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IMAGING OF CYSTIC LIVER 

DISEASES 

S Mezghani Boussetta, M Jaber, KH Bouzaïdi*, S Gharbi, 

MM Azouz* 

Department of Radiology, General Hospital of BenArous 

*General Hospital Med Taher Maamouri. Nabeul

INTRODUCTION 

Cystic lesions of the liver in the adult can be classified as: 

– developmental 

– neoplastic 

– inflammatory 

– miscellaneous lesions 

Because of the clinical implications and therapeutic 

strategies for cystic focal liver lesions, the ability to 

differentiate non invasively all types of cystic tumors is 

extremely important.

INTRODUCTION 

Ultrasonography is very sensitive to identify cystic lesions 

and their internal morphology 

CT is usually superior in demonstration of their size and 

their extent 

MRI is particularly helpful to evaluate bleeding in an 

intrahepatic cysts and to rattach cysts to bilary tree.

PURPOSE 

Describe and illustrate radiologic findings in a variety of 

cystic focal liver lesions 

Produce an education electronic exhibit

METHODS AND MATERIALS

METHODS AND MATERIALS 

Diaporama of numeric images (ultra-sonography, CT, MRI 

and CPMRI) for illustrating cases. 

Cystic liver lesions in our study include simple cyst, 

autosomal dominant polycystic liver disease, Caroli 

disease, biliary cystadenoma, cystic metastases, pyogenic 

and fungal abscesses, intrahepatic simple and complicated 

hydatid cyst and biloma.

ILLUSTRATIONS AND 

COMMENTARY

HEPATIC CYST

HEPATIC CYST 

Simple hepatic cysts are benign developmental lesions that 

do not communicate with the biliary tree. 

The current theory regarding the origin of true hepatic cysts 

is that they originate from hamartomatous tissue. 

Hepatic cysts are common and are presumed to be present 

in 2.5% of the population [1]. They are more often 

discovered in women and are almost always asymptomatic.

HEPATIC CYST 

Simple hepatic cysts can be solitary or multiple, with 

the latter being the more typical scenario. 

At histopathologic analysis, true hepatic cysts contain 

serous fluid and are lined by a nearly imperceptible 

wall consisting of cuboidal epithelium, identical to that 

of bile ducts, and a thin underlying rim of fibrous 

stroma.

HEPATIC CYST 

IMAGING PATTERN 

Sonographic criteria [2]: 

–Focal liver lesion with anechoic contents. 

–Thin walls not distinguishable from the adjacent liver tissue. 

–Posterior acoustic enhancement. 

On CT [1]: 

-Nonenhanced CT scans, a hepatic cyst appears as a homogeneous 

and hypoattenuating lesion on. 

-No enhancement of its wall or content after intravenous 

administration of contrast material. 

-It is typically round or ovoid and well-defined.

HEPATIC CYST 

IMAGING PATTERN 

At MR imaging [1]: 

– Homogeneous very low signal intensity on T1W images and 

homogeneous very high signal intensity on T2W images. 

– Owing to their fluid content, an increase in signal intensity is 

seen on heavily T2-weighted images. 

– This increase allows differentiation of these lesions from 

metastatic disease. 

– No enhancement is seen after administration of gadolinium 

chelates. 

– In cases of intracystic hemorrhage, a rare complication in simple 

hepatic cysts, the signal intensity is high, with a fluid-fluid level, 

on both T1 and T2-W images when mixed blood products are 

present.

US and MR images of biliary cysts

POLYCYSTIC LIVER DISEASE

32 year old patient, episodic abdominal pain 

Medical history: a father followed for polycystic disease 

Abdominal ultrasonography showed multiple simple cystic lesions 

located in the liver and the kidneys

POLYCYSTIC LIVER DISEASE 

DISCUSSION 

Usually, patients with autosomal dominant polycystic liver 

disease are asymptomatic and liver dysfunction occurs 

only sporadically. 

However, advanced disease can result in hepatomegaly, 

liver failure, or Budd-Chiari syndrome. 

