Oral Imaging Center, Faculty of Medicine, School of Dentistry, KU Leuven, Kapucijnenvoer 7, Leuven B-3000, Belgium.
Forensic Sci Int. 2010 Sep 10;201(1-3):112-7. doi: 10.1016/j.forsciint.2010.04.041.
Recently developed portable dental X-ray units increase the mobility of the forensic odontologists and allow more efficient X-ray work in a disaster field, especially when used in combination with digital sensors. This type of machines might also have potential for application in remote areas, military and humanitarian missions, dental care of patients with mobility limitation, as well as imaging in operating rooms.
To evaluate radiographic image quality acquired by three portable X-ray devices in combination with four image receptors and to evaluate their medical physics parameters.
Images of five samples consisting of four teeth and one formalin-fixed mandible were acquired by one conventional wall-mounted X-ray unit, MinRay 60/70 kVp, used as a clinical standard, and three portable dental X-ray devices: AnyRay 60 kVp, Nomad 60 kVp and Rextar 70 kVp, in combination with a phosphor image plate (PSP), a CCD, or a CMOS sensor. Three observers evaluated images for standard image quality besides forensic diagnostic quality on a 4-point rating scale. Furthermore, all machines underwent tests for occupational as well as patient dosimetry.
Statistical analysis showed good quality imaging for all system, with the combination of Nomad and PSP yielding the best score. A significant difference in image quality between the combination of the four X-ray devices and four sensors was established (p<0.05). For patient safety, the exposure rate was determined and exit dose rates for MinRay at 60 kVp, MinRay at 70 kVp, AnyRay, Nomad and Rextar were 3.4 mGy/s, 4.5 mGy/s, 13.5 mGy/s, 3.8 mGy/s and 2.6 mGy/s respectively. The kVp of the AnyRay system was the most stable, with a ripple of 3.7%. Short-term variations in the tube output of all the devices were less than 10%. AnyRay presented higher estimated effective dose than other machines. Occupational dosimetry showed doses at the operator's hand being lowest with protective shielding (Nomad: 0.1 microGy). It was also low while using remote control (distance>1m: Rextar <0.2 microGy, MinRay <0.1 microGy).
The present study demonstrated the feasibility of three portable X-ray systems to be used for specific indications, based on acceptable image quality and sufficient accuracy of the machines and following the standard guidelines for radiation hygiene.
最近开发的便携式牙科 X 射线设备提高了法医牙科学者的机动性，并允许在灾难现场更有效地进行 X 射线工作，特别是与数字传感器结合使用时。这种类型的机器也可能具有在偏远地区、军事和人道主义任务、行动不便的患者的牙科护理以及手术室成像中的应用潜力。
评估三种便携式 X 射线设备与四种图像传感器组合获得的射线照相图像质量，并评估其医学物理参数。
使用常规壁挂式 X 射线设备 MinRay 60/70 kVp（用作临床标准）和三种便携式牙科 X 射线设备（AnyRay 60 kVp、Nomad 60 kVp 和 Rextar 70 kVp）获取由四个牙齿和一个福尔马林固定下颌组成的五个样本的图像，以及磷光图像板（PSP）、CCD 或 CMOS 传感器。三位观察者根据四点评分标准评估标准图像质量和法医诊断质量。此外，所有机器都接受了职业和患者剂量学测试。
统计分析表明，所有系统都具有良好的成像质量，Nomad 和 PSP 的组合得分最高。在四种 X 射线设备和四种传感器的组合之间建立了图像质量的显著差异（p<0.05）。为了患者安全，确定了曝光率，并确定了 MinRay 在 60 kVp 时、MinRay 在 70 kVp 时、AnyRay、Nomad 和 Rextar 的出口剂量率分别为 3.4 mGy/s、4.5 mGy/s、13.5 mGy/s、3.8 mGy/s 和 2.6 mGy/s。AnyRay 系统的 kVp 最稳定，纹波为 3.7%。所有设备的管输出短期变化均小于 10%。AnyRay 呈现出比其他机器更高的估计有效剂量。职业剂量学显示，在操作员手部使用防护屏蔽时剂量最低（Nomad：0.1 微Gy）。当使用遥控器时（距离>1m：Rextar <0.2 微Gy，MinRay <0.1 微Gy），剂量也很低。
本研究表明，根据可接受的图像质量和机器的充分准确性，并遵循辐射卫生标准指南，三种便携式 X 射线系统可用于特定适应症。
