Non-visualization of the gallbladder on a HIDA scan is most consistent with which diagnosis?

Non-visualization of the gallbladder on a HIDA scan is most consistent with which diagnosis?

• A. Biliary Obstruction
• B. Cholecystitis
• C. Acute Pancreatitis
• D. Gallstone Ileus

Answer: (B)

The main idea is that a HIDA scan shows whether bile can reach and fill the gallbladder. After injection, the tracer is taken up by the liver and excreted into bile; if the cystic duct is open, the gallbladder will fill and be visualized. When the cystic duct is obstructed—most commonly by inflammation in acute cholecystitis—the tracer cannot enter the gallbladder, so the gallbladder is not seen on the scan. This pattern is the hallmark of cystic duct obstruction due to cholecystitis, making it the best fit for the scenario described. Other conditions listed do not typically cause non-visualization of the gallbladder on HIDA in the same way.

The main idea is that a HIDA scan shows whether bile can reach and fill the gallbladder. After injection, the tracer is taken up by the liver and excreted into bile; if the cystic duct is open, the gallbladder will fill and be visualized. When the cystic duct is obstructed—most commonly by inflammation in acute cholecystitis—the tracer cannot enter the gallbladder, so the gallbladder is not seen on the scan. This pattern is the hallmark of cystic duct obstruction due to cholecystitis, making it the best fit for the scenario described. Other conditions listed do not typically cause non-visualization of the gallbladder on HIDA in the same way.