Computed tomography phantom for radiochromic film dosimetry.
To evaluate in detail the dose distribution during computed tomography (CT), a sheet roll CT dosimetry phantom (SRCT-P) with a radiochromic film (RF) was experimentally developed. The SRCT-P was made by rolling up a vinyl chloride sheet in a cylindrical shape to arbitrarily select the SRCT-P diameter, dose measurement position, and depth. The SRCT-P centre core consisted of a plastic hose in which a 10 mm acrylic bar with a RF was inserted. To determine the availability of the SRCT-P, the surface and centre doses (at a 5 mm radius) at each SRCT-P diameter (6-16 cm; every 2 cm) were measured. The ratios of the centre-to-surface doses (D(centre)/D(surface)) systematically increased, from 80 to 111%, for decreasing SRCT-P diameters, between 16 and 6 cm, respectively. The centre dose approached the surface dose as the SRCT-P diameter decreased. To use a RF for a CT dose measurement, further detailed research and analysis is necessary. However, this study has shown that a SRCT-P is useful and beneficial for the measurement of the dose distribution during a CT examination.
Graduate School of Health Sciences, Okayama University, Okayama, Japan. gotarumi1011@yahoo.co.jp
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Gotanda
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Katsuda
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Gotanda
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Eguchi
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Takewa
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Tabuchi
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Yatake
D004867:Equipment Design; D019544:Equipment Failure Analysis; D005373:Film Dosimetry / Q000295:instrumentation* / Q000379:methods; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation*