Biliary System Flashcards
Contraindications of Cholecystectomy
- Acute cholecystitis if present for more than 72 hours
- Cholangitis
- Peritonitis
- sepsis
- Pancreatitis
- after pancreatitis has resolved, laparoscopic cholecystectomy is indicated to prevent future pancreatitis.
- Bowel distension
- Portal hypertension
- Morbid obesity
- GB Cancer
what are the locations of this disease?
- Cholangiocarcinoma
- Hilar
- originates from epithlium of main hepatic ducts or junction
- KLATSKIN TUMOUR (image)
- peripheral
- originates from the epithlium of intralobular ducts
- Hilar
Von meyenburg Complex
- AKA bile duct hamartoma/adenoma
- Benign tumour composed of disorganised bile ducts and ductules and fibrocollagenous stroma.
- usually small 1-5mm
- however the nodules may coalesce into larger masses.
- Bile duct hamartoma is benign, however, there have been reports of an association of cholangioca with multiple bile duct hamartomas
Types of biliary enteric fistulae
- Biliary gastric
- biliary duodenal - most common, may cause gallstone ileus
- biliary-colonic
- Bouveret syndrome: obstruction of stomach or duodenum by stone
- Iatrogenic
- ERCP, Surgical
- most common cause for biliary ductal gas
What is this?
Two types?
- Cholangiocarcinoma
- adenocarcinoma of the biliary tree
- Two types
- scirrhous type
- worse prognosis
- Polypoid type
- scirrhous type
- Clincal
- jaundice
- pruritus
- weigh loss
- Rx
- pancreaticodyodenecticomy (whipples)
- palliative procedures
- stent
- biliary bypass
what is this?
Biliary cystadenoma
- uncommon, multilocular cystic liver mass that originates in the bile duct and usually occurs in the right hepatic lobe.
- Typically occurs in women
- h/o chronic abdominal pain
- it may represent a congenital anomaly of the biliary anlage
- COMPLICATIONS
- Malignant transformation cystadenocarcinoma occurs
- IMAGING FEATURES
- well defined and cystic
- internal sepations
- The cyst walls and any other soft tissue components typically enhance with contrast
- variable appearance on MRI depending on the protein content of the fluid and the presence of an intracystic soft tissue component.
Name 3 cystic diseases of the biliary tract
- Choledochal cyst: cyst in the main duct
- Choledochocele: cysts in the main duct at the duodenal opening
- Caroli Disease: Cysts in the small biliary branches within the liver
What is MRCP
- Fat sat T2 imagines of the upper abdo
- bile is hyper intense
- images of the biliary and pancreatic ducts can be rendered by maximum signal intensity projection recons (MIPS)
- Common indications
- unsuccessful ERCP
- ERCP contraindicated
- biliary-enteric anastomoses
- chledochojejunostomy
- billroth II
How common are biliary cancers?
Bilary cancers (adenocarcinoma and cholangiocarcinoma) are the 5th most common GI malignancy
What are the Imaging features of Sclerosing Cholangitis?
- Irregular dilatation
- stenosis
- beading of intrahepatic and extrahepatic bile ducts (seen best on cholangiogram)
- string of beads appearance
- small ‘diverticula’ of biliary tree are PATHOGNOMONIC
What is this?
Adenomyomatosis
- most comon form of hyperplastic cholesterolosis
- marked hyperplasia of the GB wall
- Epithelium herniates into the wall
- forms rokitansky-Aschoff sinuses
- May be focal or diffuse
- IMAGING FINDINGS
- Rokitansky-Ashkoff sinues
- hypoechoic if contain bile
- hyperechoic if contain sludge or calculi
- High amplitude foic in the wall (cholesterol crystals) that produce comet tail artifacts (V shpaed ring down artifacts)
- Thickening of GB wall is common but non specific
- inflammation is not typical
- hypercontractility
- Rokitansky-Ashkoff sinues
- MRI
- Rokitansky-aschoff sinuses
- T1 hypo
- T2 hyper
- non enhancing
- Thickening of GB wall Nonspecific
- Inflammation is not typical
- Rokitansky-aschoff sinuses
Imaging Features for Acalculus Cholecystitis
- No calc
- sludge and debris
- usually in critically ill patients
- same findings as calculous cholecystitis
- Murphys positive
- GB wall thickening
- Pericholecystic fluid
- GB distension
- Hepatic iminodiacetic acid derivative (HIDA) scanning:
- non visualisation of the GB
Name the Ductal anatomy
- Right Hepatic duct
- Right Anterior superior
- Right anterior inferior
- Right posterior superior
- right posterior inferior
- Caudate
- left hepatic duct
- left medial superior segment
- left lateral superior
- left medial inferior
- left lateral inferior
- the RHD and the LHD form the common hepatic duct (CHD) which receives the cystic duct from the GB to form the CBD.
