What is the primary cause of the herringbone effect on radiographic films?

The herringbone effect on radiographic films is primarily caused by film being placed backwards in the cassette during exposure. This effect appears as a pattern of lines or a grid-like appearance that can obscure the diagnostic quality of the radiograph.

When the film is positioned incorrectly, the emulsion side, which is sensitive to radiation, does not receive the intended exposure. Instead, the less-sensitive non-emulsion side is exposed to the radiation, leading to this distinct pattern that is recognizable as the herringbone effect.

In contrast, while factors such as improper exposure, high temperature processing, or inadequate agitation can affect the quality of a radiographic film, they do not specifically create the herringbone pattern. These factors may result in overexposure, underexposure, or developing issues but will not generate the specific line pattern characteristic of the herringbone effect seen when the film is reversed.