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Figure 3.3 These images illustrate the effect of too high exposures resulting in a ‘blackout artefact’. The
image on the left is a dorsoproximal-palmarodistal radiograph of the navicular bone, where too high exposures
have led to a ‘blackout’ artefact obscuring the lateral and medial edges of the navicular bone. The radiograph
on the right is a radiograph of the same foot with lower exposures that shows considerable enthesophyte
formation at the attachment of the sesamoidean collateral ligaments (white arrows).

Figure 3.4 This figure illustrates the effect of exposure on the signal-to-noise ratio in an image. These are
two dorsoproximal-palmarodistal radiographs of a foot; the image on the left was acquired with 60 kVp and
10 mAs whereas the image on the right was acquired with half the mAs. The image on the right shows more
noise that can be appreciated as a speckled pattern and obscures anatomical detail compared to the image
on the left where there is less noise and more detail.

Equine Radiography.indb 15 27/11/2018 11:04