What is the normal biodistribution of Tc mebrofenin?

• A. Liver, spleen, intestines
• B. Liver, gallbladder, bowel
• C. Liver, kidneys, bladder
• D. Liver, heart, lungs

Answer: (B)

The normal biodistribution of Tc mebrofenin primarily includes the liver, gallbladder, and bowel due to its function as a hepatobiliary imaging agent. Mebrofenin is designed to mimic the behavior of bilirubin, which is naturally taken up by hepatocytes (liver cells), excreted into bile, and subsequently delivered to the gallbladder for storage. After being stored in the gallbladder, mebrofenin can flow into the intestines during digestion, thus highlighting these organs during imaging procedures.

This characteristic distribution helps in evaluating the function of the liver and biliary system, making it essential for diagnosing conditions related to these areas, such as cholestasis or obstructive jaundice. Other organ systems such as the kidneys or heart do not typically show significant uptake of Tc mebrofenin, as its primary pathway is biliary rather than renal or cardiac. Understanding this specific biodistribution is crucial for interpreting the results of scans using Tc mebrofenin effectively.