From the Guidelines
A HIDA scan is the most sensitive and specific imaging modality for evaluating acute calculus cholecystitis (ACC), as well as the function of the gallbladder and bile ducts. This nuclear medicine imaging test uses a radioactive tracer that is injected into the bloodstream and taken up by liver cells, then excreted into the bile 1. The scan tracks the flow of bile from the liver through the bile ducts, into the gallbladder, and finally into the small intestine. It's particularly useful for diagnosing conditions like gallbladder inflammation (cholecystitis), bile duct obstruction, bile leaks after surgery, and abnormal gallbladder emptying (gallbladder dyskinesia). Some key points to consider when evaluating the use of a HIDA scan include:
- The diagnostic accuracy of computed tomography (CT) is poor for ACC, making HIDA scan a better choice 1
- Magnetic resonance imaging (MRI) is as accurate as abdominal US, but HIDA scan has the highest sensitivity and specificity 1
- The procedure typically takes 1-4 hours, requires fasting beforehand, and involves lying still under a gamma camera that detects the radioactive tracer
- The test is generally safe with minimal radiation exposure, though patients should inform their doctor if pregnant or breastfeeding
- During the test, patients may receive a medication called cholecystokinin (CCK) to stimulate gallbladder contraction, allowing assessment of gallbladder emptying efficiency.
From the Research
Hepatobiliary Iminodiacetic Acid (HIDA) Scan Evaluations
A HIDA scan evaluates the function and structure of the gallbladder and biliary system. The scan uses radioactive drugs and specialized cameras to make imaging diagnoses based on physiology 2.
- The most common indication for HIDA imaging is acute cholecystitis, diagnosed by nonfilling of the gallbladder due to cystic duct obstruction 2, 3.
- HIDA can detect high-grade biliary obstruction prior to ductal dilatation, and images reveal a persistent hepatogram without biliary clearance due to the high backpressure 2.
- HIDA also aids in the diagnosis of partial biliary obstruction due to stones, biliary stricture, and sphincter of Oddi obstruction 2, 4.
- The scan can confirm biliary leakage postcholecystectomy and hepatic transplantation 2.
- Calculation of a gallbladder ejection fraction after cholecystokinin infusion is commonly used to diagnose chronic acalculous gallbladder disease 2, 5.
- HIDA imaging is useful in assessing biliary drainage in jaundiced patients with surgically altered biliary tract anatomy 4.
- The scan can evaluate congenital gallbladder and biliary duct anomalies, and describe their imaging appearance on HIDA scan 6.