What are the DDx of Sclerosing cholangitis?
3
- Primary biliary cirrhosis
- normal extrahepatic ducts
- AIDS cholangiopathy
- may be a/w ampullary stenosis
- Sclerosing cholangiocarcinoma
whis is this?
what are the types and causes?
sclerosing cholangitis
- Chronic inflammatory process of intrahepatic 20% and extrahepatic 80% bile ducts that causes progressive narrowing.
- Chronic or intermittent obstructive jaundice is evident.
- Types
- Primary (idiopathic)
- Secondary
- IBD (usually UC) 65%
- Cirrhosis
- chronic active hepatitis
- Retroperitoneal fibrosis
- Pancreaittis
- Riedel thyroiditis
- peyronie disease
Imaging findings of Intrahepatic Cholangiocarcinoma
where geographically is it more common?
- More common in asia than in the USA
- Adenocarcinoma from the intrahepatic bile ducts
- Biliary ductal dilatation distal to tumour
- lesions have irregular borders with infiltrative margins
- Delayed peripheral to central enhancement as a result of fibrosis and hypovascularity
- Capsular retraction and vascular invasion.
ERCP/MRCP finding:
Smooth, thick wall, can have a short or long stricture
Association: 1
Autoimmune cholangitis
A/W : autoimmune pancreatitis
What is recurrent pyogenic cholangitis?
which lobes of the liver are most effected?
recurrent pyogenic cholangitis
- endemic disease in asia
- recurrent fever, jaundice, abdo pain
- Cuase
- Clonorchis sinensis and
- Ascaris
- bacterial super infection
- COmmon in asia, young adults
- imaging features
- Biliary dilatation
- extra and intra
- Left lobe and posterior irhgt lobe most common
- biliary strictures
- Intrahepatic calculi
- hepatolithiasis
- contains calcium biilirubinate, cellular debris and mucinous substance
- Typically hyperechoic and casts shaddows
- stones may not be sufficiatnely hyper dense to be detectable by CT
- hepatolithiasis
- Biliary dilatation
- Complications
- intrahepatic abscess formation
- hepatic atrophy as a result of PV occlusion
- Cholangioca.
- PD involvement
- GB disease in 20%
Complications of cholecystectomy
what is this called?
- 0.5-5%
- biliary obstrction
- clipping or thermal injury to CBD
- Postoperative fibrosis
- usually requires percutaneous drainage
- Biliary leak causing peritonitis and/or biloma
- CD stump leak,
- injury to CBD,
- leak from small luschka bile ducts draining directly in GB
- Detection of bile leaks
- HIDA scan
- ERCP
- Transhepatic cholangiogram
- MR with heaptobiliary contrast
- Other
- retained stones
- stones dropped in peritoneal cavity (Morison Pouch)
- Bowel perforation
- Hemorrhage
- infection
- The bile ducts of Luschka, or subvesical ducts, are small ducts which originate from the right hepatic lobe, course along the gallbladder fossa, and usually drain in the extrahepatic bile ducts. Injuries to these ducts are the second most frequent cause of postcholecystectomy bile leaks
Caroli disease
- Segmental cystic dilation of intrahepatic (only) bile ducts
- ie the type 5 subset of choledochal cysts
- Cause unknown
- autosomal recessive
- Sequence of events
- bile stasis predisposes to intrahepatic calculi
- secondary pyogenic cholangitis
- intrahepatic abscesses
- increased risk of cholangiocarcinoma
describe the location of the HA relative to the CBD
- Most common 80%
- HA is between the CBD and the PV
- HA medial to the main PV and
- CBD lateral to the PV
- Less common 20%
- HA anterior to CBD
- HA posterior to PV
ERCP/MRCP finding:
Smoothly narrowed biliary duct, even with stricture
RFs: 2
benign stricture
Risk factors:
recurrent cholangitis
surgical intervention
What are the associations of GB carcinoma?
