Background: Conventional ultrasonography (US) shows markedly lower sensitivity in detecting parenchymal injury and active bleeding in abdominal organs. This study was designed to evaluate the utility of contrast-enhanced US (CEUS) in the diagnosis of blunt trauma and active hemorrhage of the liver in an animal model.
Methods: Sixteen blunt injuries and 40 lacerations with active hemorrhage were created in livers of 14 pigs using laparotomy. The lacerations were divided into two groups: group I, in which the velocity of the traumatized artery was >20 cm/s; and group II, in which the velocity of the traumatized artery was < or =20 cm/s. Twenty minutes after the blunt trauma and immediately after the laceration was created, conventional US and CEUS were performed to observe the sonographic characteristics of trauma.
Results: The sensitivity of CEUS in detecting blunt hepatic trauma (100%; 16 of 16) was significantly higher than that of conventional US (37.5%; 6 of 16) (p < 0.001) based on the histopathology gold standard. Active hemorrhage was clearly detected as hyperechoic enhanced linear or clumpy regions in all of the lacerations in group I (100%; 20 of 20) and in 65% (13 of 20) of the lacerations in group II on CEUS. Acoustic shadowing was observed posterior to the enhanced hemorrhagic site in 12 lacerations from group I and in five lacerations from group II.
Conclusion: In this animal model, CEUS was found to be useful in detecting blunt trauma and active hemorrhage in the liver, which might significantly improve the efficacy of US for the diagnosis of hepatic trauma.