From the Guidelines
A Hepatobiliary Iminodiacetic Acid (HIDA) scan is the gold standard for diagnosing acute cholecystitis, with the highest sensitivity and specificity compared to other imaging modalities such as CT and US 1.
Key Characteristics of HIDA Scan
- It has a higher sensitivity than US and CT, with values of 84.2%, 67.3%, and 59.8% respectively 1
- It is considered the gold standard for diagnosing acute cholecystitis 1
- It requires a patient to fast for several hours before undergoing the scan 1
- It is less costly than MRI/MRCP 1
Clinical Considerations
- The use of HIDA scan is limited in clinical practice due to the required resources and time 1
- It is a reasonable option as a subsequent imaging study beyond CT if acute cholecystitis is suspected 1
- MRI/MRCP is an alternative option that provides a clearer picture of the surrounding structures and a faster time to result, but is more costly 1
From the Research
Definition and Purpose of HIDA Scan
- A Hepatobiliary Iminodiacetic Acid (HIDA) scan is a principal imaging modality for evaluating the gallbladder and biliary tree 2.
- It is used to assess the functional integrity of the hepatobiliary system, providing valuable information in both pre- and postoperative evaluation of patients with suspected or known hepatobiliary disease 3.
- The HIDA scan aids in the diagnosis of acute cholecystitis (AC) but has limitations, and its results can be predicted using a model based on the Tokyo Guidelines 2018 (TG18) and patient characteristics 4.
Clinical Indications and Applications
- HIDA scans are used to investigate patients with typical biliary pain but normal trans-abdominal ultrasound scans 5.
- They are useful in detecting early posttransplantation biliary complications, such as biliary leaks, obstruction, or cholestasis, after liver transplantation 6.
- The scans can also help identify patients with chronic cholecystitis, even if the gallbladder ejection fraction is normal 5.
Diagnostic Utility and Limitations
- The diagnostic utility of HIDA scans lies in their ability to provide functional information about the hepatobiliary system, complementing morphological imaging techniques like ultrasound, CT, and MRI 3.
- However, the scans have limitations, such as false positives and false negatives, and correlation with clinical status and other imaging modalities is essential to confirm detected abnormalities 6.
- The recreation of symptoms following cholecystokinin (CCK) provocation is superior to ejection fraction in predicting medium-term outcomes in patients with biliary dyskinesia 5.