5
- Cholelithiasis 90%
- IBD (UC > CD)
- Porcelain GB 1%
- familial polyposis
- Chronic cholecystisis
where is the CHD measured on US?
What are the normal measurements?
- CHD measurements (inner wall to inner wall) are performed at the level of the hepatic artery
- Normal measurements
- <7mm in normal fasting patients <60yo
- <10 mm in normal fasting patients >60yo
- <11mm in pts with previous
- surgery
- CBD obstruction
- Fatty meal challenge
- if CHD enlarges more than 2mm after fatty meal, it indicates obstruciton
Complications of Cholecystitis
what is this?
-
Gangrenous cholecystitis
- rupture of GB
- mortality 20%
- Gangrene causes nerve death so that 65% of pts have a negative murphy sign.
- Emphysematous cholecysitis
- rare
- 40% occur in diabetics
- Empyema
https://radiopaedia.org/cases/gangrenous-cholecystitis-3
what is this?
what are the complications?
- xanthogranulomatous cholecystitis
- women begtween 60-70
- RUQ pain
- vomiting leukocytosis
- Postive Murphies
- Gallstones
- marked thickening of GB wall
- Inflammatory changes in contiguous hepatic parenchyma
- difficult to differentiation from adenocarcinoma
- Complications
- perforation
- abscess formation
- fistulous tracts to the duodenum or skin
- extension of the inflammatory process to the liver, colon or surrounding soft tissues
US features of Gall stones
what sign is this?
- posterior shaddow.
- very small stones may not shadow, reposition the patient to heap up calculi
- Mobility of stones
- gravity dependant movememnt
- stones impacted in the neck or stones adherent to the wall will not move
- Wall-echo-shaddow (WES triad, double arc sign) is seen if the GB is contracted (type II) and completely filled with stones
- WES can also be seen with
- porcelain GB
- emphysematous cholecystitis
- highly reflective echo originating from the anterior surface of the calculus
What conditions are a/w this tumour?
cholangiocarcinoma associations
- Image = klatskin tumour
- ASSCIATIONS
- UC
- Chlonorchis exposure in Asian population
- Caroli Disease
- Benzene and toluene exposure
Bismuth classification of bile duct injury
name the types
- Based on the level of traumatic injury in relation to the confluence of the LHD and the RHD
- type 1: Injury >2cm distal to the confluence
- type 2: injury < 2cm distal to confluence
- Type 3: Injury immediately distal to confluence but with intact confluence
- Type 4: A destroyed confluence
Causes and Imaging features of Acute Cholecystitis
- Gallstone obstruction 95%
- Acalculous cholecystitis 5%
- USS features
- Luminal distension > 4cm
- Wall thickening > 5mm edema, congestion
- thickening is usually worse on the hepatic side
- Gall stones
- Cystic duct stones may be difficult to detect if they are not surrounded by bile
- +ve murphy sign
- pericholecystivc fluid
Name variations of papillary insertion
- Ducts within Papillar = ampulla
- the CBD drains into the duodenum through the ampula
- Y type
- CBD and pancreatic duct combine before insertion into ampulla
- 75%
- V type
- CBD and PD insert jointly into ampulla
- 25%
- U type
- CBD and PD insert separately into ampulla
- 5%
- long common channel:
- CBD and PD merge > 1.5cm proximal to ampulla
- increased risk of biliary tract ca.
- Y type
GB Adenoma
- single
- multiple 10%
- 5-20mm
- 60% a/w cholelithiasis
- found in 0.5% of cholecystectomy patients (F > M)
- more common in
- peutz-jeghers
- familial adenomatous polyposis
- Polys >1cm require a careful search for features a/w malignancy
- thickening or nodularity of the GB wall
- evidence of hepatic invasion
- indistinct margin between liver and GB
- bilary duct dilatation
- peripancreatic or hepatoduodenal ligament adenopathy
- GB adenomas are usually smoothly marginated.
- Intraluminal polyploid masse should raise concern for malignancy
- homogeneously hyper echoic
- Can be difficult to distinguish from non calcified gall stones.
