Gallstone ileus is an uncommon cause of a mechanical small bowel obstruction. It is a rare complication of chronic cholecystitis 7 and occurs when a gallstone passes through a fistula between the gallbladder and small bowel before becoming impacted at the ileocaecal valve.
Gadoxetate disodium (also known by the tradenames PrimovistTM and EovistTM) is a hepatospecific paramagnetic gadolinium-based contrast agent, used exclusively in MRI liver imaging. Its chief use is in hepatic lesion characterisation, i.e. assessing focal liver lesions identified on other imaging...
Splenic infarction is a result of ischaemia to the spleen, and in many cases requires no treatment. However, identification of the cause of infarction is essential.
Splenic infarcts can occur due to a number processes, involving either arterial supply, the spleen itself and the ...
Hepatic abscesses, like abscesses elsewhere, are localised collections of necrotic inflammatory tissue caused by bacterial, parasitic or fungal agents.
The frequency of individual infective agents as causes of liver abscesses are intimately linked to the demographics of the affec...
Diffuse thickening of the gallbladder wall can occur in a number of situations.
gallbladder empyema 7
postprandial physiological state (pseudothickening)
Staging of pancreatic ductal adenocarcinoma is traditionally done according to American Joint Committee on Cancer (AJCC) / Union for International Cancer Control (IUCC) TNM system. As of 2010 (7th edition AJCC), both exocrine and endocrine tumours of the pancreas are now staged using the same s...
Alpha-1 antitrypsin (A1AT) deficiency is a hereditary metabolic disorder and is the most common genetic cause of emphysema and metabolic liver disease in children. It results in the unopposed action of neutrophil elastase and subsequent severe basal pan lobular emphysema and respiratory symptoms...
Glucagonomas are pancreatic endocrine tumours that secrete glucagon. Most lesions are malignant.
They are very rare with an incidence of ~0.000005% or less than 1 case per 20 million. Equal incidence in middle-aged men and women.
Most patients present with...
Technetium agents based on the technetium-99m (Tc-99m) radioisotope are frequently used agents in medical imaging. The radioactive technetium radiotracer can be chelated to a number of different compounds to create specific radiopharmaceuticals and optimise the functional imaging of various stru...
This article lists examples of normal imaging of the liver and biliary tree and surrounding structures, divided by region and modality.
liver silhouette: example
example 1 with shear wave elastography
liver Doppler ultrasound: example ne...
Examination of the liver with MRI requires numerous sequences and imaging at multiple times after the administration of gadolinium. Many variations exist, but a typical protocol would include:
T2 fat sat
T1 weighted gradient echo in and out of phase
T1 2D or 3D gradient ech...
Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive imaging technique to visualize intra and extrahepatic biliary tree and pancreatic ductal system.
It can provide the diagnostic range equivalent to the ERCP and so it can replace the ERCP in high risk patient to avoid significa...
Ventriculogallbladder shunts are a rare form of cerebrospinal fluid diversion, used when a ventriculoperitoneal shunt is not possible (e.g. intra-abdominal adhesions, peritonitis).
a ventriculoperitoneal shunt in a right upper quadrant CSFoma
Portal hypertension is defined as portal venous pressure greater than 12 mmHg.
Causes can be split in their relation to the hepatic sinusoids:
portal vein thrombosis
extrinsic compression of portal vein
Schistosomiasis (S. mansoni or S. japonicum)
Various channels that collect bile from the hepatic parenchyma and transport it to the duodenum constitute the biliary tree.
By convention the biliary tree is divided into intra- and extra-hepatic bile ducts 1. There is significant variation in the biliary tree with the classical...
Abdominal and pelvic anatomy encompasses the anatomy of all structures of the abdominal and pelvic cavities.
This anatomy section promotes the use of the Terminologia Anatomica, the global standard for correct gross anatomical nomenclature.
