Classics in abdominal radiology: the jumping deer sign.

The "jumping deer sign" is an ultrasonographic pattern that aids in identifying normal liver anatomy and distinguishing it from pathology. It includes the portal vein (deer's head and body), the gallbladder or cystic duct (tail), and the inferior vena cava (obstacle). This sign helps differentiate portal veins from intrahepatic ducts, crucial for diagnosing conditions like portal hypertension. It also assists in identifying gallbladder pathologies and assessing the IVC for hydration status. The jumping deer sign provides a clear reference for clinicians, improving diagnostic accuracy, especially for those with limited ultrasound experience.