What are the computed tomography patterns of head injury following low-velocity accidental head trauma in infants?

Differentiating accidental head trauma and abusive head trauma (AHT) may be challenging in infants.

To describe computed tomography (CT) scan findings following accidental low-velocity trauma in infants, focusing on features considered to be highly suggestive of AHT, such as rupture of bridging veins.

A single-center, retrospective study (2014-2022) was performed in infants aged 1 month to 12 months.

(i) any kind of minor head trauma leading to an Emergency Department visit (fall from a height of less than 2 m, direct head impact, low-velocity road accident (below 15 km/h); (ii) available clinical data and head CT scan.

Three hundred and six infants were included (mean age 5 months 14 days, 56.5% male). Fractures were observed in 89 patients (71 simple linear fractures). Intracranial hemorrhage was observed in 34 patients: simple post-traumatic focal extra-axial hemorrhage in 26 patients and more complex hemorrhage on CT and magnetic resonance imaging in eight patients, including three with evidence of bridging vein rupture. Among these cases, the child protection team expressed concern that two patients might have experienced AHT, while the third patient had a condylar fracture and it remains unclear whether the injury was the result of AHT or an accidental fall. A significant link was found between intracranial hemorrhage and fractures (P-value < 0.001), scalp swelling (P-value < 0.001), or clots located at the vertex (P-value < 0.001) and between fractures and scalp swelling (P-value < 0.001), the trauma mechanism (P-value < 0.001), neurological symptoms (P-value = 0.03), and intracranial hemorrhage (P-value < 0.001).

The main CT scan features following minor accidental trauma in infants are simple skull fractures and scalp swelling. Diffuse hemorrhage with rupture of bridging veins is exceptional in this context.