Division of Radiology, Department of Medical Technology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Department of Oral and Maxillofacial Radiology, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
Department of Radiological Technology, Faculty of Health Sciences, Kobe Tokiwa University, 2-6-2 Otanicho, Nagata-ku, Kobe 653-0838, Japan.
Phys Med. 2022 Mar;95:176-181. doi: 10.1016/j.ejmp.2022.02.004. Epub 2022 Feb 23.
Recently developed and commercialized dual-layer flat panel detectors (DL-FPDs) with two indirect scintillators are capable of acquiring dual-energy X-ray images. However, in clinical practice, they are utilized to perform conventional radiography using diagnostic X-rays with a wide energy spectrum. The two layers of the DL-FPD may affect the obtained image quality, even when only using one layer for conventional image acquisition, and these effects are yet to be substantiated. Therefore, in this study, we quantitatively evaluated the image quality of a conventional chest radiography using DL-FPD and visually verified the characteristics of the chest anthropomorphic phantom images.
The physical characteristics of the system were evaluated using the pre-sampled modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE), for beam quality RQA 7 and RQA 9. In addition, the subjective visibility of the anthropomorphic chest phantom and simple objects images were compared with those of a conventional single-layer flat-panel detector (SL-FPD).
No significant differences were found in the MTF between the SL-FPD and DL-FPD images. In addition, a higher DQE was observed at some exposure doses and in the high spatial frequency regions wherein NNPSs were lower for DL-FPD than for SL-FPD. Furthermore, no significant differences were found in the subjective visibility of the chest phantoms in each system.
We concluded that the image quality of the conventional radiography acquired with DL-FPD is comparable to or better than that of the SL-FPD.
最近开发并商业化的双层平板探测器（DL-FPD）具有两个间接闪烁体，能够获取双能 X 射线图像。然而，在临床实践中，它们被用于使用具有宽能谱的诊断 X 射线进行常规放射摄影。即使仅使用一层来获取常规图像，DL-FPD 的两层也可能会影响获得的图像质量，而这些影响尚未得到证实。因此，在本研究中，我们使用 DL-FPD 对常规胸部 X 射线摄影的图像质量进行了定量评估，并对胸部人体模型图像的特征进行了视觉验证。
使用预采样调制传递函数（MTF）、归一化噪声功率谱（NNPS）和探测量子效率（DQE）评估系统的物理特性，用于 RQA 7 和 RQA 9 射线质量。此外，比较了人体模型和简单物体图像在 DL-FPD 和常规单层平板探测器（SL-FPD）中的主观可见度。
在 MTF 方面，SL-FPD 和 DL-FPD 图像之间没有发现显著差异。此外，在某些曝光剂量和高空间频率区域，DL-FPD 的 DQE 高于 SL-FPD，而 NNPS 较低。此外，在每个系统中，胸部模型的主观可见度没有发现显著差异。
我们得出结论，DL-FPD 采集的常规放射摄影的图像质量与 SL-FPD 相当或更好。
