‘Spot the difference’: the importance of recognizing symmetrical trauma

The eye can play tricks on us and optical illusions are commonly used to illustrate the fact that the brain interprets perceived images according to what it ‘expects’ to see. When viewing trauma imaging, we tend to subconsciously use the body’s symmetry as a reference point and therefore symmetrical injuries can easily be overlooked, even when gross. In this article, we will illustrate this phenomenon with examples of imaging from trauma cases and suggest how recognition of typical patterns of injury in addition to knowledge of some common pitfalls in trauma radiology can help us avoid the misinterpretation of bilateral symmetrical abnormalities.