Table 2 Fluoroscopic image acquisition protocols of the Ta-specific contrast-to-noise ratio-driven exposure control

Spatial frequency (lp/mm)

1.4

Average velocity (mm/s)

15

Material of interest specific

tantalum

Image quality levels

0.4, 0.7, 0.9, 1.1, 1.3, 1.6, 1.8, 2.2, 2.5, 2.8, 3.2, 3.6, 4.0, 4.5, 5.0, 5.6, 6.3, 7.1, 9.0, 18.0

Image quality gradient

0.5

Maximum air kerma rate (mGy/min)

160

Minimum Cu filter (mm)

0.1

Maximum Cu filter (mm)

0.9

Frame rate (frames/s)

7.5

Reference water value (mm)

230