Pathology
A wide variety of entities appear as polyps and histology is variable:
-
benign polyps: 95% of all polyps
- cholesterol polyps: >50% of all polyps 3,7,14
- adenoma: ~30%, possibly premalignant 4
- inflammatory polyps: ~10% 14
- other rare entities (see benign tumours and tumour-like lesions of the gallbladder)
-
malignant polyps: 5% of all polyps
- adenocarcinoma: ~90% of malignant polyps
- other rare entities including
- metastases to gallbladder
- squamous cell carcinoma
- angiosarcoma
- Case Discussion
The management and follow-up of gallbladder polyps is controversial and practice varies between centres. However, due to the increased risk of malignancy, polyps measuring 10mm or greater should be considered for cholecystectomy 1.
This patient underwent cholecystectomy and a gallbladder adenoma with low-grade dysplasia was confirmed by histopathology.
what is this?
Mirizzi syndrome is a rare complication of gallstone disease in which a gallstone becomes impacted in the cystic duct or neck of the gallbladder causing compression of the common bile duct (CBD) or common hepatic duct, resulting in proximal obstruction.
The patient may present initially with colicky epigastric pain or manifest with hyperbilirubinaemia (jaundice).
The obstructive jaundice can be caused by direct extrinsic compression of CHD/CBD by the stone or from fibrosis of the same caused by chronic inflammation.
A cholecystocholedochal fistula can occur as a further complication to this condition if left untreated.
Imaging features of Cholangiocarcinoma
- Dilated intrahepatic ducts with normal extra hepatic ducts
- hilar lesions
- central obstruction
- lesions are usually infiltrative so that a mass is not usually apparent
- encasement of PVs causes irregular enhancement by CT
- Peripheral lesions
- may present as a focal mass or be diffusely infiltrative
- retain contrast material on delayed scans
- occasionally invade veins
- ERCP patterns
- short annular constricting lesion 70%
- long stricture 10%
- intraluminal polyploid mass 5%
Ongoing Management post Cholecystostomy
- if there is no cholelithiasis, the catheter is usually left for 3 weeks.
- at this point, the catheter is clamped to make sure that there is adequate internal drainage.
- if the patient tolerates clamping the catheter can be removed,
- if there is cholecystitis, the catheter is left in place until the patient is stable and can undergo a surgical cholecystectomy
- Unlike pts with acalulous cholecystitis, pts with cholelithiasis have an irritant in the GB and thus a reason for inflammation to recur.
what is this?
Bilomas refer to extrabiliary collections of bile. They can be either intra- or extrahepatic.
Terminology
There is a slight discrepancy in the reported literature in the use of the term “biloma”. Many authors have used it exclusively to refer to intrahepatic bile collections or other bilious collections which are discretely organised rather than free biliary leak into the peritoneum (choleperitoneum: a rarely used term).
Clinical presentation
Although usually asymptomatic, they may present with symptomatic bile peritonitis 7.
Pathology
They can result from a number of causes:
spontaneous
trauma
postinstrumentation
transcatheter arterial chemoembolisation (TACE)
percutaneous ethanol injection
microwave ablation
percutaneous biliary drainage
post surgical, e.g. injury to duct of Luschka following cholecystectomy 6
Seventy percent of bilomas are localised to the right upper quadrant, whereas the remaining 30% develop in the left upper quadrant. A biloma may wall off or may continue to demonstrate active bile leakage.
Imaging features of this condition
AKA bile duct hamartoma/adenoma
Von Meyenburg complex
- Can simulate metastases or microabscesses
- therefore histo dx is needed.
- Multiple bile duct hamartomas may simulate mets or hepatic abscesses
- small well-defined hypoattenuating or isoattenuating mass
- little if any hancement
- MRI:
- usually hypo on T1 and
- iso or hyper on T2
- No enhancement post Gd
- USS
- hypoechoic lesions contained central echogenic focus with ring down artifact as a result of cholesterol crystals
ERCP/MRCP finding:
Multifocal intrahepatic strictures and dilatations
RFs: 1
Primary sclerosing cholangitis
RFs: UC
What is chemotherapy cholangitis?
what is the disease hallmark?
- Iatrogenic cholangitis after intraarterial chemotherapy
- ischaemic cholangiopathy
- floxuridine has been used
- strictures of CHD, frequently involving the biliary bifurcation
- sparing of the distal CBD (disease Hallmark)
what is this?