In these more severe cases, percutaneous interventional 

alcohol ablation has been useful as an alternative to partial 

liver resection or even transplantation.


DISCUSSION 

Hepatic cysts can also be part of polycystic liver disease, an 

autosomal dominant disorder often found in association with 

renal polycystic disease. 

Although hepatic cysts are found in 40% of cases of autosomal 

dominant polycystic disease involving the kidneys, they may be 

seen without identifiable renal involvement at radiography [3].


DISCUSSION 

The diagnosis is easily obtained in ultrasonography by the 

description of multiple cystic lesions which have the 

characteristics of simple cysts: focal liver lesion with 

anechoic contents, thin walls not distinguishable from the 

adjacent liver tissue, posterior acoustic enhancement. 

When the number of cysts is very important, there is a loss 

of the internal architecture of the liver, and the 

visualization of the vessels and anatomical structures can 

be very difficult.


DISCUSSION 

Polycystic liver disease typically appears as multiple 

homogeneous and hypoattenuating cystic lesions with a 

regular outline on nonenhanced CT scans, with no wall or 

content enhancement on contrast-enhanced images.


DISCUSSION 

At MR imaging [2], hepatic cysts in polycystic liver 

disease have very low signal intensity on T1-weighted 

images and do not enhance after administration of 

gadolinium contrast material. 

Owing to their pure fluid content, homogeneous high 

signal intensity is demonstrated on T2-weighted and 

heavily T2-weighted images. 

In patients with polycystic liver disease, signal intensity 

abnormalities indicating intracystic hemorrhage are more 

frequently encountered than in cases of simple hepatic 

cysts due to the great number of cysts.

CAROLI DISEASE

A 50 year-old man, hepatalgy with on ultrasound dialatation of intrahepatic 

biliary ducts and biliary cysts 

 

MRI and MR cholangiogram 

showed saccular dilatation of 

the biliary tree (→) with 

enhancement of central portal 

vein radicals () the central 

“dot sign” 

→

Other case of caroli disease associating bilary cysts communicating 

with dilated biliary ducts

CAROLI DISEASE 

DISCUSSION 

Congenital communicating cavernous ectasia of the biliary 

tract, is a rare, autosomal recessive developmental 

abnormality. 

Characterized by saccular dilatation of the intrahepatic bile 

ducts, multiple intrahepatic calculi, and associated cystic 

renal disease. 

Two forms of Caroli : 

– a less common pure form (type 1) 

– a more complex form (type 2), associated with other 

ductal plate abnormalities, such as hepatic fibrosis.


DISCUSSION 

The abnormality may be segmental or diffuse. 

Clinical symptoms are usually restricted to recurrent 

attacks of right upper quadrant pain, fever, and, more 

rarely, jaundice. 

The prevalence of cholangiocarcinoma is higher in patients 

with this disease than in the general population.


DISCUSSION 

CT typically shows: 

– Hypoattenuating dilated cystic structures of varying 

size that communicate with the biliary tree. 

– The presence of tiny dots with strong contrast 

enhancement within the dilated intrahepatic bile ducts 

(the “central dot” sign) is considered very suggestive of 

Caroli disease. 

– At histopathologic analysis, these intraluminal dots 

correspond to intraluminal portal vein radicals.


DISCUSSION 

At MR imaging, the dilated and cystic biliary system 

appears hypointense on T1-weighted images and markedly 

hyperintense on T2-weighted images. 

After intravenous administration of gadolinium contrast 

material, the intraluminal portal vein radicals strongly 

enhance [3].


DISCUSSION 

This appearance is consistent with the wall of an 

insufficiently resorbed, malformed ductal plate that 

surrounds the portal vein radicals. 

In the absence of the central dot sign, MR cholangiography 

can be extremely valuable in diagnosis of Caroli disease by 

demonstrating the pathognomonic feature of saccular 

dilated and nonobstructed intrahepatic bile ducts that 

communicate with the biliary tree.

LIVER ABSCESSES

LIVER ABSCESSES 

A 60 year old female patient 

Left lower quadrant pain, fever, and leukocytosis 

Abdominal enhanced CT showed a sigmoid diverticulitis and cystic 

liver lesion with high attenuation of the surrounding normal liver 

parenchyma due to hyperemia (the double target sign) with partial 

phlebitis of the left portal ramus ( ).

