Kupffer cells are specialized macrophages that line the sinusoids, or small blood channels, within the liver. They are part of the body’s immune system and function to filter bacteria, old red blood cells, and other debris from the blood as it passes through the liver. In contrast-enhanced ultrasound, Kupffer cells are clinically significant because certain contrast agents are taken up by these cells during a late phase of imaging, called the post-vascular or Kupffer phase. Normal liver tissue containing Kupffer cells takes up the contrast and appears enhanced, while many malignant tumors lack Kupffer cells and appear as dark defects, helping to identify and characterize liver lesions.
Sonography Term