Department of Radiological Science and Research Institute of Health Science, Yonsei University, Wonju, 220-710, Korea,
Radiol Med. 2014 Apr;119(4):231-9. doi: 10.1007/s11547-013-0337-0. Epub 2013 Dec 12.
The purpose of this study was to investigate the effect of various technical parameters for dose optimization in pediatric chest radiological examinations by evaluating effective dose and effective detective quantum efficiency (eDQE).
For tube voltages ranging from 40 to 90 kV in 10 kV increments at the focus-to-detector distance (FDD) of 100, 110, 120, 150, 180 cm, the eDQE was evaluated at same effective dose.
The eDQE was considerably higher without the use of the grid on equivalent effective dose. This indicates that the reduction of scatter radiation did not compensate for the loss of absorbed effective photons in the grid. The eDQE increased with increasing FDD because of the greater effective modulation transfer function (eMTF) with lower focal spot blurring. However, most of the major hospitals in Korea employed a short FDD of 100 cm with the grid. The entrance surface air kerma values for the hospitals of this survey exceeded the Korean reference level of 100 μGy.
The different reference levels might be appropriate for the same examination conducted on children of different ages. Also, it is necessary to refine the technical parameters to perform pediatric chest examinations.
本研究旨在通过评估有效剂量和有效探测量子效率（eDQE）来探讨在儿科胸部放射检查中优化剂量的各种技术参数的效果。
在焦点-探测器距离（FDD）为 100、110、120、150、180 cm 时，将管电压从 40 kV 以 10 kV 的增量增加到 90 kV，在相同有效剂量下评估 eDQE。
在不使用格栅的情况下，等效有效剂量的 eDQE 明显更高。这表明散射线的减少并没有补偿格栅中吸收的有效光子的损失。随着 FDD 的增加，eDQE 增加，因为较低的焦点模糊导致更大的有效调制传递函数（eMTF）。然而，韩国的大多数主要医院都使用 100 cm 的短 FDD 和格栅。本调查中各医院的体表空气比释动能值超过了韩国 100 μGy 的参考水平。
对于不同年龄的儿童进行相同的检查，不同的参考水平可能是合适的。此外，有必要细化技术参数以进行儿科胸部检查。
