TY - JOUR
T1 - Breast exposure reduction using organ-effective modulation on chest CT in Asian women
AU - Ota, Joji
AU - Yokota, Hajime
AU - Takishima, Hazuki
AU - Takada, Akiyo
AU - Irie, Ryosuke
AU - Suzuki, Yuka
AU - Nagashima, Takeshi
AU - Horikoshi, Takuro
AU - Chida, Koichi
AU - Masuda, Yoshitada
AU - Uno, Takashi
PY - 2019/10
Y1 - 2019/10
N2 - Purpose: Organ-effective modulation (OEM) is a mechanism to reduce radiation dose to selected organs on computed tomography (CT). The purpose of this study was to measure radiation dose to the breast in Asian patients undergoing chest CT and to clarify the degree of exposure reduction. Method: We randomly selected 60 female patients undergoing non-contrast chest CT after breast cancer surgery. To measure radiation dose, an optically stimulated luminescence dosimeter had been attached directly to the gown over the nonoperated breast in 30 patients. Radiologists evaluated the image quality with and without OEM. In order to clarify the characteristics of OEM, the effects of angle and object size were measured using a phantom and an ionization chamber dosimeter. Results: The OEM group received 9.1 ± 1.9 mGy and the non-OEM group received 10.7 ± 2.4 mGy. OEM reduced the exposure by 12.2% (P < 0.01). OEM caused no reduction in diagnostic quality. In the phantom study, the results of the angle effect were 3.2%, 11.2%, 28.7%, 31.3, 25.9%, 14.9% and 6.0% dose reductions at −90, −60, −30, 0, 30, 60 and 90°, respectively. The effect of the subject thickness was 3.7%, 17.5%, 30.2%, 31.7%, and 34.1% at 16, 20, 24, 28 and 32 cm diameters, respectively. Conclusions: OEM is a useful mechanism for reducing radiation exposure to the breast without affecting diagnostic imaging quality. The reduction rate correlated negatively with body habitus.
AB - Purpose: Organ-effective modulation (OEM) is a mechanism to reduce radiation dose to selected organs on computed tomography (CT). The purpose of this study was to measure radiation dose to the breast in Asian patients undergoing chest CT and to clarify the degree of exposure reduction. Method: We randomly selected 60 female patients undergoing non-contrast chest CT after breast cancer surgery. To measure radiation dose, an optically stimulated luminescence dosimeter had been attached directly to the gown over the nonoperated breast in 30 patients. Radiologists evaluated the image quality with and without OEM. In order to clarify the characteristics of OEM, the effects of angle and object size were measured using a phantom and an ionization chamber dosimeter. Results: The OEM group received 9.1 ± 1.9 mGy and the non-OEM group received 10.7 ± 2.4 mGy. OEM reduced the exposure by 12.2% (P < 0.01). OEM caused no reduction in diagnostic quality. In the phantom study, the results of the angle effect were 3.2%, 11.2%, 28.7%, 31.3, 25.9%, 14.9% and 6.0% dose reductions at −90, −60, −30, 0, 30, 60 and 90°, respectively. The effect of the subject thickness was 3.7%, 17.5%, 30.2%, 31.7%, and 34.1% at 16, 20, 24, 28 and 32 cm diameters, respectively. Conclusions: OEM is a useful mechanism for reducing radiation exposure to the breast without affecting diagnostic imaging quality. The reduction rate correlated negatively with body habitus.
KW - Optically stimulated luminescence
KW - Organ based tube current modulation
KW - Organ-effective modulation
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U2 - 10.1016/j.ejrad.2019.108651
DO - 10.1016/j.ejrad.2019.108651
M3 - Article
C2 - 31525679
AN - SCOPUS:85072068989
VL - 119
JO - European Journal of Radiology
JF - European Journal of Radiology
SN - 0720-048X
M1 - 108651
ER -