•30 year-old patient followed for Thoracic actinomycosis 

Ultrasonography showed multiple cystic mass of the liver: Actinomycosic 

Abcesses

Hepatic tuberculosis : miliary form : multiple small granulomas giving rise the 

« bright » pattern of the liver

Liver Abcess Enhanced 

52 year-old patient 

Fever and abdominal pain 

Gas-containing pyogenic abscess in the left lobe of the liver.


DISCUSSION 

Abscesses can be classified as pyogenic, amebic, or fungal. 

Ascending cholangitis and portal phlebitis are the most 

frequent causes of pyogenic hepatic abscesses. 

Clinical symptoms of abscesses are related to the 

coexistence of sepsis and the presence of one or more 

space-occupying lesions


DISCUSSION 

Pyogenic abscesses may be classified as either 

microabscesses (


DISCUSSION 

At contrast-enhanced CT, large abscesses are generally 

well defined and hypoattenuating. 

they may be unilocular with smooth margins or complex 

with internal septa and an irregular contour. 

Rim enhancement is relatively uncommon, as is the 

presence of gas.


DISCUSSION 

At MR imaging, pyogenic abscesses have variable signal 

intensity on T1- and T2-weighted images, depending on 

their protein content. 

Perilesional edema, characterized by subtly increased 

signal intensity, can be seen on T2-weighted MR images 

[4].

HYDATID DISEASE

23 year old patient 

Abdominal pain 

HYDATID DISEASE 

Abdominal ultrasonography 

showed a large Liver cyst 

with characteristic thickening 

of its wall ()



Abdominal sonography 

showed a fluid collection 

with a split wall ().



Fluid collection with septa: 

Multivesicular cyst with 

daughter vesicles of 

different sizes and having 

well-defined borders.



Recurrent abdominal pain 

Formation not well limited, 

with irregular hyperechoic 

solid pattern and 

hypoechoic structures.



Systematic abdominal 

ultrasonography: Aspect of 

arciform thick line, with 

posterior cone-shaped 

shadow.



Fever, cough and abdominal pain 

US and enhanced CT showed a large cystic mass in 

communication with a loculated pleural collection: 

Transdiaphragmatic thoracic involvement

a b 

c d 

Images of simple hydatic cysts type I (a) and Type IV (b, c, d) on CT


A 32 year old patient presenting 

a fever, abdominal pain and 

jaundice. 

Computed tomography showed 

a high-attenuation material 

passing through the cyst wall 

defect and filling the biliary 

radicles or common bile duct.


DISCUSSION 

Hepatic echinococcosis is an endemic disease in the 

Mediterranean basin and other sheep-raising countries. 

Humans become infected by ingestion of eggs of the 

tapeworm Echinococcus granulosus, either by eating 

contaminated food or from contact with dogs. 

The ingested embryos invade the intestinal mucosal wall 

and proceed to the liver by entering the portal venous 

system. 

Although the liver filters most of these embryos, those that 

are not destroyed then become hepatic hydatid cysts.


DISCUSSION 

At histopathologic analysis, a hydatid cyst is composed of 

three layers: 

– the outer pericyst, which corresponds to compressed 

liver tissue 

– the endocyst, an inner germinal layer 

– the ectocyst, a translucent thin interleaved membrane 

Maturation of a cyst is characterized by the development of 

daughter cysts in the periphery as a result of endocyst 

invagination.


DISCUSSION 

Ultrasonography, a noninvasive, readily available, 

sensitive, and cost-effective imaging technique, should be 

the diagnostic method of choice 

US is a useful diagnostic tool to visualize the location, 

number, internal structure of the cysts and the associated 

complications. 

Besides, it is the most sensitive modality to detect the 

hydatid sand, septae and membranes in the cysts. 

The specificity of US is around 90% [5].


DISCUSSION 

The US images of the hydatid cyst may vary according to 

his developmental stage. 

