Pediatric blunt abdominal trauma: periportal tracking at CT.

Periportal zones of decreased attenuation at computed tomography (CT) have been described in a variety of disorders. In the setting of blunt abdominal trauma, the zones have been attributed to dissection of blood along the portal tracts. Because of the observation of isolated periportal tracking (PPT) in children after blunt trauma, the authors retrospectively reviewed CT scans of the abdomen obtained in 114 children to determine the frequency of PPT, liver injury, and peritoneal fluid. PPT was present in 22% of patients (25 of 114); it was associated with liver injury in 10 and was the only liver abnormality in 15. Pathologic correlation was available in two patients: In one it revealed marked periportal lymphedema and in the other, PPT of blood. This study indicates that both hemorrhage and lymphatic edema may be represented as PPT in children after blunt abdominal injury.