Department of Medical Physics, Hunter New England Imaging, John Hunter Hospital, New Lambton Heights, NSW, Australia.
Phys Eng Sci Med. 2021 Jun;44(2):377-385. doi: 10.1007/s13246-021-00985-5. Epub 2021 Mar 3.
The use of hand-held dental X-ray units is increasing within Australia since their portability is advantageous in applications such as aged care. However, proximity of the operator to the X-ray unit raises radiation safety concerns. The aim of this study was to evaluate operator radiation exposure and methods of dose reduction for the Rextar X camera-style hand-held dental X-ray unit. Leakage and scattered radiation were measured using a solid state detector. Scatter was generated using a Perspex head phantom. Measurements of scattered radiation dose as a function of distance were made with and without a lead acrylic scatter shield (0.6 mm Pb equivalence at 100 kVp) attached to the X-ray unit. Without the scatter shield, doses to the operator from a single adult maxillary molar X-ray exposure were 0.69, 0.78 and 0.47 µGy at the left hand, right hand and eyes respectively. With the scatter shield attached, doses were reduced to 0.25, 0.12 and 0.15 µGy respectively, corresponding to a dose reduction of 64, 85 and 68%. The contribution from leakage radiation was insignificant in comparison. It is highly unlikely that an operator would reach occupational dose limits when using the Rextar X hand-held dental X-ray unit, even without the scatter shield in place. Nevertheless, it is strongly recommended that the scatter shield is attached to keep operator doses as low as reasonably achievable. Use of the scatter shield additionally ensures compliance with the Australian legislative requirement for a protective barrier and is considered a preferable alternative to X-ray protective clothing.
澳大利亚越来越多地使用手持牙科 X 射线设备，因为其便携性在老年护理等应用中具有优势。然而，操作员与 X 射线设备的接近程度引起了辐射安全方面的关注。本研究的目的是评估 Rextar X 相机式手持牙科 X 射线设备的操作人员辐射暴露情况和降低剂量的方法。使用固态探测器测量泄漏和散射辐射。使用有机玻璃头部体模产生散射。在没有和有附加到 X 射线设备的铅丙烯酸散射屏蔽（在 100 kVp 时为 0.6mmPb 等效）的情况下，测量了散射辐射剂量随距离的变化。在没有散射屏蔽的情况下，单个上颌磨牙 X 射线曝光对操作员的手部、手部和眼部的剂量分别为 0.69、0.78 和 0.47µGy。安装散射屏蔽后，剂量分别降低至 0.25、0.12 和 0.15µGy，相应的剂量降低率为 64%、85%和 68%。相比之下，漏射线的贡献微不足道。即使没有散射屏蔽，操作员使用 Rextar X 手持牙科 X 射线设备也不太可能达到职业剂量限制。然而，强烈建议安装散射屏蔽，以将操作人员的剂量降至尽可能低。使用散射屏蔽还确保符合澳大利亚的防护屏障法规要求，并且被认为是 X 射线防护服的更优替代方案。
