Pearls and Pitfalls in Imaging of Abusive Head Trauma

Abusive head trauma (AHT) is the leading cause of fatal head injuries in infants. The mechanism of injury usually involves vigorous shaking of the infant, impact, or a combination of the 2. There are characteristic imaging findings of which the most common are subdural hemorrhages. Parenchymal injuries to the brain are common as well, including hypoxic ischemic injury, diffuse axonal injury, and cerebral contusions. Retinal hemorrhages are common with AHT and are best evaluated by fundoscopy, however, high grade retinal hemorrhages may be detected on cross-sectional imaging. Skull fractures are not specific to AHT but are present in third of the cases and tend to be complex in association with AHT. Injuries to the spine are more common than previously thought and typically involve soft tissues rather than bones, with the most common being ligamentous injuries in the craniocervical junction. In the setting of AHT, an affected infant would typically exhibit multiple findings. While CT of the head is the first modality of choice for assessment of an infant with AHT, magnetic resonance imaging examination of the brain and spine should follow due to its higher sensitivity for detection of these findings.