Biliary System Flashcards
What kind of structures are the gallbladder and biliary tract?
Intraperitoneal
What are the three sections of the gallbladder?
Fundus
Body
Neck
What duct does the gallbladder neck connect to?
Cystic duct
The confluence of what ducts creates the common bile duct?
Common hepatic duct
Cystic duct
What is the typical length of the gallbladder?
7-10 cm
What is the normal thickness of the gallbladder wall?
Less than 3 mm
Less than 0.3 cm
Where is bile produced?
In the liver parenchyma
What duct takes bile in and out of the gallbladder?
Cystic duct
The confluence of what two ducts creates the ampulla of Vater?
Common bile duct
Pancreatic duct
What is the function of the sphincter of Oddi?
Regulates the flow of bile into the intestinal system
What is the normal measurement of the common bile duct?
Less than 6 mm in dia
How does the CBD diameter increase?
It increases 1 mm for every decade of life after 60
What is the primary role of the gallbladder?
To store, concentrate, and release bile
What triggers the release of bile into the duodenum?
Proteins and fatty acids in the stomach
What is the main lobar fissure?
Echogenic linear structure between the gallbladder neck and the portal vein
Why is the main lobar fissure important in ultrasound?
It helps differentiate the gallbladder from liver vasculature
What causes the gallbladder posterior enhancement?
The duodenum with bowel gas
What is the Hartmann’s pouch?
When there is a small outpouching along the gallbladder neck
What is a Phrygian cap?
When the fundus folds on itself
What do the bile ducts, hepatic artery, and portal vein walls look like on ultrasound?
Echogenic
What do the hepatic vein walls look like on ultrasound?
Thin and dull
Where does the main portal vein arise from?
The confluence of the superior mesenteric and splenic veins
Where does the hepatic vein drain?
Into the IVC
What do the bile ducts and gallbladder show on color Doppler?
No flow
What kind of flow does liver vasculature have?
Hepatic artery and portal vein are hepatopedal
Hepatic veins are hepatofugal
What is the correct method for measuring the CBD?
From inner wall to inner wall in long axis
What is the sonographic difference between the gallbladder and intestinal loops?
Intestinal walls are hypoechoic and have echogenic lumen
Gallbladder has hyperechoic walls and a echoing lumen
What is patient preparation for biliary tree scanning?
NPO for 6-8 hours before exam
Why should a patient be NPO before biliary scanning?
Ensures the gallbladder will be dilated
Minimizes bowel gas
What are the basic objectives for imaging the gallbladder and biliary tract?
Visualize the biliary system in two planes in two body positions (supine, LLD)
Scan gallbladder from fundus through neck
Measure the thickness of the anterior gallbladder wall
Measure CBD diameter
Is the gallbladder always in the same location?
No, it depends on body habitus
Where is the gallbladder likely located in thinner patients?
Anteriorly located in subcostal position
Beam directed toward head
Where is the gallbladder likely located in heavier patients?
More laterally located
X-7 approach - start in subxiphoid position and move 7 cm laterally
What major structures should be included in biliary scanning?
Gallbladder in long and trans
Intrahepatic and extrahepatic ducts
Pancreatic head with common bile duct
What measurements are suggested for biliary scanning?
Anterior wall of gallbladder
Bile duct in ports hepatis
What is the maximum measurement for the the bile filled gallbladder?
9 cm
What aspect is the common duct is considered the common bile duct?
The distal
What congenital sonographic finding can appear similar to an hourglass?
Bilobed
What sonographic finding is associated with the presence of stone in the ductal system?
Choledocholithiasis
What clinical indication presents as yellowish skin?
Jaundice
What imaging test is used to test the function of the gallbladder?
HIDA scan
What is the widest portion of the gallbladder?
Fundus
What does the extrahepatic portal triad consist of?
Left portal vein
Left hepatic artery
Common bile duct
What ducts form the ampulla of Vater?
Pancreatic and bile ducts
What circle of muscle fibers surrounds the ampulla of Vater?
Sphincter of Oddi
What is the neck of the gallbladder fixed to?
Main lobar fissure
What do the walls of the gallbladder look like?
Echogenic
What do the walls of the hepatic artery, portal vein, and bile duct look like?
Echogenic walls
No color doppler flow
Where does the CBD deliver bile?
Into the duodenum
What regulates the CBD?
Sphincter of Oddi
Where does the CBD run?
Anterior and parallel to the portal vein
How does the gallbladder concentrate bile when fasting?
By reabsorbing water and electrolytes
The sphincter of oddi is closed
Bile goes to the liver through the cystic duct
What is the function of cholecystokinin?
Causes the liver to synthesize more bile and the sphincter of oddi to open
What are the vasculature included in the Mickey Mouse sign?
Left ear is CBD
Right ear is HA
Head is PV
How do you scan the gallbladder?
Hold deap breath
Two planes in two positions
What is the normal diameter of the CBD?
< 7 mm
How do stones appear in the biliary system?
Echogenic stones within anechoic lumen that cause posterior shadowing
Increased gallbladder wall thickness and elnarged gallbladder lumen
What are the risk factors of gallstones?
The five F’s
Fat, female, forty, fertile, and fair
What are symptoms of gallstones?
Sharp epigastric or RUQ pain
Shoulder/back pain
Nausea/vomiting
