Radiological anatomy of hepatobiliary system.

1. RADIOANATOMY
OF
BILIARY SYSTEM
DR. AKANKSHA MALVIYA
JR-2 Department of Radiology
SAIMS,Indore

2. Bile is a bi-product of
degraded heme part of old
red cells.
It is secreted by the liver
,transported through
biliary channels to gall
bladder where it is stored,
concentrated and later
delivered to the duodenum

3. DEVELOPMENT OF BILIARY APPARATUS
4th week

4. The endodermal
cells of hepatic bud
give rise to
parenchyma of the
liver and to bile
capillaries.
Bile formation
begins when the
fetus is about three
months old.

6. PARTS OF BILIARY TREE

7. ON MAGNETIC RESONANCE
CHOLANGIOPANCREATOGRAPHY (MRCP)

8. ON ENDOSCOPIC RETROGRADE
CHOLANGIOPANCREATOGRAPHY (ERCP)

9. ANATOMY OF BILIARY TREE
• Biliary tree is divided into:
1. Intrahepatic ducts
2. Extrahepatic ducts

10. INTRAHEPATIC DUCTS
Bile canaliculi
Canals of Herring
Bile ductules
Right and Left hepatic ducts

13. • has a variable
drainage
pattern but in
majority,
ducts.
• anterior division -
segment 5 & 8
• posterior division -
segment 6 & 7.
Rt.hepatic
duct
• segment 2,3 &
4 of left lobe.
Lt.Hepatic
duct
• 78% drainage
is into both
main
Caudate
lobe

14. Right and left hepatic ducts (short arrows) are normally seen lying anterior to the portal veins.

16. • On ULTRASONOGRAPHY :
Signs of Biliary Dilatation : Parallel Channel sign – IHBD > 2mm
, CBD > 6mm
 Post Fatty Meal Sonography : CBD size increase of 2mm
Post Cholecystectomy : No compensatory dilatation of CBD, CBD
> 10mm

17. Dilated Intrahepatic Biliary Ducts on CT Scan

18. EXTRAHEPATIC BILIARY APPARATUS
• The right and left
hepatic ducts fuse at the
hilum ,anterior to
bifurcation of the portal
vein to form Common
Hepatic Duct which is
then inserted by cystic
duct from the gall
bladder and becomes
Common Bile Duct .

19. • The CBD passes inferiorly
posterior to the first part of
duodenum and pancreatic
head to enter the second part
of duodenum along with the
main pancreatic duct at
Ampulla of Vater.

20. The picture above shows in better detail the Ampulla
of Vater and its entrance into the common bile duct.
The Ampulla of Vater and the Sphincter of Oddi are
very close in location, remember that the sphincter of
Oddi controls the opening of the ampulla of Vater, and
is a separate entity.

21. • Most commonly, the two ducts join in the duodenal wall and have
a short common channel.
• Occasionally, separate orifices are present at the ampulla, or the
ducts unite, forming a long common channel before entering the
duodenal wall.

22. Common hepatic/common bile ducts of
normal caliber in sagittal view lying in the
typical position anterior to the portal vein
and hepatic artery.

23. c) Mid and distal CBD in longitudinal view. Note the pancreas (*), the cranial margin of which
demarcates the transition between suprapancreatic and intrapancreatic segments.
d) Distal CBD and the ampulla of Vater (short arrow) are shown running posterior to the pancreatic head
and inserting into the duodenum (D)

24. Intra and extra hepatic bile ducts on MRCP

25. GALL BLADDER
• Location :
1. Epigastric region
2. Right hypochondriac
region
3. On inferior surface of liver
4. Between quadrate and
right lobes .
• Pear‐shaped, hollow
structure

26. PARTS OF GALL BLADDER

27. NORMAL ULTRASOUND OF GALL BLADDER

28. GALL BLADDER FOLDS
LONGITUDINAL VIEW OF GALL
BLADDER

32. ACOUSTIC SHADOW FROM GB FOLD
Part of a fold within gallbladder producing
an acoustic shadow .
When only part of fold is visualized, it may
mimic a polyp or a stone.

33. EDGE REFRACTION SHADOW
• Shadow near neck of GB
on longitudinal section.
• Absence of visible stone o
the origin of shadow.
 Scan in different position .

34. CYSTIC DUCT
• The gallbladder is attached to the common bile duct (CBD) via
the cystic duct
• usually 2 to 4 cm long and contains tortuous folds, the spiral
valves of Heister .
• Diameter 2-3 mm.

