Are subdural hygromas the result of abusive head trauma? CT and MR imaging represent important tools for the
diagnosis of abusive head trauma in living infants. In addition, in-depth understanding of the pathogenesis of subdural hygromas is
increasingly required by neuroradiologists, pediatricians, and forensic physicians. Therefore, the current knowledge on subdural
hygromas is summarized and forensic conclusions are drawn. The most important diagnostic pitfalls, benign enlargement of the
subarachnoid space, and chronic subdural hematoma, are discussed in detail. Illustrative cases from forensic practice are presented.
Literature analysis indicates that subdural hygromas can occur immediately or be delayed. If other infrequent reasons can be
excluded, the presence of subdural hygromas strongly suggests a posttraumatic state and should prompt the physician to search for
other signs of abuse. To differentiate subdural hygromas from other pathologies, additional MR imaging of the infant’s head is
indispensable after initial CT scan.