Infiltrative hepatocellular carcinoma, also known as diffuse hepatocellular carcinoma (HCC), is an infrequent subtype of HCC, which has particular imaging characteristics. Because of these characteristics, it has been called cirrhotomimetic-HCC or cirrhosis-like HCC.
The differential for cystic lesions of the pancreas includes:
intraductal papillary mucinous neoplasms (IPMN)
serous cystadenoma uncommonly uni/macrolocular
pancreatic cysts occur in association with
von Hippel Lindau syndrome
autosomal dominant polycysti...
Secondary hepatic involvement with lymphoma (secondary hepatic lymphoma) is common, much more so than primary hepatic lymphoma.
Hepatomegaly with deranged liver function tests is the most common presentation. Jaundice is common. Rarely, patients may present with acute li...
Scleroderma, also known as systemic sclerosis, is an autoimmune connective tissue disorder characterised by multisystem fibrosis and soft tissue calcification. As such, it affects many separate organ systems, which are discussed separately:
musculoskeletal manifestations of scleroderma
Schistosomiasis hepatic manifestations are a chronic result of the deposition of eggs into small portal venules leading to periportal fibrosis and liver cirrhosis.
For a general view over this trematode infection, please refer to the main article on schistosomiasis.
Schistosomiasis (also referred to as bilharzia or snail fever) is the result of infection by blood fluke (trematode worm) of the Schistosoma species.
Schistosomiasis is very common, affecting over 200 million people, with the vast majority (85%) in Africa. It is prevalent in tropi...
Sarcoidosis is a systemic inflammatory disease of unknown origin characterized by the formation of non-caseating granulomas. Virtually any organ system may be involved. Although the involvement of abdominal viscera is less frequent than pulmonary and mediastinal disease when it occurs, it may m...
Spindle cell hepatocellular carcinoma, also called sarcomatoid hepatocellular carcinoma, is a rare variant of hepatocellular carcinoma (HCC). These patients are reported to have low or normal AFP levels, otherwise risk factors and clinical presentation are similar to typical hepatocellular carci...
Splenic hamartomas are very rare and usually solitary although may be present as multiple nodules present in tuberous sclerosis or Wiskott-Aldrich syndrome.
The only recently described entity sclerosing angiomatoid nodular transformation (SANT) of the spleen, a non-neoplastic vascular entity de...
Intraductal papillary mucinous neoplasms or tumours (IPMNs or IMPTs) are cystic tumours of the pancreas.
These tumours are most frequently identified in older patients (50-60 years of age) 6, and thus are sometimes colloquially referred to as the "grandfather lesion". Main duct ty...
Simple hepatic cysts are common benign liver lesions and have no malignant potential. They can be diagnosed on ultrasound, CT, or MRI.
Simple hepatic cysts are one of the commonest liver lesions, occurring in ~2-7% of the population 1,2. There may be a slight female predilection.
Primary biliary cholangitis (PBC) is a chronic progressive cholestatic liver disease that is the cause of 1-2% of deaths from cirrhosis and constitutes the third most common indication for liver transplantation in adults.
The name of this disease was changed from primary biliary ci...
Primary hyperoxaluria, also referred as primary oxalosis, is a congenital autosomal recessive disease related to a liver enzyme deficiency leading to massive cortical nephrocalcinosis and renal failure.
Please, refer on secondary oxalosis for a discussion on the acquired form of hyperoxaluria....
Primary hepatic lymphoma (PHL) is rare accounting for roughly 100 described cases. If it is being considered as a diagnosis, distal lymphadenopathy, splenomegaly, bone marrow disease, and leukaemia should not be present for at least 6 months after the liver tumour is detected (see: secondary hep...
Portal venous gas is the accumulation of gas in the portal vein and its branches. It needs to be distinguished from pneumobilia, although this is usually not too problematic, when associated findings are taken into account along with the pattern of gas (i.e. peripheral in portal venous gas, cent...