35. PROXIMAL CYSTIC DUCT

36. DISTAL CYSTIC DUCT

37. ANATOMIC VARIANTS IN THE CYSTIC DUCT.
Anatomic variants in the cystic duct. Drawings illustrate how the cystic duct may insert into the
extrahepatic bile duct :
right lateral insertion (A), anterior spiral insertion (B), posterior spiral insertion (C), low lateral
insertion with a common sheath (D), proximal insertion (E), or low medial insertion (F).

38. Figure 1: Coronal oblique 3D MR
cholangiopancreatography shows normal
insertion of cystic duct at middle 3rd of
common hepatic duct from lateral aspect
(arrow).

39. Figure 2: Coronal oblique 3D MR
cholangiopancreatography shows
spiral course of cystic duct (white
arrow) with medial insertion with
CHD. GB: gall bladder.

40. Figure 3: Coronal oblique 3D
MR cholangiopancreatography
shows low medial insertion of
cystic duct where cystic duct
(arrow) drains at lower 3rd of
CHD from left side.

41. Figure 4: Coronal oblique 3D
MR cholangiopancreatography
shows parallel course of cystic
duct (white arrow) and CHD
(white arrowhead). Also note
medial insertion of cystic duct
(red arrow). GB: gall bladder.

42. Figure 5: Coronal oblique 3D MR
cholangiopancreatography shows
high insertion of cystic duct at
upper 3rd of CHD from lateral
aspect.

43. Figure 6: (a) Coronal oblique 3D
MR cholangiopancreatography.
shows short cystic duct with
anterior insertion (arrow) into
the CHD (arrowhead). GB: gall
bladder.

44. Figure 7: Coronal oblique 3D MR
cholangiopancreatography shows
aberrant insertion of cystic duct
(red arrow) into the right hepatic
duct (white arrow) and low union of
right and left hepatic duct (blue
arrow). Also note multiple calculi
(black arrow) in common bile duct
(white arrowhead). A: right anterior
sectoral duct, P: right posterior
sectoral duct, RHD: right hepatic
duct, LHD: left hepatic duct, CD:
cystic duct, and GB: gall bladder.

45. ARTERIAL SUPPLY
Three segments of supply.

48. DEVELOPMENTAL INTRAHEPATIC BILIARY
ANOMALIES
Right posterior duct (RPD) is in red.

51. EXTRAHEPATIC BILIARY ANOMALIES
CLASSIFICATION OF GALL
BLADDER ANOMALIES

52. AGENESIS OF GB
1 in 6,000 life births – fewer than 300 reported cases
• Agenesis Of The Gallbladder Agenesis of the gallbladder is caused by
failure of development of the caudal division of the primitive hepatic
diverticulum or failure of vacuolization after the solid phase of
embryonic development.
• Other congenital anomalies are present in two thirds of these patients,
including congenital heart lesions, polysplenia, imperforate anus,
absence of one or more bones, and rectovaginal fistula.
• The surgical incidence of gall bladder agenesis is approx. 0.02%.

53. • There are two main expressions:
1) AGB without cystic duct remnant and 2) AGB with cystic remnant .
• Ultrasound or CT may suggest the diagnosis, but it is usually diagnosed
at surgery when the gallbladder is not found at cholangiography.

54. AGENESIS OF GALL BLADDER

55. Absence of gallbladder and cystic duct on MRCP (blue
arrow marks common bile duct).

56. DUPLICATION OF THE GALLBLADDER
(VESICA FELLEA DUPLEX)
1 in 4000 people
• This anomaly is caused by incomplete revacuolization
of the primitive gallbladder, resulting in a persistent
longitudinal septum that divides the gallbladder
lengthwise / occurrence of separate cystic buds.
• To establish the diagnosis, two separate gallbladder
cavities, each with its own cystic duct, must be
present.
• These duplicated cystic ducts may enter the common
duct separately or form a Y-configuration before a
common entrance.
• Most reported cases of gallbladder duplication have a
clinical picture of cholecystitis with cholelithiasis in at

57. Duplicated gall bladder
Picture courtesy : Dr. Sudheer Gokhale Sir, Mohak Hi-tech Speciality Hospital,Indore.

58. 3D Coronal MIP image of
MRCP demonstrates
duplication of gallbladder
(stars) with two cystic ducts
(arrow heads)
CT abdomen scan coronal (b) and sagittal (c) reformated
sections show two separate cystic structures in
gallbladder fossa. Superior and anteriorly placed normal
inflamed gallbladder and the duplicated gall bladder
(arrow) posteroinferior in position to the normal
gallbladder.

