Liver trauma diagnosis with contrast-enhanced ultrasound: interobserver variability between radiologist and emergency physician in an animal study. 
The purpose of our study was to evaluate interobserver variability between the radiologist and emergency physician in detecting blunt liver trauma by conventional and contrast-enhanced ultrasound (US) (CEUS).  We created 20 sites of blunt liver trauma in rabbits and performed conventional US and CEUS on the animals.  A radiologist and an emergency physician independently evaluated the degree of liver trauma.  Using contrast-enhanced computed tomography as a reference standard, the diagnostic performance of US and CEUS was calculated.  Interobserver variability between radiologist and emergency physician was compared before and after contrast enhancement of US.  Overall sensitivity and specificity for detecting liver trauma on conventional US, regardless of the degree of trauma, were 61.1% and 100% for the radiologist and 50% and 100% for the emergency physician.  On CEUS, the sensitivity and specificity were 94.4% and 100% for both the radiologist and emergency physician.  The interobserver agreement between emergency physician and radiologist increased from 0.867 to 0.955 after contrast enhancement on US.  Contrast-enhanced US may permit a more accurate diagnosis for liver trauma than conventional US by both the radiologist and emergency physician.  Contrast-enhanced US may also reduce interobserver variability for this diagnosis.