- Choledocholithiasis
- stone in the CBD
- Typically a/w high grade obstection and jaundice
- 75% diagnostic accuracy
Describe the steps of a Cholecystostomy
- Scan liver with USS and choose appropriate entry site
- Go through the liver to minimize the occurrence of a bile leak
- Anesthetise skin
- Place 22-gauge need into GB under US guidance
- Place catheter in GB in Tandem.
- Visualize catheter tip by the US before deploying catheter
- Aspirate bile for culture.
- Connect the catheter to the collecting bag
WHat is this??
Bouveret syndrome is a gastric outlet obstruction produced by a gallstone impacted in the distal stomach or proximal duodenum. It was described by Leon Bouveret in 1896 (,1) and occurs most commonly in elderly women with a mean age of 68.6 years (,2).
ERCP/MRCP finding:
irregular biliary duct with abrupt luminal narrowing
RFs: 4
cholangiocarcinoma
Risk factors:
PSC
UC
Liver parasites
choledochal cysts
Name variants of Cystic Duct Insertion
- Normal
- low union
- parallel course
- anterior spiral course
- posterior spiral course
what is this?
Peribiliary Cysts
- Peribiliary cysts occur in the setting of chronic liver disease where it is a rare, benign, and often asymptomatic disorder. They consist of cystic formations around the intrahepatic biliary ducts, primarily in a hilar distribution. Unlike choledochal cysts (for example in Caroli disease), peribiliary cysts do not communicate with the biliary tree.
- Related to the peribiliary glands.
Differential diagnosis
Imaging differential considerations include:
- von Meyenburg complexes: although in this setting biliary hamartomas are more diffuse throughout the liver rather than hilar in distribution and would be more space out
- Caroli disease: a congenital disorder involving multifocal intrahepatic choledochal cysts of the segmental intrahepatic bile ducts
what is this?
What is the clinical triad
What types/forms of this are there?
- Choledochal cysts
- cystic dilatation of the CBD
- type I fusiform
- Type II saccular/diverticulum
- lined with duodenal mucosa
- Tupically occur in children and young adults
- most common in Japan/asia
- 20 fold increased risk of bile duct malignancy they are usually excised.
- cystic dilatation of the CBD
- Clinical triad
- jaundice
- abdopain (infection of bile)
- Palapble mass.
What is the indication for percutaneous Biliary drainage?
What are the steps?
- Indication: Biliary obstruction
- steps after transhepatic cholangiogram:
- after cannulation of the bile duct, advance a nitinol guidewire (or the guide wire that comes with the one-stick access set) through the needle into the biliary system.
- Obtain as much purchase as possible.
- Remove needle
- Pass plastic catheter over guidewire.
- exchange guide wire for a 0.038 metal wire or Terumo, pass guidewire indo duodenum
- Dilate skin tract up to 12 Fr
- Place drainge catheter over guide wire (Cope, Ring catheters)
- Perform catheter injection with contrast material to adjust placement of side holes.
what is this
Cholesterolosis Strawberry GB
- Triglucerides and cholesterol are deponsitied in macrophages of the GB wall.
- The cholesterol nodues stud the wall and give the GB the appearance of a strawberry
- lipd deposits are echogenic and <1mm
- no shadowing
- inflammation is not a prominent feature
- a/w multiple 0.5-1mm polyps
- https://www.ultrasoundcases.info/unusual-cases-3748/
What are the indications for Transhepatic Cholangiogram?
- Demonstration of biliary anatomy.
- the first step before biliary drainage or stent placement.
- PROCEDURE
- RIGHT HEPATIC LOBE
- Antibiotic coverage is routine
- use a lateral midaxillary approach, advance one-stick system into the liver
- attach extension tubing and syringe filled with contrast
- slowly inject contrast while retracting the needly under fluoroscopy
- repeat until opacification of bile ducts
- LEFT HEPATIC LOBE
- Antibiotic coverage is routine
- use a midline approach, advance one stick system into a biliary radical under US guidance.
- attach extension tubing and syringe filled with contrast
- slowly inject contrast during fluoroscopy to confirm the biliary placement of the needle
- Ensure the syringe is air-free in order to not obscure the view for future attempts.
- RIGHT HEPATIC LOBE
what is this?
The concentration of intravesicular calcium salts in longstanding cystic duct obstruction.
Radiographically, GB contents appear dense
What sign is this and what are the other
Imaging features of Caroli disease?
