Sonography of a hemorrhagic cerebral contusion.

A previously healthy 6-week-old boy was accidentally dropped on his head on a linoleum floor. He cried immediately, with no loss of consciousness, vomiting, seizure, or obvious neurologic abnormality , and fell asleep spontaneously within 10 min after the accident without his normal feeding . Physical examination by the pediatrician about 30 min later was normal except for a hematoma in the right parietal area. Skull radiographs demonstrated a right parietal fracture. A real-time sonogram through the anterior fontanelle and lateral skull , obtained within hours of the fall , showed no extracerebral hemorrhage or midline shift. However, an elliptical , heterogeneous hyperechoic area 18 mm in maximum dimension could be delineated from the surrounding parenchyma in the periphery of the left parietal cortex (fig. 1 A) . This abnormality was interpreted as a contrecoup hemorrhagic contusion. A computed tomographic (CT) scan confirmed this impression (fig . 1 B). The infant continued to develop normally, and a follow-up examination was performed at 9 months of age. Sonography was unsuccessful because of near closure of the anterior fontanelle and increased thickness of the lateral skull. A CT scan was normal.