Sonographic appearance of hematoma in liver, spleen, and kidney: a clinical, pathologic, and animal study.

Following the observation of several cases of localized echogenic foci in abdominal parenchymal organs in patients with acute bleeding due to trauma, an experimental study was designed to define the sonographic appearance of fresh, nonhemolyzed blood. Ultrasound scanning performed before and after the injection of blood or air into the parenchyma of cadaveric organs (liver, spleen, and kidney) resulted in consistent ultrasonic patterns. Linear echogenic foci resulted from the injection of 0.5 to 2.0 ml of blood, rounded echogenic foci were seen with air or 3- to 10-ml injections of blood, and the injection of contrast material (into the liver only) caused poorly defined hypoechoic areas. To determine if the ultrasound appearance of the cadaveric organs could have been caused mainly by air, an in vivo experiment was performed in which computed tomograms of the liver of a dog that had been injected with autologous blood were obtained. It is concluded that CT confirmed the ultrasound findings, and that ultrasound is useful for the investigation of hematoma following blunt, and possibly penetrating, trauma.