A HIDA (hepatobiliary iminodiacetic acid) scan is an imaging procedure that provides insight into the function of your liver, bile ducts, and gallbladder. It primarily evaluates how well bile flows through this system. During the scan, a radioactive tracer is introduced into the body, which then travels with the bile, allowing specialists to visualize its movement and identify potential issues within the biliary tract. This test helps diagnose various conditions affecting these organs.
Understanding Normal HIDA Scan Results
A healthy HIDA scan shows a predictable progression of the radioactive tracer through your biliary system. The liver rapidly takes up the tracer, which then moves into the bile ducts. Within approximately 30 to 60 minutes, the tracer should fill the gallbladder. Subsequently, it passes from the gallbladder and bile ducts into the small intestine. If a medication like cholecystokinin (CCK) is administered to stimulate gallbladder contraction, a normal result includes an ejection fraction above 30% to 35%, indicating proper gallbladder emptying.
Visual Indicators of an Abnormal HIDA Scan
An abnormal HIDA scan shows distinct visual patterns indicating biliary problems. Non-visualization of the gallbladder, where the tracer does not enter, suggests a blockage preventing bile flow. Delayed visualization means the tracer appears in the gallbladder much later than expected, sometimes after 60 minutes. If the tracer does not pass into the small intestine, it indicates a common bile duct obstruction. Tracer presence outside the biliary system indicates a bile leak, while a low gallbladder ejection fraction (below 35%) suggests the gallbladder is not contracting effectively.
Common Conditions Revealed by Abnormal Scans
Abnormal HIDA scan findings often correspond to specific medical conditions. Non-visualization commonly suggests acute cholecystitis, an inflammation often caused by a cystic duct blockage. Delayed visualization can indicate chronic cholecystitis, a long-standing inflammation, or other chronic gallbladder issues. Failure of the tracer to reach the small intestine points to a common bile duct obstruction, often caused by gallstones. Tracer leakage outside the biliary system indicates a bile leak, which can occur after surgery or trauma; a low ejection fraction, where the gallbladder does not empty adequately, is associated with biliary dyskinesia or chronic cholecystitis.
Next Steps Following an Abnormal Scan
An abnormal HIDA scan result typically leads to further medical evaluation. Your healthcare provider will discuss the findings and their implications. Additional diagnostic tests, such as ultrasound, CT, or MRI, might be recommended to confirm the diagnosis or provide more detailed information. Based on the confirmed diagnosis, various treatment options are considered, ranging from medication and dietary adjustments for milder conditions to surgical intervention, such as gallbladder removal (cholecystectomy), for more severe issues like acute cholecystitis or symptomatic biliary dyskinesia. Adhering to your medical team’s advice is important for managing the condition and improving health.