Radiological features of non-accidental skeletal injury

Imaging plays a significant role in confirming the extent of non-accidental skeletal injury (NASI) and excluding any predisposing cause. Most NASI occurs in the pre-mobile child, where a clear history of injury is not always evident. In the older child the history is crucial to differentiating accidental from inflicted injury.When one injury is found, a skeletal survey is usually performed that may reveal other bony injuries or an underlying bone disorder. Whether the presenting injury is skeletal or not, a skeletal survey is important to detect occult injury in an infant presenting with symptoms of non-accidental injury. This should be performed to the agreed standard and checked by a radiologist for adequacy. The local radiologist should offer an opinion and refer onwards for a specialist opinion if they lack experience in paediatric trauma imaging. Supplemental or follow-up radiographs may confirm a diagnosis of non-accidental injury and assist in dating fractures.Clear communication by the radiologist is important for management, and forensic assessment re-timing, anticipated mechanism and symptoms of injury for the fractures identified. This involves multidisciplinary clinco-radiological correlation.Common presentation of NASI includes a fracture that is either unlikely from the child’s developmental level, or an explanation for an injury that alters between seeing the general practitioner, Accident and Emergency department and paediatrician. A careful family history and clinical examination are needed to identify any predisposing disorder, supplemented by imaging and appropriate laboratory investigations.Multidisciplinary working is essential to enable paediatricians, radiologists, child protection services and the police to assist the court to determine the true cause of injury.