radiology seminar

1. USG BILIARYTREE &GB
DR MOHIT GOEL
4/06/2013

2. GB
Gallstone Disease
Sonography is highly sensitive in the
detection of stones within the
Gallbladder.
The large difference in the acoustic
impedance of stones and adjacent
bile makes them highly reflective,
which results in an echogenic
appearance with strong posterior
acoustic shadowing.
Mobility is a key feature of stones, allowing differentiation from polyps
or other entities.
Various maneuvers may be used to demonstrate mobility of a stone;
scanning with the patient in the right or left lateral decubitus or upright
standing position may allow the stone to roll within the gallbladder.

3. Biliary Sludge
Biliary sludge, also known as biliary sand or microlithiasis, is defined as a
mixture of particulate matter and bile that occurs when solutes in bile
precipitate.
The sonographic appearance of sludge is that of amorphous, low-level
echoes within the gallbladder in a dependent position, with no acoustic
shadowing.

4. Acute Cholecystitis
It is caused by gallstones in more than 90% of patients.
Clinically, patients present with a prolonged, constant RUQ or
epigastric pain associated with RUQ tenderness. Fever,
leukocytosis, and increased serum ALP and bilirubin levels
may be present.

10. Porcelain Gallbladder
Calcification of the gallbladder wall is termed “porcelain” gallbladder.
The degree and pattern of calcification determines the sonographic
appearance.
When the entire gallbladder wall is thickly calcified, a hyperechoic
semilunar line with dense posterior acoustic shadowing is noted.
Mild calcification appears as an echogenic line with variable degrees of
posterior acoustic shadowing.

12. Chronic Cholecystitis
Chronic cholecystitis is associated with the mere presence of gallstones;
therefore patients are usually asymptomatic and have mild disease.
More advanced cases involve wall thickening and fibrosis, appearing on
sonographic examination as a thickwalled gallbladder with gallstones.
Differentiation from acute cholecystitis is made by the absence of other
signs, namely, gallbladder distention, Murphy’s sign, and hyperemia in the
wall.
Bouts of acute cholecystitis may complicate chronic cholecystitis.

13. Adenomyomatosis (Adenomatous Hyperplasia)
Gallbladder adenomyomatosis is a benign condition caused by exaggeration of
the normal invaginations of the luminal epithelium (Rokitansky-Aschoff
sinuses) with associated smooth muscle proliferation.
The great majority of adenomyomatoses are asymptomatic.
Adenomyomatosis may be focal or diffuse.
The most common appearance on sonography is tiny, echogenic foci in the
gallbladder wall that create comet-tail artifacts , presumably caused by either the
cystic space itself or the internal debris.
Prominent mass like focal areas of adenomyomatosis, called adenomyomas,
are the next most common manifestation.
Echogenic foci with ringdown or “twinkling” artifact on Doppler examination
are also typical.

14. Adenomyomatosis: Focal adenomyomatosis, the most common manifestation.
A, Small focal area of thickening of the anterior fundal wall (arrow) with a bright echogenic
focus with a distal comet-tail artifact.
B, Multiple bright foci (arrow)with distal artifacts.
C, Highly echogenic focal thickening of the gallbladder wall (arrow).Increased echogenicity
is unusual for a malignant tumor that is more likely to appear hypoechoic.

15. Polypoid Masses of Gallbladder
Cholesterol Polyps
Approximately one half of all polypoid gallbladder lesions are cholesterol
polyps.These represent the focal form of gallbladder cholesterolosis, a
common nonneoplastic condition of unknown etiology.

16. The sonographic appearance of cholesterol polyps is multiple ovoid,
nonshadowing lesions attached to the gallbladder wall.