Serous cystadenoma of the pancreas (or microcystic adenoma) is an uncommon type of benign cystic pancreatic neoplasm.
There is a recognised strong female predilection (M:F ~ 1:4) and usually presents in middle age to elderly patients (>60 years of age).
Focal gallbladder wall thickening is an imaging finding that includes both benign and malignant etiologies.
gallbladder carcinoma: look for infiltration into adjacent organs, metastases, lymphadenopathy, bile duct dil...
Sickle cell disease (SCD) is a hereditary (autosomal recessive) condition resulting in the formation of abnormal haemoglobin (a haemoglobinopathy), which manifests as multisystem ischaemia and infarction, as well as haemolytic anaemia.
There is no recognised gender predilection. ...
Ultrasound guided biopsy is one form of image guided biopsy, typically performed by a radiologist. It is the most common form of image guided biopsy, offering convenience and real time dynamic observation with echogenic markers on cannulae allowing for precise placement.
It can potentially be ...
Hepatitis C virus (HCV) is an RNA virus and a member of the Flaviviridae family. It is a risk factor for the development of hepatocellular carcinoma (HCC).
Route of transmission
The most common route of transmission is through blood products and contaminated needles. Unprotected sex...
Portopulmonary hypertension (POPH/PPHTN) refers to pulmonary artery hypertension that develops in the setting of portal hypertension (with or without underlying liver disease). It falls under group 1.4 of the Dana point 2008 pulmonary hypertension classification system.
Hepatitis B virus (HBV) is a circular DNA virus endemic in many parts of the world. It is a risk factor for the development of hepatocellular carcinoma (HCC).
Acute HBV infection is most often subclinical and asymptomatic. Symptomatic patients (~33%) may experience fever,...
Polyarteritis nodosa (PAN) is a systemic inflammatory necrotising vasculitis that involves small to medium sized arteries (larger than arterioles).
Polyarteritis nodosa (PAN) is commoner in males and typically presents around the 5th to 7th decades. Twenty to thirty percent of p...
Post-transplant lymphoproliferative disorder (PTLD), also referred as post-transplant lymphoproliferation disorder, represents a variety of conditions ranging from lymphoid hyperplasia to malignancy, included in the 2008 WHO classification of tumours of haematopoietic and lymphoid tissues. It ca...
The wheel within a wheel sign describes one of several possible ultrasound findings of hepatic candidiasis. The finding consists of a round lesion with three layers corresponding to the following histopathological changes 2:
peripheral hypoechoic area (fibrosis)
middle hyperechoic area (inflam...
The Couinaud classification (pronounced kwee-NO) is currently the most widely used system to describe functional liver anatomy. It is the preferred anatomy classification system as it divides the liver into eight independent functional units (termed segments) rather than relying on the tradition...
Passive hepatic congestion, also known as congested liver in cardiac disease, describes the stasis of blood in the hepatic parenchyma, due to impaired hepatic venous drainage, which leads to dilation of central hepatic veins and hepatomegaly.
Passive hepatic congestion is a well-studied result...
Pancreatic intraepithelial neoplasia (PanIN) is a precursor lesion to pancreatic ductal adenocarcinoma, but the frequency at which this transition occurs is unknown.
Increasing incidence with age 1. Risk factors:
pancreatic lipomatosis 3
Mostly flat lesions ...
Paraduodenal pancreatitis is an uncommon type of focal chronic pancreatitis affecting the groove between the head of the pancreas, the duodenum and the common bile duct.
The following entities with which it shares clinicopathological features are unified by this term and should no ...
Pancreatoblastomas are rare paediatric tumours of the pancreas. However, they are the most common pancreatic neoplasm of childhood and are often associated with a raised alpha-fetoprotein.
There is slight male predilection. Usually occurs in the first decade of life with a mean ag...
Pancreatic lymphoma is most commonly a B-cell sub-type of non-Hodgkin lymphoma.