59. THE BILOBED GALLBLADDER
( VESICA FELLEA DIVISA)
• structure having two separate fundic cavities, united at their bases and joined to the
ductus choledochus by a single cystic duct.
• It is differentiated from double/accessory GB by presence of independent cystic
ducts, draining individual fundic cavities of the latter type.

60. WANDERING GALLBLADDER
• When the gallbladder has an unusually long mesentery, it can “wander” or
“float.”
• A wandering gallbladder typically is attached to surrounding structures only by
the cystic duct and its mesentery.
• Its characteristic propensity for torsion places it at risk for necrosis.
• The gallbladder may “disappear” into the pelvis on upright radiographs or
wander in front of the spine or to the left of the abdomen.
• Rarely, the gallbladder can herniate through the foramen of Winslow into the
lesser sac.
• The herniation can be intermittent and may be responsible for abdominal pain.

61. • Most cases of gallbladder torsion occur in women (F/M ratio of 3:1).
• The usual preoperative diagnosis is acute cholecystitis.
• Gangrene develops in more than 50% of cases and is extremely common when the pain
has been present for more than 48 hours.
• On cross-sectional imaging, the gallbladder is distended and may have an unusual
location and show mural thickening.
Prone radiograph as a part of an oral cholecystogram
reveals the opacified gallbladder (curved arrow) to Lie in
the left upper pelvis. This excessive mobility represents a
"wandering gallbladder."

62. Computerized tomography showing a
low-lying gallbladder (white arrow)
and a horseshoe kidney.
Figure 1: Reconstructed coronal images on computed
tomography demonstrating the dilated and relatively
inferiorly placed gallbladder.Acute gastric distension was
also present due to duodenal compressionby the very
dilated gallbladder (not shown).
Figure 2: Intraoperative view of gangrenous wandering
gallbladder
(G) completely separate from the liver (L) and torted
clockwise
around the cystic duct and mesentery (C).

63. ANOMALOUS LOCATION / ECTOPIC
GALLBLADDERRARE
– REPORTED ONLY IN ISOLATED CASE REPORTS
Most common locations
• Left side (posterior to left lobe)
• Intrahepatic
• Suprahepatic (right lobe & diaphragm)
• Retrohepatic (posterior to right lobe)
Intrahepatic gall bladder

65. MULTI-SEPTATE GALLBLADDER
CONGENITAL ORIGIN – VERY RARE
• Entire GB or part of lumen
• Chambers communicate by orifices
• Isolated or coexist with other
anomalies
• Symptoms of recurrent cholecystitis
• Multiple linear fine echogenic
septations- Oriented horizontally or
vertically

67. TRUE DIVERTICULUM OF GALLBLADDER
• Extreme rarity
• Occurs anywhere in GB
• Usually singleVaries greatly in size
• Congenital diverticula are true
diverticula and contain all the mural
layers, as opposed to the
pseudodiverticula of adenomyomatosis,
which have little or no smooth muscle
in their walls.

68. TRUE DIVERTICULUM OF GALLBLADDER

69. CHOLEDOCHAL CYSTS
• Choledochal cysts are congenital cystic dilatations of any portion of extra hepatic bile
ducts, most commonly the main portion of CBD.
• It is postulated that this condition begins with an anomalous junction of the common
bile duct and pancreatic duct proximal to the duodenal papilla.
• Higher pressure in pancreatic duct combined + an absent ductal sphincter allows free
reflux of enzymes into biliary tree, weakening wall of the common bile duct.

70. • Diagnosis of a choledochal cyst is made on the basis of disproportional dilatation of the
extrahepatic bile ducts after excluding the possibility of a tumor, stone, or inflammation
as the cause of the dilatation.
• The estimated incidence of choledochal cysts in Western countries varies between 1 in
100,000 and 1 in 150,000 individuals.
• 60% of patients present before age 10, although choledochal cysts can present from
birth to old age.
• This anomaly is associated with increased incidence of GB anomalies, biliary
anomalies ( stenosis /atresia), and congenital hepatic fibrosis.
• Complications of choledochal cysts in adults include rupture with bile peritonitis,
secondary infection (cholangitis), biliary cirrhosis and portal hypertension, calculus
formation, portal vein thrombosis, liver abscess, hemorrhage, and malignant
transformation into cholangiocarcinoma.

