An in-house step-wedge phantom for the calibration of pixel values in CT localizer radiographs for water-equivalent diameter measurement

• Autorzy: Rif’ah Sitti M. , Anam Choirul , Sutanto Heri , Asiah Rin H. , Holid Heryani , Dougherty Geoff

Identyfikatory

DOI

10.2478/pjmpe-2023-0006

• Języki publikacji: EN

Abstrakty

EN

Introduction: To develop an in-house acrylic-based step-wedge phantom with several thickness configurations for calibrating computed tomography (CT) localizer radiographs in order to measure the water-equivalent diameter (D_w) and the size-specific dose estimate (SSDE). Method: We developed an in-house step-wedge phantom using 3 mm thick acrylic, filled with water. The phantom had five steps with thicknesses of 6, 12, 18, 24, and 30 cm. The phantom was scanned using a 64-slice Siemens Definition AS CT scanner with tube currents of 50, 100, 150, 200, and 250 mA. The relationship between pixel value (PV) and water-equivalent thickness (t_w) was obtained for the different step thicknesses. This was used to calibrate the CT localizer radiographs in order to measure D_w and SSDE. The results of D_w and SSDE from the radiographs were compared with those calculated from axial CT images. Results: The relationship between PV and t_w from CT localizer radiographs of the phantom step-wedge produced a linear relationship with R² > 0.990. The linear relationships of the D_w and SSDE values obtained from CT localizer radiographs and axial CT images had R² values > 0.94 with a statistical test of p-value > 0.05. The D_w difference between those from CT localizer radiographs and axial CT images was 3.7% and the SSDE difference between both was 4.3%. Conclusion: We have successfully developed a step-wedge phantom to calibrate the relationship between PV and t_w. Our phantom can be easily used to calibrate CT localizer radiographs in order to measure D_w and SSDE.

Słowa kluczowe

EN

CT; step-wedge; water-equivalent thickness; water-equivalent diameter; SSDE

• Wydawca: Polskie Towarzystwo Fizyki Medycznej ; De Gruyter
• Czasopismo: Polish Journal of Medical Physics and Engineering
• Rocznik: 2023
• Tom: Vol. 29, Iss. 1
• Strony: 50--57
• Opis fizyczny: Bibliogr. 27 poz., rys., tab.

Twórcy

autor

Rif’ah Sitti M.

• Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia

autor

Anam Choirul

• Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia

• https://orcid.org/0000-0003-0156-6797

autor

Sutanto Heri

• 1Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia

autor

Asiah Rin H.

• 1Department of Physics, Faculty of Sciences and Mathematics, Diponegoro University, Jl. Prof. Soedarto SH, Tembalang, Semarang 50275, Central Java, Indonesia

autor

Holid Heryani

• Installation of Radiology, Rumah Sakit Umum Daerah (RSUD) Kraton Pekalongan, Jl.Veteran No. 31, Padukuhan Kraton, Pekalongan City, 51116, Central Java , Indonesia

autor

Dougherty Geoff

• Department of Applied Physics and Medical Imaging, California State University Channel Islands, Camarillo, CA, USA

Bibliografia

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Uwagi

Opracowanie rekordu ze środków MEiN, umowa nr SONP/SP/546092/2022 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2022-2023).