Fig. 3

Image quality assessment of dark-field and transmission images. Dot plot of image quality grading of dark-field and transmission radiographs for the left or right lung with median and interquartile range on a 6-point ordinal scale (1 = not diagnostic, 6 = excellent) of all nine dark-field and transmission chest x-rays and all readers. Median grading is 4 and 5 for dark-field and transmission radiographs, respectively. Asterisks indicate statistical significance difference of median image quality gradings for left/right lung between dark-field and transmission radiographs. Non-significant differences (p > 0.050) for comparisons between left and right lung for median image quality gradings for dark-field/transmission radiographs are denoted by “ns”