What does negative contrast show on a radiograph?

Negative contrast on a radiograph refers to the use of substances that do not absorb X-rays well, such as air or gas. When these substances are introduced into the area being imaged, they create areas that appear darker on the film. This occurs because the X-rays easily pass through the negative contrast medium, resulting in fewer X-rays being absorbed in those regions, and as a consequence, they show up as black zones on the radiograph. This allows for the differentiation and visualization of structures surrounding the area of interest, enhancing the diagnostic capabilities of the imaging procedure.

In the context of radiographs, understanding the effects of negative contrast is important for interpreting images accurately and recognizing how various materials interact with X-rays.