Post on 25-Jun-2015
transcript
MEMBROFENIN SCINTIGRAPHY IN BILE
DISORDERS
Presenter: Dr. Ravishwar Narayan
INTRODUCTION
Hepatobiliary scintigraphy evaluates hepatocellular function and the biliary system by tracing the production and flow of bile from the formative phase in the liver, and its passage through the biliary system into the small intestine.
INDICATIONS
Neonatal hyperbilirubinemia (biliary atresia vs. neonatal hepatitis)
Enterogastric (duodenogastric) reflux assessment
Assessment of biliary enteric bypass for bile leakage (e.g., Kasai procedure)
Esophageal bile reflux after gastrectomyAcute cholecystitisChronic cholecystitis
RADIOPHARMACY
Radionuclide
99mTc t1/2: 6 hours
Energies: 140 keV
Radiopharmaceutical
◦IDA (Imino Diacetic Acid)◦DISIDA (2,6-diisopropylacetanilido-iminodiacetic
acid)◦BRIDA (2,4,6-trimethyl,5-bromoacetanilido-
iminodiacetic acid/ mebrofenin)
Biokinetic features of Tc-99m mebrofenin and Tc-99m disofenin
Albumin delivers the radiotracer to the space of Disse. Tc-99m HIDA is taken up by the hepatocyte and secreted into bile canaliculi in free form where it mixes with the hepatic bile and serves as an ideal in vivo tracer for imaging of the entire hepatobiliary tree
PATIENT PREPARATION
NPO for 4–6 hours (2 hours for infants)
no opiates for 4 to 8 hours prior to exam
Explain the procedure
EQUIPMENT & COMPUTER SETUP
Camera: Large field of view
Collimator: LEAP/ LEHR
Computer Set-up◦Static Images: 500,000–1 million counts◦Flow Studies: 2 sec/frame for 60 seconds, then
immediate blood pool image◦Dynamic Studies: 60 sec/frame for 60–90
minutes◦Delayed images may be needed till 24 hrs
Positioning:
◦patient supine ◦camera anterior ◦liver in upper left quadrant of field of view
PHARMACOLOGIC INTERVENTIONS
Cholecystokinin:◦If patient is NPO for many hours, GB becomes
inactive, may be full of bile or sludge and so may not visualize. CCK is used to contract gallbladder so that visualization of bowel may occur after refilling
◦0.02 µg/ kg body wt. slow IV ◦Contraindication: recent positive ultrasound
examination for gallstones.
Morphine Sulphate :
◦When acute cholecystitis is suspected and the gallbladder is not seen by 30–60 min, 0.04 mg/kg morphine sulfate may be administered slow I.V.
◦If the cystic duct is patent, flow of bile into the gallbladder will be facilitated by morphine-induced temporary spasm of the sphincter of Oddi
◦Imaging is continued for another 30–60 min after morphine administration.
◦Imaging after morphine injection distinguishes between acute [no visualization] and chronic [eventual visualization] cholecystitis.
◦Contraindications: increased intracranial pressure in children respiratory depression in non-ventilated patients allergic to morphine history of pancreatitis
Phenobarbital ◦5 mg/ kg/day in two equally divided doses, for
5–7 days prior to cholescintigraphy.
◦Phenobarbital stimulates bile production and increases the secretion of the radiotracer into bile, enabling better delineation of bile ducts and duodenum in infants with neonatal hepatitis, but not in those with congenital biliary atresia
INTERPRETATION
Normal Results
◦Visualization of liver 5–15 seconds after injection◦hepatic and common bile duct and gallbladder 5–
60 minutes.◦Intestinal activity within 10–60 minutes
◦Gallbladder filling implies a patent cystic duct and excludes acute cholecystitis with a high degree of certainty
Normal cholescintigraphy.
Bile leak
◦present when tracer is found in a location other than the liver, gallbladder, bile ducts, bowel, or urine
◦Causes: Post procedural: M.C.
◦cholecystectomy, liver transplant Trauma to right upper quadrant area
Biliary atresia
◦Non visualization of Extra hepatic biliary tree & failure of tracer to enter the gut
◦d/d: hepatocellular disease
Efficacy of cholescintigraphy, ultrasonography, and liver biopsy in the differential diagnosis of congenital biliary atresia from neonatal
hepatitis
Biliary tract evaluation
Bile reflux
◦Activity reflux from the duodenum into the stomach.