Typically seen in middle-aged patients: mean of 55 years; range, 35-75 years and in immunocompromised patients.
Presentation is often non-specific. reported symptoms include 1:
The pancreas is uncommonly injured in blunt trauma. However, pancreatic trauma has a high morbidity and mortality. Imaging features range from subtle to obvious.
The pancreas is injured in ~7.5% (range 2-13%) of blunt trauma cases 1,3. Motor vehicle accidents account for the vast ...
Pancreatic pseudocysts are common sequelae of acute pancreatitis or chronic pancreatitis, and the most common cystic lesion of the pancreas. They are important both in terms of management and differentiation from other cystic processes or masses in this region.
The following are th...
Pancreatic lipomatosis refers to the fatty replacement of pancreatic parenchyma. This finding is most often associated with obesity and ageing.
It tends to be commonest pathological condition involving the pancreas. The condition may occasionally simulate a mass like lesion particularly when f...
Hepatic angiomyolipoma (AML) is an uncommon benign hamartomatous hepatic mass lesion, containing blood vessel (angioid), smooth muscle (myoid) and mature fat (lipoid) components. There is an association with tuberous sclerosis, although this is less strong than for renal AMLs.
Hepatic metastases are 18-40 times more common than primary liver tumours 6. Ultrasound, CT, and MRI are all useful for detection of hepatic metastases and evaluation across multiple postcontrast CT series, or MRI pulse sequences are necessary. The most common sites of primary malignancy that me...
Limy bile stands for the presence of a viscous substance in the dependent parts of the gallbladder and/or bile ducts, almost entirely composed of calcium carbonate, and therefore highly radiopaque.
The terms limy bile and calcium milk gallbladder can be used interchangeably for inc...
Hepatoblastoma is the most common primary malignant liver tumour in children under four years of age who usually present with painless abdominal mass and raised AFP. It is tumour of embryonic origin.
Most cases are seen during the first 18 months of life and diagnosis in adulthood...
Focal nodular hyperplasia (FNH) is a regenerative mass lesion of the liver and the second most common benign liver lesion (most common is a haemangioma). Many FNHs have characteristic radiographic features in multimodality imaging, but some lesions may be atypical in appearance. FNHs are typical...
Rhabdomyosarcomas of the biliary tract are rare tumours, usually identified in children, with a very poor prognosis. They are usually grouped under botryoid rhabdomyosarcomas.
For a general discussion of this type of tumour, please refer to the article on rhabdomyosarcomas.
Mastocytosis is a disorder of excessive mast cell proliferation, which is now classified as a myeloproliferative neoplasm. Two clinical entities fall under the mastocytosis umbrella: cutaneous (urticaria pigmentosa) and systemic mastocytosis (with or without cutaneous manifestations). The articl...
Splenic hydatid infection is a rare form of hydatid disease, and isolated splenic involvement is even less common.
For a general discussion, and for links to other system specific manifestations, please refer to the article on hydatid disease.
Splenic hydatid disease has been re...
Hepatic hydatid disease is a parasitic zoonosis caused by the Echinococcus tapeworm. In the liver, two agents are recognised as causing disease in the human:
For a general discussion, and for links to other system specific manifestations, p...
Acute hepatitis occurs when the liver suffers an injury with a resulting inflammatory reaction. The cause of the injury can happen in multiple different ways, and imaging findings are often non-specific. Ultrasound and MRI may be useful imaging modalities to suggest the diagnosis, but often the ...
Acute liver failure (ALF), also known as fulminant hepatic failure, refers to sudden severe liver dysfunction from injury without underlying chronic liver disease (CLD), although sometimes it presents as decompensation of an unknown CLD.
ALF is rare, with < 1 case per 100,000 in ...
Jaundice refers to a clinical sign of hyperbilirubinemia (>2.5 mg/dl) which has many causes. It is often a clue to a diagnosis. It can be largely divided into two types:
non-obstructive, i.e. pre-hepatic and hepatic causes
obstructive, i.e. post-hepatic causes
Imaging has a major role in dete...