71. TODANI
CLASSIFICATION

75. TYPE-1
CHOLEDOCHAL
CYST ON USG

76. Presentation
Neonatal jaundice
Patient Data
AGE: 15 months
GENDER: Female
Choledochal cyst with dilated bile ducts in left and right
liver lobes.

77. CAROLI’S DISEASE
• Caroli’s disease, also known as communicating cavernous ectasia, is
characterized by multifocal segmental saccular dilatation of the intrahepatic
bile ducts, a predisposition to biliary calculi and cholangitis, and an
association with various forms of cystic renal disease.
• It is an autosomal recessive disease secondary to the ductal plate
malformation.
• It is associated with polycystic kidney disease, medullary sponge kidney and
medullary cystic disease.
• Caroli’s disease usually manifests in adulthood; however, it can be seen in
newborns and infants.
• Adult patients present with recurrent attacks of cholangitis and crampy
right upper quadrant pain with occasional fever and mild jaundice.

78. • Infants and children may present with hematemesis caused by portal
hypertension from hepatic fibrosis.
• Complications of Caroli’s disease include stone formation (95%) within the
dilated intra-hepatic ducts, recurrent cholangitis, and liver abscess.
• There is also a 100-fold increase in incidence of bile duct carcinoma, occurring
in 7% of patients.
• Caroli’s disease is best demonstrated by cholangiography which shows
saccular dilatations of the intrahepatic ducts, stones, strictures, and
communicating hepatic abscesses.

79. Ultrasound :
• May show dilated intrahepatic bile ducts (IHBD).
• intraductal bridging: echogenic septa traversing the dilatedbile duct lumen.
• small portal venous branches: partially/completely surrounded by dilated bile
ducts.
• intraductal calculi.

80. CT :
• multiple hypodense rounded areas which are inseperable from the dilated intrahepatic
bile ducts
• “centraldot” sign: enhancing dots within the dilated intrahepatic bile ducts, these
intraluminal dots correspond to intraluminal portal veins.
MRCP with three-dimensional display is an accurate method for demonstrating Caroli’s
disease because the luminal contents of the bile ducts appear hyperintense in contrast
to the portal vein, which usually appears as signal void.
Cystic expansions of the intrahepatic biliary tract are depicted as oval- shaped
structures in continuity with the biliary tract.

82. BILIARY ATRESIA
• Biliary atresia is a congenital biliary disorder, which is characterised by an
absence or severe deficiency of the extra-hepatic biliary tree .
• It is one of the most common causes of neonatal cholestasis, often causing
cirrhosis immediately and leading to death and accounts for over half of children
who undergo liver transplantation.
• Incidence- 1 in 10,000-15,000 newborn infants.
• There is a recognized male predilection.
• Luminal obstruction of the extrahepatic bile duct with a fibrous ductal remnant is
the pathology.

83. • Infants with biliary atresia may appear normal & healthy at birth.
• Most often, symptoms develop between 2wks-2mnths, and may include :
Jaundice Dark yellow or brown urine Pale or clay-colored (acholic)
stools Hepatomegaly.
• Affected neonates have associated congenital defects, including situs
inversus, polysplenia, malrotation, intestinal atresia, and cardiac
anomalies.

84. Kasai Classification of biliary atresia

85. • Ultrasound
 Echogenic triangular cord sign : Tubular echogenic cord of fibrous tissue
seen in the porta hepatis at ultrasonography and is relatively specific in
diagnosis of biliary atresia.
It is defined as more than 4 mm thickness of echogenic anterior wall of right
portal vein (EARPV) measured on a longitudinal ultrasound scan.
 Gallbladder ghost triad : Atretic gallbladder, length less than 19 mm
Irregular or lobular contour Lack of smooth/complete echogenic
mucosal lining with indistinct wall Larger hepatic arterial calibre

87. TRIANGULAR CORD SIGN

89. ANOMALOUS PANCREATICOBILIARY
DUCTAL JUNCTION
• Found in all the patients of choledocal cyst, but not vice versa
• More commonly associated with cholangiocarcinoma
• Most Reliable method for diagnosis – ERCP

92. INVESTIGATION
Radiological investigations comprise of :
• Plain radiograph
• Ultrasound
• Computed tomography
• Magnetic resonance imaging
• Radionuclide imaging
• Indirect cholangiography

93. PLAIN RADOIGRAPH
• Plain radiograph is usually taken as part of sequence of investigation
of abdominal pain.
• It gives information about radiopaque stones, mural calcification,
mural gas and gas in biliary tree.

