From the Guidelines
HIDA scan should be considered as a subsequent imaging test for diagnosing acute cholecystitis in non-pregnant adults when both US and CT are equivocal/nondiagnostic and clinical suspicion persists, as suggested by the 2024 clinical practice guideline update by the Infectious Diseases Society of America 1.
Diagnosis of Acute Cholecystitis
The diagnosis of acute cholecystitis can be challenging, and imaging tests play a crucial role in confirming the diagnosis. The 2020 World Society of Emergency Surgery updated guidelines for the diagnosis and treatment of acute calculus cholecystitis suggest that HIDA scan has a higher sensitivity compared to US and CT, with respective values of 84.2%, 67.3%, and 59.8% (p = 0.017) 1. However, the utilization of HIDA scan in clinical practice is limited due to the required resources and time.
Imaging Tests for Acute Cholecystitis
The choice of imaging test for acute cholecystitis depends on various factors, including the patient's clinical presentation, availability of resources, and the radiologist's expertise. A cross-sectional study evaluated the incremental benefits of cystic duct enhancement detected by CT for the diagnosis of cholecystitis in patients without visibly impacted gallstones, and found that the accuracy and sensitivity of the diagnosis increased significantly when considering cystic duct enhancement 1.
Recommendation
In clinical practice, a HIDA scan can be a useful diagnostic tool for acute cholecystitis, particularly when other imaging tests are inconclusive, as recommended by the 2024 clinical practice guideline update by the Infectious Diseases Society of America 1. Some key points to consider when using HIDA scan include:
- The test typically takes 1-4 hours and requires fasting for 4-6 hours beforehand
- The radiation exposure is minimal and considered safe for most patients
- The procedure itself is painless, but minor discomfort may occur from lying still or from the IV insertion
- The radioactive tracer will naturally leave the body within a day, and normal activities can be resumed immediately after the test.
From the Research
HIDA Scan Overview
- A HIDA scan is a type of imaging test used to assess the function and structure of the gallbladder and bile ducts 2, 3, 4, 5, 6.
- The scan uses a small amount of radioactive material to visualize the gallbladder and bile ducts.
Diagnostic Accuracy
- The sensitivity of HIDA scans for diagnosing acute cholecystitis is high, ranging from 87% to 91.7% 3, 4.
- The specificity of HIDA scans for diagnosing acute cholecystitis is also high, ranging from 79% to 95.5% 3, 4.
- HIDA scans are more accurate than ultrasound in diagnosing acute cholecystitis, especially in patients with a high risk of the disease 4.
Clinical Implications
- HIDA scans can help identify patients who are likely to benefit from surgical intervention, such as cholecystectomy 6.
- Patients with a positive HIDA scan result and no gallstones are more likely to experience symptom relief after cholecystectomy than those treated medically 6.
- The use of HIDA scans can help reduce the time to surgery and length of stay in patients with acute cholecystitis 4.