Background

Although x-ray dark-field imaging has been intensively investigated for lung imaging in different animal models, there is very limited data about imaging features in the human lungs. Therefore, in this work, a reader study on nine post-mortem human chest x-ray dark-field radiographs was performed to evaluate dark-field signal strength in the lungs, intraobserver and interobserver agreement, and image quality and to correlate with findings of conventional x-ray and CT.

Methods

In this prospective work, chest x-ray dark-field radiography with a tube voltage of 70 kVp was performed post-mortem on nine humans (3 females, 6 males, age range 52–88 years). Visual quantification of dark-field and transmission signals in the lungs was performed by three radiologists. Results were compared to findings on conventional x-rays and 256-slice computed tomography. Image quality was evaluated. For ordinal data, median, range, and dot plots with medians and 95% confidence intervals are presented; intraobserver and interobserver agreement were determined using weighted Cohen κ.

Results

Dark-field signal grading showed significant differences between upper and middle (p = 0.004–0.016, readers 1–3) as well as upper and lower zones (p = 0.004–0.016, readers 1–2). Median transmission grading was indifferent between all lung regions. Intraobserver and interobserver agreements were substantial to almost perfect for grading of both dark-field (κ = 0.793–0.971 and κ = 0.828–0.893) and transmission images (κ = 0.790–0.918 and κ = 0.700–0.772). Pulmonary infiltrates correlated with areas of reduced dark-field signal. Image quality was rated good for dark-field images.

Conclusions

Chest x-ray dark-field images provide information of the lungs complementary to conventional x-ray and allow reliable visual quantification of dark-field signal strength.

中文翻译：

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验尸X射线暗场胸部X光片的成像特征以及与常规X射线和CT的相关性。

背景

尽管已经针对不同动物模型中的肺部成像对X射线暗场成像进行了深入研究，但是关于人肺部成像特征的数据非常有限。因此，在这项工作中，对9个验尸后的人体胸部X射线暗场X射线照片进行了读者研究，以评估肺部的暗场信号强度，观察者之间和观察者之间的一致性以及图像质量，并将其与传统的X射线和CT。

方法

在这项前瞻性工作中，对9名人类（3名女性，6名男性，年龄范围52-88岁）进行了尸体解剖，其管电压为70 kVp的胸部X射线暗场射线照相。由三位放射科医生对肺中的暗场和透射信号进行了可视化量化。将结果与常规X射线和256层计算机断层扫描的结果进行比较。评估图像质量。对于序数数据，显示了具有中位数和95％置信区间的中位数，范围和点图；观察者内和观察者协议采用加权科恩决定κ。

结果

暗场信号进行分级表明上部和中部之间（显著差异p  = 0.004-0.016，读者1-3）上部和下部区域（以及p  = 0.004-0.016，读者1-2）。在所有肺区域之间，中位传输等级无差异。观察者内部和观察者之间的协议对于暗场（κ  = 0.793–0.971和κ  = 0.828–0.893）和透射图像（κ  = 0.790–0.918和κ  = 0.700–0.772）的分级是基本至几乎完美的。肺浸润与暗场信号减少的区域相关。对于暗场图像，图像质量被评为良好。

结论

胸部X射线暗场图像可提供与常规X射线互补的肺部信息，并可以对暗场信号强度进行可靠的视觉量化。