Interstitial oedematous pancreatitis is one of the two subtypes of acute pancreatitis. It is normally referred to as "acute pancreatitis" or "uncomplicated pancreatitis" in day-to-day use. Please refer to the article on acute pancreatitis for further details.
Inflammatory myofibroblastic tumours (IMT), also known as plasma cell granulomas, are rare neoplasms that have a diverse spectrum of biological behaviour.
They can occur at any age and there is currently no recognised gender predilection.
Composed of spindle cells (ke...
Hepatisation of the gallbladder is a sonographic entity in which the gallbladder lumen is entirely filled with tumefactive sludge giving the gallbladder a similar appearance to liver parenchyma. It is one of the causes of non-visualisation of the gallbladder on sonography.
In the set...
Inferior vena cava (IVC) webs are an uncommon condition characterised by obstruction of the hepatic segment of the inferior vena cava by a membrane or fibrous band. This is often associated with occlusion of one or more of the hepatic veins.
If there is hepatic vein invol...
Insulinomas are the most common sporadic endocrine tumour of the pancreas.
Account for 40% of syndromic pancreatic endocrine tumours. Overall incidence of ~0.0003%.
Typically insulinomas present with Whipple's triad consisting of:
fasting hypoglycaemia (<5...
Extrapulmonary tuberculosis (TB) refers to the haematogenous spread of Mycobacterium tuberculosis.
Extrapulmonary tubercuosis can occur as a primary form of the disease, i.e. direct infection of an extrapulmonary organ without the presence of primary pulmonary tuberculosis or it can ...
Budd-Chiari syndrome refers to the clinical picture that occurs when there is partial or complete hepatic venous outflow obstruction. It is characterised on imaging by ascites, caudate hypertrophy, peripheral atrophy, and prominent collateral veins.
Budd-Chiari syndrome is rare. ...
Pneumobilia, also known as aerobilia, is the accumulation of gas in the biliary tree. It is important to distinguish pneumobilia from portal venous gas, the other type of branching hepatic gas. There are many causes of pneumobilia and clinical context is often important to distinguish between th...
Inflammatory hepatic adenomas are a genetic and pathological subtype of hepatic adenoma. Their appearance and prognosis is different than other subtypes and has the highest incidence of haemorrhage amongst hepatic adenoma subtypes.
Most common subtype of hepatic adenoma (40-50%). ...
Infantile hepatic haemangiomas (IHH) are a liver lesion composed of large endothelial-lined vascular channels seen in fetuses and neonates. It should not be confused with a hepatic epithelioid haemangioendothelioma, which occurs in older patients.
Those benign tumours were previous...
Nonalcoholic fatty liver disease (NAFLD) occurs when fat is deposited into hepatocytes without a known cause (such as with alcoholic fatty liver disease). The deposition of fat may lead to hepatic inflammation (hepatitis) and may eventually lead to cirrhosis.
"Nonalcoholic fatty li...
Myelofibrosis is a haematological disorder where there is the replacement of bone marrow with collagenous connective tissue and progressive fibrosis. It is also classified as a myeloproliferative disorder. It is characterised by:
extramedullary hematopoiesis (EMH)
Hepatic carcinosarcoma is a very rare tumour that is defined by mixed histological features.
This tumour has also been referred to as malignant mixed tumour, spindle cell carcinoma, pseudosarcoma or sarcomatoid carcinoma 1,2.
Hepatic carcinocarcinoma contain a mixture...
Pseudopancreatitis refers to the presence of fluid in or around the pancreas in the setting of trauma but in the absence of direct signs of traumatic pancreatic injury. Most patients will have a normal serum lipase level, but amylase has a limited sensitivity and specificity for pancreatic traum...
HNF 1 alpha mutated hepatic adenomas are a genetic and pathologic subtype of hepatic adenoma. Their appearance and prognosis are different than other subtypes.
