Hujoel Philippe, Hollender Lars, Bollen Anne-Marie, Young John D, Cunha-Cruz Joana, McGee Molly, Grosso Alex
Department of Dental Public Health Sciences, School of Dentistry University of Washington, Seattle, USA.
BMC Med Imaging. 2006 Jun 13;6:6. doi: 10.1186/1471-2342-6-6.
The thyroid is among the more radiosensitive organs in the body. The goal of this study was twofold: (1) to evaluate age-related changes in what is exposed to ionizing radiation in the neck area, and (2) to assess thyroid shield presence in cephalometric radiographs
Cephalometric radiographs at one academic setting were sampled and neck exposure was related to calendar year and patient's gender and age.
In the absence of shields, children have more vertebrae exposed than adults (p < 0.0001) and females have more neck tissue exposed inferior to the hyoid bone than males (p < 0.0001). The hyoid bone-porion distance increased with age (p <0.01). Thyroid shields were visible in 19% of the radiographs and depended strongly on the calendar year during which patient was seen (p-value <0.0001). Compared to adults, children were less likely to wear thyroid shields, particularly between 1973 and 1990 (1.8% versus 7.3% -p-value < 0.05) and between 2001 and 2003 (7.1% versus 42.9% -p-value < 0.05).
In the absence of a thyroid shield, children have more neck structure exposed to radiation than adults. In agreement with other reports, thyroid shield utilization in this study was low, particularly in children.
甲状腺是人体中对辐射较为敏感的器官之一。本研究的目的有两个：（1）评估颈部区域接受电离辐射的情况与年龄相关的变化，（2）评估头颅侧位片中甲状腺防护装置的使用情况。
在一个学术机构收集头颅侧位片，并将颈部受照情况与年份、患者性别和年龄相关联。
在未使用防护装置的情况下，儿童暴露的椎体比成人多（p<0.0001），女性舌骨下方暴露的颈部组织比男性多（p<0.0001）。舌骨-耳点间距随年龄增加（p<0.01）。在19%的X线片中可见甲状腺防护装置，且其使用情况在很大程度上取决于患者就诊的年份（p值<0.0001）。与成人相比，儿童佩戴甲状腺防护装置的可能性较小，尤其是在1973年至1990年期间（1.8%对7.3% - p值<0.05）以及2001年至2003年期间（7.1%对42.9% - p值<0.05）。
在未使用甲状腺防护装置的情况下，儿童颈部接受辐射的结构比成人多。与其他报告一致，本研究中甲状腺防护装置的使用率较低，尤其是在儿童中。
