Color Doppler detection of acoustic streaming in a hematoma model.

Accurate differentiation between stagnant blood and soft tissue or clotted and unclotted blood has potential value in managing trauma patients with internal hemorrhage. Determination by regular ultrasound (US) imaging is sometimes difficult because the sonographic appearance of blood, clots and soft tissue may be similar. A hematoma model was developed to investigate the use of acoustic streaming for hematoma diagnosis in an in vivo environment. The results showed that a derated spatial peak temporal average (SPTA) intensity of 30 W/cm(2) was needed to generate color-Doppler-detectable streaming in stirred blood. The streaming velocity increased in proportion to the derated intensity. Streaming was also detected in stagnant blood, but at higher intensities. In clots, streaming was not detected even at high intensities. The streaming detection may be a valuable tool for improving the distinction between liquid blood and clots or soft tissue in hematoma diagnosis.