Question

Which combination of exposure factors will most likely contribute to producing the longest-scale contrast?

1. 10 mAS, 70kVp, 400 Film- Screen, 5:1 Grid, 14 x 17 inches Field Size
2. 12 mAS, 90kVp, 200 Film- Screen, 8:1 Grid, 14 x 17 inches Field Size
3. 15 mAS, 90kVp, 200 Film- Screen, 12:1 Grid, 8 x 10 inches Field Size
4. 20 mAS, 80kVp, 400 Film- Screen, 10:1 Grid, 11 x 14 inches Field Size
Answer:
2 mAS, 90kVp, 200 Film- Screen, 8:1 Grid, 14 x 17 inches Field Size

Answer 1

The combination producing the longest-scale contrast is option 1 with 10 mAs, 70 kVp, and a 5:1 grid, leading to greater differences in attenuation and thus higher contrast.

Step-by-step explanation:

The combination of exposure factors that will most likely contribute to producing the longest-scale contrast is the option with the lowest kVp and the highest grid ratio, which is '10 mAs, 70 kVp, 400 Film-Screen, 5:1 Grid, 14 x 17 inches Field Size'. Lower kVp settings yield higher contrast in the resulting image, as they result in greater differences in attenuation between different tissues. Similarly, a higher grid ratio removes more scattered radiation, which can degrade image contrast. Therefore, in these given options, setting (1) is the most likely to produce the longest-scale contrast.