Nucpaedia
Nucpaedia
Short read · GI & hepatobiliary

Morphine-Augmented Cholescintigraphy

GI & hepatobiliary · 3 min read

When the gallbladder has not filled at 60 minutes: indications, timing, pitfalls and the rim sign

Gallbladder filling on cholescintigraphy excludes acute cholecystitis with a high degree of certainty. The problem is the gallbladder that has not filled by 60 minutes. You can wait 3–4 hours, or give a small dose of morphine and have the answer in 30 minutes, with fewer false positives.

How and when to give it

  • Morphine constricts the sphincter of Oddi and raises common bile duct pressure. If the cystic duct is patent, bile is pushed into the gallbladder.
  • Give it only when the gallbladder is not seen at 60 minutes and tracer is already in the small bowel.
  • Dose: 0.04 mg/kg, or a standard 2 mg, intravenously over 2–3 minutes. Keep imaging for 30–60 minutes.
  • Persistent non-filling 30 minutes after morphine means cystic duct obstruction. It carries the same weight as non-filling on 3–4 hour delayed images.
  • Absolute contraindications: respiratory depression in a non-ventilated patient, morphine allergy, raised intracranial pressure in a child. Acute pancreatitis is relative.

How well it works

  • Cholescintigraphy is the most accurate test for acute cholecystitis: pooled sensitivity 96% and specificity 90%, against 81% and 83% for ultrasound (57 studies).
  • In 91 patients with non-filling at 1 hour, delayed imaging gave 19 false positives among 46; morphine gave 4 among 45.
  • In an early comparison, morphine raised specificity from 83% to 100% with sensitivity unchanged at 96%.
  • In 163 hospitalised patients, many critically ill, morphine cholescintigraphy had a sensitivity of 99% and a specificity of 91%.

Preparation pitfalls: fasting, CCK and opioids

  • Too little fasting. Adults should fast at least 2 hours, preferably 6. A recent meal contracts the gallbladder and it will not fill.
  • Too much fasting. Fasting over 24 hours, especially on parenteral nutrition, also stops filling. Pre-treat with sincalide 0.02 µg/kg infused over 30–60 minutes, 15–30 minutes before the tracer.
  • Opioids already on board. Delay the study by 4 half-lives of the drug.
  • Other false positives: severe hepatocellular disease, high-grade bile duct obstruction, severe intercurrent illness, pancreatitis, severe chronic cholecystitis. With a biliary stent the gallbladder failed to fill in 21 of 22 patients, so morphine is futile.
  • False negatives: acalculous cholecystitis, the dilated cystic duct sign, and bowel or renal activity mimicking the gallbladder.

The rim sign

  • A band of increased hepatic activity along the gallbladder fossa. It is a sign of severe, late-stage acute cholecystitis.
  • In one series, 12 of 26 patients with gangrenous cholecystitis had a rim sign. In another, a marked rim occurred only in complicated disease, such as gangrene, perforation or empyema.
  • In a third, non-filling with a rim at 1 hour had a positive predictive value of 72%. Non-filling after morphine raised it to 86%.
Pearl

A rim sign raises suspicion but does not replace morphine. In that series, 7 of 43 patients with a rim at 1 hour filled after morphine and did not have acute cholecystitis.

Take home
  • Give morphine at 60 minutes only if the gallbladder is absent and tracer has reached the bowel; non-filling 30 minutes later means acute cholecystitis.
  • Most false positives are preventable: check fasting time, give sincalide after prolonged fasting or parenteral nutrition, and ask about opioids and biliary stents.
  • A rim sign points to severe or complicated disease, but still give morphine before calling the study.
Sources
  1. Tulchinsky M, Ciak BW, Delbeke D, et al. SNM practice guideline for hepatobiliary scintigraphy 4.0. J Nucl Med Technol. 2010;38(4):210-8.
  2. Kiewiet JJ, Leeuwenburgh MM, Bipat S, et al. A systematic review and meta-analysis of diagnostic performance of imaging in acute cholecystitis. Radiology. 2012;264(3):708-20.
  3. Kim CK, Tse KK, Juweid M, et al. Cholescintigraphy in the diagnosis of acute cholecystitis: morphine augmentation is superior to delayed imaging. J Nucl Med. 1993;34(11):1866-70.
  4. Choy D, Shi EC, McLean RG, et al. Cholescintigraphy in acute cholecystitis: use of intravenous morphine. Radiology. 1984;151(1):203-7.
  5. Flancbaum L, Choban PS, Sinha R, Jonasson O. Morphine cholescintigraphy in the evaluation of hospitalized patients with suspected acute cholecystitis. Ann Surg. 1994;220(1):25-31.
  6. Flancbaum L, Alden SM. Morphine cholescintigraphy. Surg Gynecol Obstet. 1990;171(3):227-32.
  7. Shim H, Aikins A, Hyun H, et al. Negative impact of indwelling biliary stent on gallbladder visualization on cholescintigraphy. Clin Nucl Med. 2015;40(11):856-8.
  8. Colletti PM, Cirimelli KM, Radin DR, et al. Radionuclide angiography in suspected acute cholecystitis: further observations. Clin Nucl Med. 1989;14(12):867-73.
  9. Bohdiewicz PJ. The diagnostic value of grading hyperperfusion and the rim sign in cholescintigraphy. Clin Nucl Med. 1993;18(10):867-71.
  10. Oates E, Selland DL, Chin CT, Achong DM. Gallbladder nonvisualization with pericholecystic rim sign: morphine-augmentation optimizes diagnosis of acute cholecystitis. J Nucl Med. 1996;37(2):267-9.
← BackShort reads

Spotted an error or something out of date? Report an error