17. Gallbladder Carcinoma
The following three patterns of disease have been described:
1. Mass arising in the gallbladder fossa, obliterating the gallbladder and
invading the adjacent liver (most common pattern)
2. Focal or diffuse, irregular wall thickening
3. Intraluminal polypoid mass

18. On Doppler interrogation the mass may demonstrate internal arterial and
venous flow.
Diffuse, malignant thickening of the wall differs from other causes in that
the wall is irregular with loss of the normal mural layers.
Polypoid intraluminal masses are differentiated from nonneoplastic
abnormalities by immobility of the mass, larger size (>1 cm), and prominent
internal vascularity.
Gallbladder carcinomas may produce large quantities of mucin,which distends the
gallbladder

19. Gallbladder cancer:
A and B - Polypoid mass.
B, Examination with high-frequency linear probe shows no invasion beyond the gallbladder
wall.
C, Corresponding coronal MR image shows the enhancing polyp.

20. Huge mass replacing the gallbladder fossa and invading the liver.
H, Biliary obstruction caused by the invasive mass (arrow). I,Corresponding CT scan.

21. BiliaryTree
The normal caliber of the CHD/CBD in patients without history of biliary
disease is up to 6 mm.
Although diameters of up to 10 mm have been recorded in an asymptomatic
normal population, the great majority of the diameters are under 7 mm.
Therefore, a ductal diameter of 7 mm or greater should prompt further
investigations, such as correlation with serum levels of cholestatic liver
enzymes.

22. Choledochal Cysts
Choledochal cysts represent a heterogeneous group of congenital diseases
that may manifest as focal or diffuse cystic dilation of the biliary tree.

23. Type I. Fusiform dilation of the common bile duct is seen, but no obstructive lesion is
noted.This is the most common type of choledochal cyst.

24. Caroli’s Disease
Caroli’s disease is a rare congenital disease of the intrahepatic biliary tree that
results from malformation of the ductal plates, the primordial cells that give
rise to the intrahepatic bile ducts.
Caroli’s disease has been associated with cystic renal disease, most often
renal tubular ectasia (medullary sponge kidneys).
Caroli’s disease leads to saccular dilation or less often fusiform dilation of the
intrahepatic biliary tree, resulting in biliary stasis, stone formation, and bouts of
cholangitis and sepsis.
Cholangiocarcinoma develops in 7% of patients with Caroli’s disease.

28. Primary sclerosing cholangitis.
A, Isoechoic inflammatory tissue causing obliteration of right and left hepatic ducts (arrows)with
proximal dilation.
B, Dilated intrahepatic ducts “rat-tail” as they extend centrally toward the hepatic hilum. Note
the hypoechoic ductal/periductal tissue obstructing the central ducts (arrowheads).
C, Saccular diverticula (arrow)of the duct are occasionally seen.
D, Minute intraductal stones (arrows)are seen in irregular, mildly dilated ducts.

29. Mirizzi Syndrome
Mirizzi syndrome describes a clinical syndrome of jaundice with pain and fever
resulting from obstruction of the common hepatic duct caused by a stone
impacted in the cystic duct.
It occurs most often when the cystic duct and CHD run a parallel course.
Mirizzi syndrome should be considered on sonography when biliary obstruction
with dilation of the biliary ducts to the CHD level is seen with acute or chronic
cholecystitis.
A stone impacted in the cystic duct with surrounding edema at the level of the
obstruction is confirmatory.

31. BiliaryTree Infection
Acute (Bacterial) Cholangitis
The clinical presentation is usually that of
(1) fever (~90%),
(2) right upper quadrant (RUQ) pain (~70%), and
(3) jaundice (~60%), the classicCharcot’s triad.
The sonographic findings of bacterial cholangitis include the following :
• Dilation of the biliary tree
• Choledocholithiasis and possibly sludge
• Bile duct wall thickening
• Hepatic abscesses

33. Cholangiocarcinoma
Cholangiocarcinomas are classified based on the anatomic
location:
1. intrahepatic, also called peripheral (~10%);
2. hilar, also called Klatskin’s (~60%)
3. distal(~30%).
Approximately 90% of cholangiocarcinomas are adenocarcinomas, with
squamous carcinomas the next most common subtype.

34. Peripheral cholangiocarcinoma.
A, Ultrasound, and B,T2-weighted MR, images depict a solid mass encasing
the right hepatic vein. Differentiation from a metastasis is not possible by imaging.

36. THANKYOU