Backside Irradiation of Ultraviolet-A for Correcting Nonuniformity Error of Gafchromic XR-QA2 Films
Purpose: Radiochromic film is used for quality assurance and quality control of X-ray equipment in the diagnostic radiology. In addition, three-dimensional dose distribution of computed tomography (CT) is measured. To correct the nonuniformity and uncertainty of radiochromic films for dose measureme...
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| Format: | Article |
| Language: | English |
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Wolters Kluwer Medknow Publications
2024-12-01
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| Series: | Journal of Medical Physics |
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| Online Access: | https://journals.lww.com/10.4103/jmp.jmp_87_24 |
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| _version_ | 1841556543407915008 |
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| author | Nobuyoshi Tanki Sachiko Goto Toshizo Katsuda Rumi Gotanda Tatsuhiro Gotanda Tadao Kuwano |
| author_facet | Nobuyoshi Tanki Sachiko Goto Toshizo Katsuda Rumi Gotanda Tatsuhiro Gotanda Tadao Kuwano |
| author_sort | Nobuyoshi Tanki |
| collection | DOAJ |
| description | Purpose:
Radiochromic film is used for quality assurance and quality control of X-ray equipment in the diagnostic radiology. In addition, three-dimensional dose distribution of computed tomography (CT) is measured. To correct the nonuniformity and uncertainty of radiochromic films for dose measurement of CT, the films are preirradiated ultraviolet (UV)-A rays. There is a difference in the UV protection strength of radiochromic films. A concern exists about the effects of the UV-A irradiation intensity. We thus irradiated with UV-A rays from the backsides of the films to assess if backside irradiation was possible.
Materials and Methods:
Gafchromic XR-QA2 and RTQA2 were used in this study. The UV-A rays were simultaneously irradiated on the front and backsides of each film for 12 h. The yellow layer of each film was scanned and imaged. The average pixel values ± standard deviations (SDs) were compared. In the statistical analysis, a paired t-test was performed. To compare, the active-layer densities engendered by the UV-A rays. Calibration curve was created with 48 h of preirradiation of UV-A.
Results:
The mean pixel values ± SD for Gafchromic XR-QA2 on the front and backsides were 130.776 ± 0.812 and 81.015 ± 1.128, respectively. On the other hand, the mean pixel values ± SD for Gafchromic RTQA2 on the front and backsides were 62.299 ± 1.077 and 133.761 ± 1.365, respectively. The statistical results of the paired t-test were significantly different (P < 0.01) between both films. Fitting equation of the calibration curve is shown below. y = -390.47 ± 200 + (443.45 ± 10x80).5068 ± 0.0434.
Conclusion:
Based on the relationship between the sensitivity of the active layer to UV-A rays and the strength of UV protection on the surface, we concluded that backside irradiation is recommended for Gafchromic XR-QA2, and frontside irradiation is recommended for Gafchromic RTQA2. |
| format | Article |
| id | doaj-art-0295d0f9cee245b3a463bc29cef26bc0 |
| institution | Kabale University |
| issn | 0971-6203 1998-3913 |
| language | English |
| publishDate | 2024-12-01 |
| publisher | Wolters Kluwer Medknow Publications |
| record_format | Article |
| series | Journal of Medical Physics |
| spelling | doaj-art-0295d0f9cee245b3a463bc29cef26bc02025-01-07T07:19:03ZengWolters Kluwer Medknow PublicationsJournal of Medical Physics0971-62031998-39132024-12-0149456356710.4103/jmp.jmp_87_24Backside Irradiation of Ultraviolet-A for Correcting Nonuniformity Error of Gafchromic XR-QA2 FilmsNobuyoshi TankiSachiko GotoToshizo KatsudaRumi GotandaTatsuhiro GotandaTadao KuwanoPurpose: Radiochromic film is used for quality assurance and quality control of X-ray equipment in the diagnostic radiology. In addition, three-dimensional dose distribution of computed tomography (CT) is measured. To correct the nonuniformity and uncertainty of radiochromic films for dose measurement of CT, the films are preirradiated ultraviolet (UV)-A rays. There is a difference in the UV protection strength of radiochromic films. A concern exists about the effects of the UV-A irradiation intensity. We thus irradiated with UV-A rays from the backsides of the films to assess if backside irradiation was possible. Materials and Methods: Gafchromic XR-QA2 and RTQA2 were used in this study. The UV-A rays were simultaneously irradiated on the front and backsides of each film for 12 h. The yellow layer of each film was scanned and imaged. The average pixel values ± standard deviations (SDs) were compared. In the statistical analysis, a paired t-test was performed. To compare, the active-layer densities engendered by the UV-A rays. Calibration curve was created with 48 h of preirradiation of UV-A. Results: The mean pixel values ± SD for Gafchromic XR-QA2 on the front and backsides were 130.776 ± 0.812 and 81.015 ± 1.128, respectively. On the other hand, the mean pixel values ± SD for Gafchromic RTQA2 on the front and backsides were 62.299 ± 1.077 and 133.761 ± 1.365, respectively. The statistical results of the paired t-test were significantly different (P < 0.01) between both films. Fitting equation of the calibration curve is shown below. y = -390.47 ± 200 + (443.45 ± 10x80).5068 ± 0.0434. Conclusion: Based on the relationship between the sensitivity of the active layer to UV-A rays and the strength of UV protection on the surface, we concluded that backside irradiation is recommended for Gafchromic XR-QA2, and frontside irradiation is recommended for Gafchromic RTQA2.https://journals.lww.com/10.4103/jmp.jmp_87_24backside irradiationcomputed tomographyreflective type radiochromic filmultraviolet radiation |
| spellingShingle | Nobuyoshi Tanki Sachiko Goto Toshizo Katsuda Rumi Gotanda Tatsuhiro Gotanda Tadao Kuwano Backside Irradiation of Ultraviolet-A for Correcting Nonuniformity Error of Gafchromic XR-QA2 Films Journal of Medical Physics backside irradiation computed tomography reflective type radiochromic film ultraviolet radiation |
| title | Backside Irradiation of Ultraviolet-A for Correcting Nonuniformity Error of Gafchromic XR-QA2 Films |
| title_full | Backside Irradiation of Ultraviolet-A for Correcting Nonuniformity Error of Gafchromic XR-QA2 Films |
| title_fullStr | Backside Irradiation of Ultraviolet-A for Correcting Nonuniformity Error of Gafchromic XR-QA2 Films |
| title_full_unstemmed | Backside Irradiation of Ultraviolet-A for Correcting Nonuniformity Error of Gafchromic XR-QA2 Films |
| title_short | Backside Irradiation of Ultraviolet-A for Correcting Nonuniformity Error of Gafchromic XR-QA2 Films |
| title_sort | backside irradiation of ultraviolet a for correcting nonuniformity error of gafchromic xr qa2 films |
| topic | backside irradiation computed tomography reflective type radiochromic film ultraviolet radiation |
| url | https://journals.lww.com/10.4103/jmp.jmp_87_24 |
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