HIDA Hepatobiliary Scintigraphy

Hepatobiliary scintigraphy (HIDA scan) uses a Tc-99m-labelled iminodiacetic acid analogue (mebrofenin or disofenin) that is extracted by hepatocytes and excreted into bile, allowing dynamic evaluation of hepatocyte function, bile flow and gallbladder filling. It is the most specific imaging test for acute cholecystitis (non-visualisation of the gallbladder from cystic-duct obstruction), and with sincalide (CCK) provocation it quantifies gallbladder ejection fraction for suspected chronic acalculous cholecystitis and biliary dyskinesia. It also detects bile leaks and evaluates biliary atresia in neonates.

Indications

Suspected acute cholecystitis when ultrasound is equivocal
Suspected chronic acalculous cholecystitis / biliary dyskinesia — gallbladder ejection fraction with CCK
Detection and localisation of post-operative or post-traumatic bile leak
Assessment of biliary-enteric anastomosis patency and biliary obstruction
Differentiation of neonatal biliary atresia from neonatal hepatitis (with phenobarbital priming)

Contraindications & Cautions

Pregnancy is a relative contraindication; justify and minimise dose
Breastfeeding: interruption is generally not required for Tc-99m mebrofenin, though local guidance may advise brief interruption for free pertechnetate
Sincalide (CCK) is contraindicated in the presence of gallstones at risk of impaction and in pregnancy
Morphine augmentation is contraindicated in suspected complete biliary obstruction, morphine allergy and acute pancreatitis
Very high serum bilirubin (>~5-10 mg/dL) reduces hepatic extraction and biliary excretion, degrading study quality (mebrofenin tolerates higher bilirubin than older agents)

Patient Preparation

Fast for 4-6 hours to allow gallbladder filling (a full, recently stimulated gallbladder may not fill and mimic obstruction)
Avoid a fast longer than ~24 hours or ensure sincalide pre-treatment to empty a stagnant, bile-filled gallbladder
Withhold opioids for ~6 hours before the study as they contract the sphincter of Oddi and delay bowel transit
For gallbladder ejection fraction, infuse sincalide (0.02 mcg/kg over 60 minutes) to avoid falsely low values from rapid infusion
Confirm pregnancy status and recent oral contrast or opioid administration

Technique & Parameters

Inject Tc-99m mebrofenin (or disofenin) 185-370 MBq intravenously
Acquire dynamic anterior images over the right upper quadrant for ~60 minutes (1 frame/min)
If the gallbladder is not seen by 60 minutes, give morphine 0.04 mg/kg IV to contract the sphincter and promote filling, then image a further 30 minutes; alternatively acquire delayed images to 3-4 hours
For ejection fraction, infuse sincalide over 30-60 minutes and record pre- and post-stimulation gallbladder counts
Add SPECT/CT or delayed lateral/oblique views to localise bile leaks or ectopic accumulation

Systematic Review

Confirm prompt hepatic extraction and blood-pool clearance (hepatocyte function)
Track biliary excretion into intrahepatic ducts, common duct, gallbladder and bowel and note the timing of each
Assess gallbladder visualisation by 60 minutes and after morphine or on delayed images
Calculate gallbladder ejection fraction from pre- and post-sincalide counts
Search for tracer outside the biliary tree (subhepatic, paracolic, peritoneal) indicating a leak

Key Findings & Significance

Non-visualisation of the gallbladder by 60 minutes and after morphine (or by 3-4 h delayed) indicates cystic-duct obstruction / acute cholecystitis
Gallbladder ejection fraction below ~35-38% after CCK/sincalide is abnormal and supports chronic acalculous cholecystitis / biliary dyskinesia
Pericholecystic hepatic "rim sign" (increased uptake adjacent to the gallbladder fossa) suggests complicated/gangrenous cholecystitis
Tracer accumulating outside the ducts and gallbladder confirms a bile leak
Absent bowel activity at 24 hours with good hepatic uptake in a neonate suggests biliary atresia

Differential Considerations

Gallbladder non-visualisation: acute cholecystitis, chronic cholecystitis, prolonged fasting, recent meal, prior cholecystectomy
Delayed bowel transit: biliary obstruction, sphincter of Oddi dysfunction, opioid effect
Low ejection fraction: chronic acalculous cholecystitis, biliary dyskinesia, medication effect (opioids, calcium-channel blockers)
Extrabiliary activity: bile leak, duodenogastric reflux, free pertechnetate in stomach, urinary/renal excretion
Neonatal absent bowel activity: biliary atresia versus severe neonatal hepatitis

Pearls & Pitfalls

Non-visualisation is highly specific for acute cholecystitis; delayed visualisation (1-4 h) suggests chronic cholecystitis
Both over-fasting (>24 h) and recent eating cause false non-visualisation — control fasting time and consider sincalide pre-treatment
Infuse sincalide slowly (over 30-60 min); rapid infusion causes gallbladder spasm and a falsely low ejection fraction
The rim sign raises concern for gangrenous cholecystitis and warrants urgent surgical correlation
Morphine augmentation shortens the study by promoting gallbladder filling but must be avoided in complete obstruction

Structured Report

State tracer, activity, fasting time, and any morphine or sincalide intervention
Report hepatic extraction, biliary-to-bowel transit times and gallbladder visualisation timing
Give the gallbladder ejection fraction with the reference threshold when performed
Describe and localise any bile leak on delayed or SPECT/CT images
Provide a clear conclusion addressing acute versus chronic cholecystitis, dyskinesia, leak or obstruction

References

Tulchinsky M, et al. SNMMI Practice Guideline for Hepatobiliary Scintigraphy 4.0. J Nucl Med Technol 2010
EANM procedure guidelines for hepatobiliary scintigraphy
Ziessman HA. Hepatobiliary scintigraphy in 2014. J Nucl Med 2014
Tulchinsky M, et al. Radionuclide imaging of the hepatobiliary system. RadioGraphics

Educational clinical decision support only. Protocols vary by institution and equipment; always confirm with a qualified radiologist and local guidelines before clinical use.

HIDA Hepatobiliary Scintigraphy

📋 Indications

⛔ Contraindications & Cautions

🧑‍⚕️ Patient Preparation

⚙️ Technique & Parameters

🔎 Systematic Review

🩻 Key Findings & Significance

🧠 Differential Considerations

💡 Pearls & Pitfalls

📝 Structured Report

📚 References