- Multiple cystic structures converging toward porta hepatis
- beaded appearance of intrahepatic bile ducts
- most of the cysts arranged in a branching pattern
- central dot sign
- very specific sign of Caroli disease in which portal radicals are partially or completely surrounded by abnormally dilated and ectatic bile ducts on both sonography and CT
- Sludge, calculi in dilated ducts
ERCP/MRCP finding:
round filling defects
- Biliary stones
associations of caroli disease
2
- Medullary sponge kidney 80%
- Infantile polycystic kidney disease
Gall Bladder variants
- Phrygian cap
- junctional fold
- fold between infundibulum and body. May be hyperechoic and cause posterior shaddowing
- Agenesis of the GB Rare
- more common causes of nonvisualised GB
- previous cholecystectomy
- non fasting
- chronic cholecystitis
Name variations in Hepatic duct anatomy
- normal in 60%
- Right posterior ducts drain directly into LHD 20%
- RIght posterior duct right anterior duct and LHD form the CHD 10%
What is a cholecystostomy and who is it performed in?
- Percutaneous cholecystostomy is often performed for acalculous cholecystitis in ICU patients with unexplained sepsis.
- In these patients USS findings are not helpful in making the dx of acute cholecystitis and a trial of cholecystostomy is often warranted
- clinical response is typically seen in 60% of pts
Risk factors for Acalculus Cholecystitis
- Trauma
- Burns
- Prolonged fasting
- hyperalimentation
- diabetes
- AIDS
- COlitis
- hepatic arterial chemo
- post partum
- vascular insufficiency
overview
Acalculous cholecystitis is defined as cholecystitis that occurs without a gallstone.
This typically occurs in critically ill patients due to a combination of factors (e.g. bile stasis and hypoperfusion).
Acalculous cholecystitis often goes unrecognized initially, because of intubation and sedation. This can lead to a high rate of progression to gallbladder necrosis (50%) and perforation (10%).
The term “necrotizing cholecystitis” has been proposed for this disease, to emphasize its potentially malignant course.
pathogenesis
Pathogenesis may be summarized roughly as follows. In some ways, this may be conceptualized as a paralytic ileus of the gallbladder.
(1) Lack of enteral nutrition and hypoperfusion create a hypotonic, dilated gallbladder.
Distension of the gallbladder increases wall tension, further impairing perfusion of the gallbladder wall.
Biliary stasis causes concentration of biliary detergents, which may damage the gallbladder wall.
(2) Further complications ensue:
Necrosis and perforation of the gallbladder may occur.
Superinfection with enteric bacteria may occur (empyema of the gallbladder). Note that many cases of acalculous cholecystitis occur without bacterial infection.
https://emcrit.org/ibcc/acalculous-cholecystitis/
USS features of Chronic Cholecystitis
- GB wall thickening
- fibrosis
- chronic inflammation
- Rokitansky-Aschoff sinuses (intramural epithelial crypts)
- Gallstones
- Failure of GB to contract in response to CCK
- Porcelain GB:
- wall calcifications
- increased risk of GB carcinoma
- Thickened gallbladder wall. Streaky echogenic lines from the anterior GB wall in keeping with comet-tail artifact. No gallstones.
Case Discussion
The comet-tail artifact is a type of ultrasound reverberation artifact caused by cholesterol crystals being trapped within Rokitansky-Aschoff sinuses in gallbladder adenomyomatosis.
What is this??
- acute cholangitis
- Infection of obstructed bile ducts
- Ecoli > klebsiella > pseudomonas
- Causes
- choledocholithiasis
- stricture
- Sclerosing cholangitis
- Infected drainage Catheter
- Ampullary Carcinoma
- Imaging features
- Dialtation of intrahepatic ducts
- dialted CBD
- pigment stones and sludge in intrahepatic bile ducts
- pathognomonic
- Segmental hepatic atrophy
- Liver abscess, pancreatitis
- Dialtation of intrahepatic ducts
Figure 2 BAC in a patient with CBD stones. Coronal image from contrast material–enhanced multidetector computed tomography (CT) shows pus (arrowhead) layering within one of several dilated intrahepatic ducts (arrows). Intra-ductal sludge could have the same appearance. The patient underwent biliary drainage; abundant pus was aspirated.
https://pubs.rsna.org/doi/10.1148/rg.297095051
