Sabina Bhoil and Rohit Bhoil explain the significance of a finding from brain scans that indicates inversion of the normal relationship between grey and white matter

The reversal sign is an ominous finding seen on computed tomographic images of the brain as an inversion of the normal attenuation relationship between grey and white matter. This article describes the pathophysiology of the reversal sign, which indicates irreversible neural tissue damage, and includes a brief case study of a child who drowned and later developed this sign. The child died two hours after presenting to the emergency department. Emergency healthcare professionals should be aware of this sign, which is significant in terms of diagnosis, management and prognosis. Knowledge of the reversal sign will also help emergency nurses support relatives who are about to be notified about the possible long-term neurological deficits in, or death of, their loved one.