This report presents the fundamental temporospatial characteristics of a dynamic flat-panel detector (FPD) system. We
investigated the relationship between pixel value and X-ray pulse output, and examined reproducibility, dependence on
pulse width, tube voltage, and pulse rate. Sequential images were obtained using a direct conversion-type dynamic FPD.
The exposure conditions were: 110 kV, 80 mA, 6.3 ms, 7.5 fps,
source-to-image distance (SID) 1.5 m. X-ray pulse
output was measured using a dosimetry system with a sampling interval of 70 μs, to determine temporal changes in each
X-ray pulse output. Temporal changes in pixel value were measured in the obtained images, and the relationship
between pixel value and X-ray pulse output was examined. Reproducibility was assessed by comparing the results in two
sequential images obtained under the same exposure conditions. Moreover, the relationships and properties were
evaluated by changing the pulse width (12 ms and 25 ms), tube voltage (80 kV, 90 kV, and 100 kV), and pulse rate (3.75
fps and 15 fps). The results showed a good correlation between the
X-ray pulse output and pixel values. Fluctuation of
the pixel value measured in sequential images is thought to be mainly due to changes in X-ray pulse output, and is not
caused by FPD.