From the Guidelines
You should get a HIDA scan if you have high clinical suspicion for acute cholecystitis and initial ultrasound (US) results are equivocal, or if other diagnostic possibilities are being considered for right upper quadrant (RUQ) abdominal pain and a computed tomography (CT) scan is also inconclusive. This recommendation is based on the most recent and highest quality study, which suggests that a HIDA scan is a reasonable option for diagnosing acute cholecystitis, especially when other imaging modalities are unclear 1.
When considering a HIDA scan, it's essential to weigh the benefits and risks, particularly in certain patient populations. For example, in pregnant people, ultrasound (US) or magnetic resonance imaging (MRI) may be preferred as the initial diagnostic imaging modality due to the risks associated with radiation exposure 1.
Some key points to consider when deciding on a HIDA scan include:
- The patient's clinical presentation, including symptoms such as jaundice, fever, and RUQ abdominal pain
- The results of initial imaging tests, such as ultrasound (US) or computed tomography (CT)
- The potential risks and benefits of the HIDA scan, including radiation exposure and the need for fasting beforehand
- Alternative diagnostic options, such as MRI or MRCP, which may provide additional information but are more costly and may not be as readily available 1.
In terms of the procedure itself, a HIDA scan typically involves injecting a radioactive tracer that follows the path of bile through the liver, gallbladder, and intestines, allowing doctors to assess the functioning of the biliary system. The procedure usually takes about 1-2 hours and requires fasting for 4-12 hours beforehand. While the radiation exposure is generally minimal and safe, it's crucial to carefully consider the risks and benefits, especially in vulnerable patient populations, such as pregnant women or children 1.
From the Research
Indications for a HIDA Scan
- Acute cholecystitis: diagnosed by nonfilling of the gallbladder due to cystic duct obstruction 2
- Biliary obstruction: HIDA can detect high grade biliary obstruction prior to ductal dilatation 2
- Partial biliary obstruction: due to stones, biliary stricture, and sphincter of Oddi obstruction 2
- Biliary leakage: postcholecystectomy and hepatic transplantation 2
- Chronic acalculous gallbladder disease: calculation of a gallbladder ejection fraction after cholecystokinin infusion is commonly used 2
- Congenital gallbladder and biliary duct anomalies: HIDA scan is one of the principal imaging modalities for evaluation 3
- Functional gallbladder disease: HIDA-CCK scan can assess function of the gallbladder and biliary tree 4
Clinical Scenarios where a HIDA Scan is Useful
- Acute abdomen: an absent gall bladder image with a normal hepatogram will strongly support the diagnosis of acute gall-bladder disease 5
- Jaundiced patients: HIDA imaging can diagnose hepatocellular disease, partial and complete obstruction 6
- Patients with intermittent right upper quadrant abdominal pain: HIDA-CCK scan can assess function of the gallbladder and biliary tree 4