From the Guidelines
An abnormal Ejection Fraction (EF) on a Hepatobiliary Iminodiacetic Acid (HIDA) scan, in the absence of other laboratory or imaging findings, is indicative of gallbladder dysfunction and may be supportive of a diagnosis of functional gallbladder disorder (FGBD) 1.
Clinical Significance
The finding of an abnormal EF is not specific for FGBD and may occur in patients with various medical conditions, such as diabetes, celiac disease, or irritable bowel syndrome, as well as in patients taking certain medications like opioid analgesics, calcium channel blockers, or oral contraceptive agents 1.
Diagnostic Considerations
In patients with suspected biliary pain and an anatomically normal appearing gallbladder, a HIDA scan with measurement of a gallbladder ejection fraction (GBEF) can be a useful diagnostic tool, providing a physiologic, noninvasive, and accurate quantitative assessment of gallbladder contraction 1.
Key Points to Consider
- An abnormal GBEF has been reported to be indicative of gallbladder dysfunction and supportive of a diagnosis of FGBD 1.
- The gallbladder may not be responsible for a decreased GBEF, and outflow obstruction from abnormalities of the cystic duct or sphincter of Oddi may be responsible 1.
- Patients with suspected functional biliary pain and an intact gallbladder without evidence of gallstones on transabdominal ultrasonography should be carefully evaluated to exclude other causes for their symptoms 1.
Treatment Implications
Treatment for patients with consistent symptoms and documented low EF on HIDA scan may involve cholecystectomy, with many experiencing symptom resolution despite the absence of other objective findings. However, it is crucial to approach each case with caution, considering the potential for false positives and the need for a comprehensive evaluation to rule out other causes of symptoms 1.
From the Research
Significance of Abnormal Ejection Fraction in HIDA Scan
- An abnormal Ejection Fraction (EF) in a Hepatobiliary Iminodiacetic Acid (HIDA) scan is significant in diagnosing biliary dyskinesia and predicting improvement after cholecystectomy 2.
- A low EF (<50%) is associated with a high rate of improvement or resolution of symptoms after cholecystectomy, with a 94.5% improvement rate in one study 2.
- However, the utility of HIDA scan with EF in patients with typical symptoms of biliary colic and negative ultrasounds is limited, and it should not be used to make a decision for cholecystectomy in these cases 3.
Predictive Value of HIDA Scan with EF
- The predictive value of HIDA scan with EF is marginal, with a sensitivity of 49% and specificity of 38% in predicting sphincter of Oddi hypertension (SOH) 4.
- The positive predictive value (PPV) of abnormal HIDA EF is high, but it is not much better than the clinical impression, and the negative predictive value (NPV) is poor 4.
- In patients with atypical symptoms, a HIDA scan with EF can be helpful in predicting symptom improvement, with a resolution rate of 64% in patients with positive HIDA and 43% in patients with negative HIDA 3.
Role of Cholecystectomy in Abnormal EF
- Cholecystectomy is the accepted treatment for low EF (less than 33%), and it can also be effective in patients with hyperkinetic gallbladder (EF ≥80%) 5.
- A study found a 95.9% symptom resolution rate among patients with hyperkinetic gallbladder who underwent minimally invasive cholecystectomy 5.
- In pediatric patients with normokinetic biliary dyskinesia (normal EF) and pain with CCK injection, laparoscopic cholecystectomy can result in resolution of symptoms for a majority of patients 6.