Gharbi et al. [5] had classified hydatid cyst into 5 types 

based on cyst appearance: 

– Type I: Pure Fluid Collection 

– Type II: Fluid Collection with a Split Wall 

– Type III: Fluid Collection with Septa 

– Type IV: Heterogeneous Echo Patterns 

– Type V: Reflecting Thick Walls


DISCUSSION 

At CT, a hydatid cyst usually appears as a well-defined 

hypoattenuating lesion with a distinguishable wall [3]. 

Coarse calcifications of the wall are present in 50% of 

cases [3]. 

Daughter cysts are identified in approximately 75% of 

patients [3].


DISCUSSION 

MR imaging clearly demonstrates the pericyst, the matrix, 

and daughter cysts. 

The pericyst is seen as a hypointense rim on both T1- and 

T2-weighted images because of its fibrous composition 

and the presence of calcifications. 

The hydatid matrix (hydatid “sand”) appears hypointense 

on T1-weighted images and markedly hyperintense on T2weighted 

images. 

When present, daughter cysts are more hypointense than 

the matrix on T2-weighted images.

Some MRI aspects of hydatid cyst


DISCUSSION 

Hydatid disease primarily affects the liver and typically 

demonstrates well-known, characteristic imaging findings. 

However, there are many potential local complications: 

– Transdiaphragmatic thoracic involvement 

– Perforation into hollow viscera 

– Peritoneal seeding 

– Biliary communication 

– Portal vein involvement 

– Abdominal wall invasion


DISCUSSION 

Biliary communication: 

– Communicating rupture of a cyst into the biliary system 

may occur through small fissures or bile-cyst fistulas or 

through a wide perforation that allows access to a main 

biliary branch. 

– The only direct sign of rupture into the biliary tree is 

the visualization of the cyst wall defect or of a 

communication between the cyst and a biliary radicle.


DISCUSSION 


– US demonstrates anechoic, rounded or echogenic linear 

structures without posterior acoustic shadowing in the 

biliary tract. 

– CT can demonstrate high-attenuation material passing 

through the cyst wall defect and filling the biliary 

radicles or common bile duct. 

– CT is superior to US in depicting hydatid cyst contents 

in the distal segment of the common bile duct.


DISCUSSION 


– Indirect signs of biliary communication include 

increased echogenicity at US and fluid levels and signal 

intensity changes at MR imaging. 

– An air-fluid level within the cyst, previously described 

as a sign of infection, is considered to be a sign either 

of rupture into the biliary tree or a hollow viscus or of a 

bronchopleural fistula. 

– Lipid material that forms a fat-fluid level within the 

cyst has also been described as an indirect sign of 

biliary communication.


DISCUSSION 

Infection : 

– CT is the modality of choice for demonstrating cyst 

infection. 

– Contrast-enhanced CT may reveal the typical highattenuation 

rim representing abscesses surrounding the 

lesion. 

– CT also most clearly depicts gas or air-fluid levels 

within the cyst.


DISCUSSION 

Peritoneal Seeding: 

– Peritoneal echinococcosis is almost always secondary 

to hepatic disease, although some unusual cases of 

primary peritoneal involvement have been described. 

– Most of these cases are related to previous surgery for 

hepatic disease.


DISCUSSION 

Peritoneal Seeding: 

– CT is the modality of choice in affected patients 

because it allows imaging of the entire abdomen and 

pelvis. 

– Cysts may be multiple and located anywhere in the 

peritoneal cavity. 

– Peritoneal hydatid disease may grow and occupy the 

entire peritoneal cavity, simulating a multiloculated 

mass.

HEPATIC CYSTADENOMA

HEPATIC CYSTADENOMA 

32 year old patient presenting an abdominal pain 

Echography and CT showed a dysmorphic liver with a cystic 

multiloculated mass with mural nodules on the right hepatic lobe.


DISCUSSION 

Biliary cystadenomas are rare, usually slow growing, multilocular 

cystic tumors that represent less than 5% of intrahepatic cystic masses 

of biliary origin [6]. 

