Momoniat H T, England A
Department of Radiology, Central Manchester & Manchester Children's Hospital NHS Foundation Trust, UK.
Directorate of Radiography, University of Salford, UK.
Radiography (Lond). 2017 Feb;23(1):55-59. doi: 10.1016/j.radi.2016.09.006. Epub 2016 Oct 6.
The aim of this study is to determine the accuracy of orbital X-rays, when using computed radiography (CR), in detecting ferromagnetic intra-ocular foreign bodies (IOFBs) prior to magnetic resonance imaging (MRI).
A total of 64 orbital X-rays of an anthropomorphic head phantom were acquired using CR. For each image 1, 2, 3, or 4, large, medium, or small IOFBs were fixed to the anterior surface of the left or right orbit. Each of the acquired images with an IOFB was duplicated in order to increase the sample size. A further 16 normal images (no IOFB) were also included in the sample. Observers were invited to review the images and were permitted to manually magnify and window the images to detect any IOFBs present on each image.
10 observers (4 radiographers; 4 reporting radiographers; 2 consultant radiologists) independently reviewed the images. The mean (SD) sensitivity and specificity were 72.1% (7.3%) and 99.2% (0.8%) for all observers, respectively. According to size the sensitivity in detecting small, medium and large IOFB were 46%, 76% and 93%, respectively. According to location, the lower lateral quadrants had the lowest sensitivity (53%) whereas the upper medial had the greatest (88%).
Findings from this study using CR support previous conclusions that conventional X-rays fail to detect metallic IOFBs in all cases. Diagnostic performance is governed by IOFB size and location.
本研究旨在确定在磁共振成像（MRI）之前使用计算机X线摄影（CR）时，眼眶X线在检测铁磁性眼内异物（IOFBs）方面的准确性。
使用CR采集了总共64张拟人头部模型的眼眶X线片。对于每张图像，将1个、2个、3个或4个大、中或小的IOFB固定在左眼眶或右眼眶的前表面。为了增加样本量，对每张带有IOFB的采集图像进行了复制。样本中还包括另外16张正常图像（无IOFB）。邀请观察者查看图像，并允许手动放大和调整图像窗口以检测每张图像上是否存在IOFB。
10名观察者（4名放射技师；4名报告放射科医生；2名放射科顾问医生）独立查看了这些图像。所有观察者的平均（标准差）敏感度和特异度分别为72.1%（7.3%）和99.2%（0.8%）。根据大小，检测小、中、大IOFB的敏感度分别为46%、76%和93%。根据位置，眼眶下外侧象限的敏感度最低（53%），而上内侧象限的敏感度最高（88%）。
本研究使用CR得出的结果支持了先前的结论，即传统X线在所有情况下都无法检测到金属性IOFB。诊断性能受IOFB大小和位置的影响。