94. ULTRASOUND
• the first line investigation particularly calculous disease(over 98%
accuracy).
• U/S detects dilated Intrahepatic and extrahepatic ducts, cholelithiasis,
cholecystitis, GB polyp, choledochal cyst etc

95. ENDOSCOPIC ULTRASOUND (EUS)
• This provides high-frequency grey-scale imaging (± colour Doppler) for
the evaluation of the extrahepatic biliary tree, pancreas and duodenum
▸ it can also allow fine-needle aspiration cytology to be performed

97. COMPUTED TOMOGRAPHY
• The sensitivity of CT in differentiating hepatocellular from obstructive
jaundice and in determining the level and cause of obstruction
parallels that of ultrasound.
• CT is reserved for those patients in whom there is doubt as to the
cause of obstruction and in staging of biliary tumours.

98. MAGNETIC RESONANCE
CHOLANGIOPANCREATOGRAPHY (MRCP)
Technique
• Heavily T2-weighted coronal oblique fast spin-echo sequence to obtain source data (aligned
along the plane of the common bile duct [CBD])
■ Stationary water appears as areas of high SI and adjacent soft tissue is low SI (therefore it is
not reliant on contrast excretion and can be used in jaundiced patients)
■ Fasting reduces any unwanted signal from the adjacent intestine
• Source data allows MIP reformats to be generated (highlighting fluid-filled structures) –
usually a number of coronal MIP reformats over 180°
• Secretin: this stimulates exocrine pancreatic secretion, distending the pancreatic duct and
improving its visualization (acts immediately, returning to baseline at 10 min)
■ Uses: liver donor transplant work-up ▸ the assessment of bile leaks and biliary
communication with cysts ▸ the demonstration of segmental obstruction

99. HEPATOBILIARY SCINTIGRAPHY
• Hepatobiliary iminodiacetic acid (HIDA) scintigraphy: this is a bilirubin analogue
labelled with 99mTc
■ It is injected intravenously with serial images obtained over 2–4 h (it requires
near-normal bilirubin levels)
• There is normally accumulation of isotope within liver, bile ducts, gallbladder,
duodenum and small bowel by 1 hr
■ Delayed hepatic activity: hepatocellular disease (with corresponding elevated
bilirubin levels)
■ Non-demonstration of the gallbladder: acute cholecystitis ▸ a contracted
gallbladder (e.g. following a recent meal)

100. HIDA SCAN

101. ENDOSCOPIC RETROGRADE
CHOLANGIOPANCREATOGRAPHY (ERCP)
• This allows direct bile and pancreatic duct opacification, as well as visual
assessment of the duodenum and ampulla of Vater
■ It also allows for: biopsy ▸ brushings ▸ sphincterotomy ▸ stone extraction
▸ biliary stenting ▸ biliary stricture dilatation
• The main complication is the precipitation of pancreatitis
• The main pitfall is the presence of underfilled ducts above a stricture

102. INDIRECT CHOLANGIOGRAPHY / ORAL
CHOLANGIOGRAPHY
• It has a limited role in anatomical and
functional assessment of gall bladder but
the diagnostic accuracy in
demonstrating gall stones is upto 90%.
• The media commonly used is
 sodium ipodite (Biloptin),Calcium
ipodite(Solubiloptin).

103. PERCUTANEOUS CHOLANGIOGRAPHY (PTC)
• Direct puncture of the intrahepatic ducts using a fine-gauge Chiba needle
allows demonstration of biliary tree with relative safety.
• INDICATIONS
 Obstructed jaundice with or without duct dilatation.
 In defining biliary-enteric or biliary-cutaneous fistulas.
 In defining levels of bile leak.
 To map biliary tree as a preliminary to establish external or internal biliary
drainage with stent placement.

104. PERCUTANEOUS TRANSHEPATIC
CHOLANGIOGRAPHY

105. OPERATIVE CHOLANGIOGRAPHY
• Operative cholangiography prior starting surgical procedure is done commonly at
the time of cholecystectomy for:
 Exploration of CBD
 Anomalous duct anatomy
 Developmental disorders of biliary tree.
 Postoperative cholangiography through a T-tube is indicated to ensure removal of
all stones.

106. T-TUBE CHOLANGIOGRAPHY