◦Spontaneously in ~8% ◦post op.
vagotomy, hemigastrectomy Bilroth II gastrojejunostomy
1 min/frame static images showing entero-gastric reflux at 30th min
Acute cholecystitis
◦persistent gallbladder non-visualization after 3–4 hr. of passive imaging or 30 min. after morphine administration
◦pericholecystic hepatic band of increased activity (rim sign) has been associated with severe phlegmonous or gangrenous acute cholecystitis, a surgical emergency
RIM SIGN: pericholecystic hepatic band of increased activity
◦Morphine-augmented hepatobiliary scintigraphy has sensitivity, specificity, positive predictive value, and negative predictive value of 95%, 99%, 97%, and 98%, respectively
(c/f USG Abd: positive predictive value of >90% in detecting acute cholecystitis)
Chronic cholecystitis
◦gallbladder visualization within 30 min of morphine administration or on 3-4 hr delayed images
◦gallbladder that is not visualized until after the time that the bowel is visualized correlates significantly with chronic cholecystitis.
Gallbladder EF
◦Normal: ≥ 35%
◦Abnormal: < 35% suggestive of
◦chronic cholecystitis◦cystic duct syndrome◦sphincter of Oddi spasm◦gallbladder dyskinesia
Gallbladder EF
◦The finding of reduced gallbladder ejection fraction in response to Cholecystokinin is a strong indicator of the need for surgical intervention
◦Negative predictive value of a normal gallbladder ejection fraction is >91%,
False positives
(gallbladder non-visualization in the absence of acute cholecystitis)
False negatives
(gallbladder visualization in the presence of acute cholecystitis)
Insufficient fasting bile leak due to gallbladder perforation
Prolonged fasting bowel loop simulating gallbladder
Previous cholecystectomy Acute acalculous cholecystitis
THANK YOU
Causes of enterogastric reflux
Spontaneously in ~8% post op.
◦vagotomy, ◦hemigastrectomy◦Bilroth II gastrojejunostomy
pathophysiologymechanism of reflux is related to the lack of
normally functioning gallbladder. In the absence of the usual storage of bile
with release on cholecystokinin (CCK) stimulation, the patient develops a constant drip of bile into the duodenum.
After meals there is a postdigestive phase of food leaving the stomach, mixing with the bile pancreatic and duodenal secretions, and all being swept downstream in the normal fashion
Two hours after a meal and especially during extended periods of fast, e.g., during sleep, the bile pools in the duodenum, most going downstream and some refluxing backward through the pylorus into the antrum.
In time, the presence of the biliary pancreatic duodenal secretions in the stomach produces such an irritant effect that significant gastritis and esophagitis result.
criteria for the diagnosis of reflux gastritis: ◦constant burning epigastric pain◦worse after meals◦unrelieved by antacids and diet◦endoscopic demonstration of a gastric bile pool◦endoscopic biopsy proof of gastritis and
esophagitis◦hypochlorhydria.
treatment
Medical:◦Bland diet◦Metoclopromide
Surgical:◦Roux-en-Y drainage of the biliary system and
Braun enteroenterostomy (BEE)
Dose Range
◦Adults: 3–5 mCi higher doses (upto 15 mCi) for patients with
elevated bilirubin levels (causes less hepatic uptake, more background activity, and greater renal excretion).
◦For children: 0.05–0.07 mCi per kg minimum dose = 0.3 mCi
Ensure patient
Ensure patient has had. Injection and imaging may be postponed 4 hours if patient has been injected with this type of medication.
Explain the procedure; usually runs ~1 hour but baseline studies can go as long as 4 hours with up to 24-hour delays required in some instances.
indications
Sequential (or dynamic) images of the liver, biliary tree, and gut are obtained.
Computer acquisition and analysis, including pharmacologic interventions, are used according to varying indications and an individual patient’s needs.
No bowel excretion or gallbladder visualization is noted small arrowhead: kidney activitylarge arrowhead:bladder
Normal neonatal hepatobiliary scan