Brown P H, Silberberg P J, Thomas R D, Strife J L, Towbin R B
Department of Diagnostic Radiology, Oregon Health Science University, Doernbecher Children's Hospital, Portland 97201-3098, USA.
Pediatr Radiol. 2000 Apr;30(4):236-42. doi: 10.1007/s002470050729.
Traditionally, pediatric radiologists have been advocates of fluoroscopy systems that provide diagnostic images at the lowest possible radiation dose to the pediatric patient. Manufacturers of fluoroscopic equipment vary as to their claims of "low radiation" exposures.
To obtain comparative data on radiation exposure and image quality from four pediatric hospitals, across variants of fluoroscopic equipment (such as pulsed versus continuous fluoroscopy).
Images were acquired from phantoms that simulated the size of a 3-year-old child. Phantom results, both stationary and rotating dynamic, were evaluated for radiation exposure and for image resolution of high- and low-contrast objects.
Radiation exposure from the four fluoro units varied widely; the lowest-dose selectable fluoro mode produced exposures varying between 34 and 590 mrads/min among the four fluoro units, and the highest-dose selectable fluoro mode produced 540-2,230 mrads/min. The lowest radiation exposures were produced by pulsed fluoro units, and the very lowest radiation exposure was produced by a fluoroscope that had been especially optimized for pediatric imaging. There was only a small variation in image quality among the hospitals for visualization of stationary objects. A wide variability was noted for detection of objects on the moving phantom.
The variability in the number of detected objects was considerably smaller than the variability in radiation exposure. Pulsed fluoroscopy provides improved resolution for moving objects. Optimization of one hospital's fluoroscope especially for pediatric imaging produced the best ratio of image quality to radiation exposure.
传统上,儿科放射科医生一直提倡使用能以尽可能低的辐射剂量为儿科患者提供诊断图像的荧光透视系统。荧光透视设备制造商对其“低辐射”暴露的宣称各不相同。
从四家儿科医院获取关于不同型号荧光透视设备(如脉冲式与连续式荧光透视)的辐射暴露和图像质量的对比数据。
从模拟3岁儿童大小的体模获取图像。对体模的静态和旋转动态结果进行辐射暴露以及高对比度和低对比度物体图像分辨率的评估。
四个荧光透视单元的辐射暴露差异很大;四个荧光透视单元中,可选择的最低剂量荧光透视模式产生的暴露剂量在34至590毫拉德/分钟之间变化,而可选择的最高剂量荧光透视模式产生的暴露剂量为540 - 2230毫拉德/分钟。脉冲式荧光透视单元产生的辐射暴露最低,而经过特别优化用于儿科成像的荧光透视仪产生的辐射暴露最低。各医院在静态物体可视化方面的图像质量仅有微小差异。在动态体模上检测物体时发现差异很大。
检测到的物体数量的差异远小于辐射暴露的差异。脉冲式荧光透视为动态物体提供了更高的分辨率。一家医院对荧光透视仪进行特别优化以用于儿科成像,产生了图像质量与辐射暴露之间最佳的比例。