The importance of neuroimaging in abusive head trauma

• A shaking event is a common mechanism in abusive head trauma (AHT). • AHT is associated with greater morbidity and mortality than accidental (usually impact) head trauma. • AHT gives rise to different patterns of subdural haemorrhage (SDH) and parenchymal brain injury from impact head trauma. • Multifocal SDH is best regarded as a marker of a mechanism of injury but does not itself cause symptoms and signs. • Associated parenchymal brain injury leads to symptoms and signs and relates to outcome. • Published standards for the radiological investigation of AHT are available and should be followed. Abusive head trauma (AHT) is best defined as a head injury occurring to a child as a result of an act by a carer that may be negligent, reckless or deliberate. Whilst there are a number of different potential mechanisms involved in AHT, one of the most common is generally (although not universally) accepted to involve shaking; this article will concentrate on this type of injury and will therefore include AHT that refers to shaking injuries. Over the past decade, we have gained a much better understanding of the nature of such injuries from disciplines such as paediatrics, neuroradiology and neuropathology, and we are now better equipped to recognize such injuries and to intervene when an injury occurs towards the lower end of the spectrum of severity to try to prevent a later potentially more serious injury. This is extremely important as the mortality and morbidity in terms of neurodevelopmental outcome of injuries involving shaking are considerably worse than equivalent accidental injuries (the vast majority of which are secondary to impact head trauma). Some of the concepts regarding AHT that were widely held 10–15 years ago have either been shown not to be true or are not sustainable on the basis of the current evidence base. This article will review the role of neuroimaging in the diagnosis of AHT in the light of the current recommendations for imaging in suspected AHT and will discuss the current state of mainstream opinion in the context of everyday clinical experience and the published evidence base.