In the People's Republic of China, there are several national guidelines for radiation protection to patients undergoing radiological examinations using x-ray.Section 7.6,one of themandatory sections of national standard of 'Radiological protection requirements for X-ray computed tomography GBZ165-2012' [1]states the mandatory out-of-field protection devices that should be provided to the patients when undergoing scan. The devices are lead rubber, half lead apron, lead collar and lead cap. To ensure appropriate radiation protection practice is followed, government official performs annual onsite inspection to count and assess the...

A female adult anthropomorphic phantom (702D CIRS ATOM)inserted withthermoluminescence dosimeters chips (LiF TLD100 Thermo Scientific) underwent CTchest by a 64-rowSiemens Somatom Definition AS. Radiation protective devices were applied (Figures 3 to 5)except for the first scan. Lead rubber collar was not tested in this study to mimic the local clinical practice. TLD chips were placed and sandwiched inside pre-drill organ holes of the phantom. At least three TLD chips were placed in each hole. All holes of an organ were placed with TLD chips (Fig...

Figure 7 gives an overview ofthe distribution of absorbed doses of the organs of our interest without protection devices usedto the absorbed doses of the abdominal organs located inside the field-of-view/ unshielded. The thyroid and the spleen have the highest absorbed doses. Absorbed doses decrease with the organs locate further away from thesurface of the phantomand the field-of-view. The brain, the eyes, the ovaries, the uterus and the bladder received 36 to 81µGy of absorbed doses in CT chest without any protection device. Figure 8...

Results of our phantom study do not support out-of-field protective devices would providefurther radiation dose reduction in the head and pelvic organs in performing CT chest. Results of our phantom study suggest using thyroid shielding in CT chest should be considered. Further study on the effect ofshielding material and design of thyroid shield to image quality is required (Fig 9). Our experiencesfrom this phantom study, as listed below,supports the existing radiation protection practice in our department, i.e. applying a half lead skirt on patient's pelvis...

A. Chau; Hong Kong/HK - nothing to disclose J. Cheung; Hong Kong/HK - nothing to disclose C. T. P. Chan; Hong Kong/HK - nothing to disclose C. He; Shenzhen/CN - nothing to disclose J. Wang; Shenzhen/CN - nothing to disclose

National Health and Family Plan Commission of the People’s Republic of China, GB165-2012 Radiological protection requirements for X-ray computed tomography, 2012. http://www.nhc.gov.cn/wjw/pcrb/wsbz.shtml/. (Accessed 24 Dec 2019).