giovedì 18 dicembre 2008
Retinal hemorrhage in non accident trauma
Figure 1: T2*GRE axial image through the globe demonstrates nodular low signal in both retinas representing bloom artifacts from blood products suggesting retinal hemorrhage.
Figure 2: T2*GRE axial image shows low signal in the posterior parietal subdural space suggesting subdural hemorrhage.
Figure 3: Axial T1 image shows left frontal subdural fluid collection similar to CSF signal suggesting subdural hygroma.
Diagnosis: Retinal hemorrhage in non accident trauma
Child physical abuse is an unfortunately common occurrence that may manifest as any pattern of injury. Some patterns of injury (metaphyseal fractures, posterior rib fractures, subdural hemorrhages, retinal hemorrhages) are more suggestive and specific than others. Child abuse is often misdiagnosed and under-recognized by physicians and caregivers.
Non-accidental head injury (NAHI) or shaken baby syndrome (SBS), (some authors prefer the term shaken-impact syndrome), occurs in 12% of the physically abused children and is a major cause of neurological disability and death during infancy. Radiological imaging plays a crucial role in evaluating cranial injury, both for guiding medical management and the forensic aspects of abusive trauma. The neurologic injuries are more devastating than other injuries. NAHI is the leading cause of morbidity and mortality in abused children. MRI is the test of choice over CT for detecting different ages of intracranial hemorrhages, shearing injuries, and retinal hemorrhages.
Subdural hemorrhage is the most common intracranial lesion in shaken baby syndrome. Other findings are cerebral edema, subarachnoid hemorrhage, intraparenchymal hemorrhage, intraventricular hemorrhage, diffuse axonal injury, shearing injury, ischemia and brain herniation. Retinal hemorrhages may be found in 50%-100% of shaken infants, the prevalence of retinal hemorrhages in victims who die approaches 100%. Retinal hemorrhage is a characteristic and diagnostic feature of SBS. The severity of retinal hemorrhage is strongly correlated with intracranial injury in SBS. It is therefore very important to recognize retinal hemorrhage on neuroimaging.