They occur predominantly in middle-aged women (mean age, 38 

years) and are considered premalignant lesions. 

Symptoms are usually related to the mass effect of the lesion and 

consist of intermittent pain or biliary obstruction [6]. 

At microscopy, a single layer of mucin-secreting cells lines the cyst 

wall. The fluid within the tumor can be proteinaceous, mucinous, and 

occasionally gelatinous, purulent, or hemorrhagic due to trauma [6].


DISCUSSION 

Cystadenoma is seen in the US as multiloculated liver mass. 

At CT, it appears as a solitary cystic mass with a well-defined 

thick fibrous capsule, mural nodules, internal septa, and rarely 

capsular calcification. 

The MR imaging characteristics of an uncomplicated biliary 

cystadenoma correlate well with the pathologic features: The 

appearance of the content is typical for a fluid-containing 

multilocular mass, with homogeneous low signal intensity on 

T1-weighted images and homogeneous high signal intensity on 

T2-weighted images.

BILOMA

49 year-old women, 

surgery for cholecystic lithiasis 2 years ago. 

Admitted for exploration of cystic mass of the liver. 

Enhanced CT showed cystic mass of the segment 

IV with a compression of the bilary bifurcation and 

dilatation of right bilary tree. 

Surgical findings: biloma.

BILOMA 

DISCUSSION 

Bilomas result from rupture of the biliary system, which 

can be spontaneous, traumatic, or iatrogenic following 

surgery or interventional procedures. 

Extravasation of bile into the liver parenchyma generates 

an intense inflammatory reaction, there by inducing 

formation of a well-defined pseudocapsule.

BILOMA 

DISCUSSION 

At both CT and MR imaging, a biloma usually appears as a 

well-defined or slightly irregular cystic mass without septa 

or calcifications [3]. 

Also, the pseudocapsule is usually not readily identifiable. 

This imaging appearance, in combination with the clinical 

history and location, should enable correct diagnosis.

CYSTIC METASTASES

CYSTIC METASTASES 

A 52 year-old patient followed for colic cancer. 

Enhanced CT showed multiple pseudo cystic mass 

dispread through the liver.

CYSTIC METASTASES 

DISCUSSION 

Most hepatic metastases are solid, but some have a 

complete or partially cystic appearance [3]. 

In general, two different pathologic mechanisms can 

explain the cystlike appearance of hepatic metastases. 

First, hypervascular metastatic tumors with rapid growth 

may lead to necrosis and cystic degeneration. This 

mechanism is frequently demonstrated in metastases from 

neuroendocrine tumors, sarcoma, melanoma, and certain 

subtypes of lung and breast carcinoma. 

Second, cystic metastases may also be seen with mucinous 

adenocarcinomas, such as colorectal or ovarian carcinoma.

CONCLUSION

CONCLUSION 

Characterization of cystic focal liver lesions has always 

been a challenge for the radiologist. 

However, due to refined and new imaging techniques, in 

most cases a correct presumptive diagnosis can be made on 

the basis of imaging criteria alone.

REFERENCES 

1. Mathieu D, Vilgrain V,Mahfouz A, et al. Benign liver tumors. Magn Reson 

Imaging Clin N Am 1997; 5:255–288. 

2. Richard M. Spiegel, Donald L. King, and William M. Ultrasonography of 

Primary Cysts of the Liver. Am J Rontgnol 131:235-238, August 1978. 

3. Koenraad J, Mortele, Pablo R. Ros. Cystic Focal Liver Lesions in the Adult: 

Differential CT and MR Imaging Features. RadioGraphics 2001; 21:895– 

910. 

4. K J. Mortele ,E Segatto, P R Ros. The Infected Liver: Radiologic-Pathologic 

Correlation. RadioGraphics 2004; 24:937–955. 

5. Gharbi HA, Hassine W, Brauner MW, Dupuch KD. Ultrasound examination 

of the hydatic liver. Radiology 1981; 139:459–463. 

6. B Ihn Choi and al. Biliary Cystadenoma and Cystadenocarcinoma: CT and 

Sonographic Findings. Radiology 1989; 171:57-61

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