Radiograph exposure

Nurses are usually great at radiographic technique, with the flip side that vets are often poor… if you find rules of exposure confusing, then a simple tip is to think of it like toast: overcooked toast burns and goes black.

If your KV is set too high for the area being imaged, the film will be over exposed (dark) and demonstrate a flat, grey background. That is, of course, if you have not pushed it to far so as to black out (burn out) the image. If the KV is too low, the dense areas being imaged will not be penetrated. The film, or parts of it, will be white.

If the MAS is too high, the film will be over exposed (dark) demonstrating a black background. If the MAS is too low, the film will be white and washed out.

Lastly, if you change one factor (MAS or KV) you may need to change the other so as to balance the film density.

So:

• If your films are dark and grey reduce the KV.
• If your films are dark and black reduce the MAS.
• If your films are light with no bony outlines clearly seen, increase the KV.
• If your films are light but the bony outline is there, increase the MAS.