a wavelength of 375 nm. The results indicated that 375 nm is the most effective and sensitive wavelength of UV-A for Gafchromic EBT2 films and that UV-A can be used as a substitute for x-rays in the double-exposure technique.

Słowa kluczowe

EN

ultraviolet ray wavelength; gafchromic films; computed tomography; diagnostic radiology; double-exposure technique

• Wydawca: Polskie Towarzystwo Fizyki Medycznej ; De Gruyter
• Czasopismo: Polish Journal of Medical Physics and Engineering
• Rocznik: 2018
• Tom: Vol. 24, Iss. 1
• Strony: 11--14
• Opis fizyczny: Bibliogr. 11 poz., rys., tab.

Twórcy

autor

Katsuda T.

• Faculty of Health Sciences, Butsuryo College of Osaka, 3-33, Otorikita-machi Nishi-ku, Sakai-city, Osaka, 593-8328, Japan

autor

Gotanda R.

• Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Okayama, Japan

autor

Gotanda T.

• Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Okayama, Japan

autor

Akagawa T.

• Department of Radiological Technology, Tokushima Red Cross Hospital, 103, Irinokuchi, Komatsujshima, Tokushima, 773- 8502, Japan

autor

Tanki N.

• Faculty of Health Sciences, Butsuryo College of Osaka, 3-33, Otorikita-machi Nishi-ku, Sakai-city, Osaka, 593-8328, Japan

autor

Kuwano T.

• Graduate School of Health Sciences, Okayama University, 2-5-1, Shikata-cyo, Kita-ku, Okayama-city, Okayama, 700-8558, Japan

autor

Noguchi A.

• Faculty of Health Sciences, Butsuryo College of Osaka, 3-33, Otorikita-machi Nishi-ku, Sakai-city, Osaka, 593-8328, Japan

autor

Yabunaka K.

• Graduate School of Medicine, the University of Tokyo, 7-3-1 Hongo, Bunkyou-Ku, Tokyo, 113-0033, Japan

Bibliografia

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• [2] Gotanda T, Katsuda T, Gotanda R, et al: Evaluation of effective energy using radiochromic film and a step-shaped aluminum filter. Australas Phys Eng Sci Med. 2011;34(2):213-222.
• [3] Gotanda R, Katsuda T, Gotanda T, et al: Computed tomography phantom for radiochromic film dosimetry. Australas Phys Eng Sci Med. 2007;30(3):194-199.
• [4] Katsuda T, Gotanda R. Dose Measuring Method and Phantom, and X-Ray Image Picking-up Device Used for the Dose Measuring Method, WIPO Patent Application WO/2008; 087952.
• [5] Lewis F. David: Radiochromic Film. Advanced Materials Group Ashland Specialty Ingredients 2014; Spain: April 2014.
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• [7] Katsuda T, Gotanda R, Gotanda T, et al. Comparing three UV wavelengths for pre-exposing Gafchromic EBT-2 and EBT-3 films. J Appl Clin Med Phys. 2015;16(5):449-457.
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• [9] Katsuda T, Gotanda R, Gotanda T, et al. Correction of nonuniformity error of Gafchromic EBT2 and EBT3. J Appl Clin Med Phys. 2016;17(3):41-51.
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