They are the second most common (30-35%) hepatic adenoma, after the inflammatory subtype. They occur only in female patie...
Hereditary haemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is a rare inherited disorder characterised by abnormal blood vessel formation in the skin, mucous membranes, and organs including the lungs, liver, and central nervous system.
Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a condition arising from occlusion of hepatic venules.
right upper quadrant pain
abnormal liver function tests
Toxic injury to liver s...
Hepatic encephalopathy (also known as portosystemic encephalopathy) refers to a spectrum of neuropsychiatric abnormalities occurring in patients with liver dysfunction and portal hypertension. It results from exposure of the brain to excessive amounts of ammonia.
Primary hepatic carcinoid is an extremely rare type of carcinoid tumour, with somewhere between 60-90 cases reported in the literature. Metastatic carcinoid tumour from the gastrointestinal tract to the liver is far more common.
Some patients present with carcinoid syndro...
Hepatic angiosarcoma is a rare malignancy but is still the third most common primary liver tumour. They have a variable appearance on both CT and MRI reflecting the pleomorphic histological nature. Prognosis is very poor, with survival uncommon beyond one year from diagnosis.
Hereditary pancreatitis is a rare subtype of chronic pancreatitis that has an autosomal dominant inheritance. Imaging plays a role in excluding underlying abnormalities.
As a congenital condition, presentation with acute pancreatitis attacks typically occurs in childhood,...
Hepatic solitary fibrous tumours (hepatic SFTs) are rare mesenchymal tumours.
Fewer than 60 cases have been reported in the literature. Female predominance (~70%). There is a mean age of 52 years at presentation, but a wide range of incidence (16-84 years).
Hepatic mesenchymal hamartoma is an uncommon benign hepatic tumour. Some authors even consider this to be a developmental anomaly rather than a cystic neoplasm 9,12.
It typically occurs in children and neonates, with most cases presenting within the first two years of life 3. Ther...
Hepatic lymphoma is a rather broad term given to any form of hepatic involvement with lymphoma. This can be broadly divided into:
secondary hepatic involvement with lymphoma: most common by far, many tend to be non-Hodgkin lymphoma (NHL) 1
primary hepatic lymphoma: extremely rare
Hepatic leiomyosarcomas are rare primary malignant tumours derived from smooth muscle cells in the liver.
Hepatic leiomyosarcoma is rare 1. An equal sex distribution and a broad age range (5 months-66Y) has been reported. Some have suggested an associated with AIDS 2.
Hepatic inflammatory pseudotumours (IPT) are rare benign hepatic lesions.
Most common in young adults with males affected more than females 7.
Aetiology is unknown 7.
Hepatic IPT is often seen as a well-circumscribed, encapsulated inflammator...
Hepatic haemosiderosis refers to the deposition of haemosiderin in the liver.
Hepatic iron overload can be in the form of 7:
In the absence of genetic haemochromatosis and syste...
Hepatic haemangiomas, also known as hepatic venous malformations, are benign non-neoplastic hypervascular liver lesions. They are frequently diagnosed as an incidental finding on imaging, and most patients are asymptomatic. From a radiologic perspective, it is important to differentiate haemangi...
Haemorrhagic pancreatitis is a possible uncommon complication that can occur with pancreatitis and is characterised by bleeding within or around the pancreas. It is usually considered a late sequela of acute pancreatitis.
Haemorrhage can occur in patients with severe necrotising panc...
Pseudocirrhosis is a term used to recapitulate imaging findings of cirrhosis, but occurring in the setting of hepatic metastases. It is most commonly reported following chemotherapeutic treatment of breast cancer metastases, although has also been reported prior to treatment, and with other mali...
Splenomegaly is a term which refers to enlargement of the spleen. The normal adult splenic length upper limit is usually around 12-15 cm. Also one should know how to calculate splenic index, volume and mass by CT and MR techniques. Massive splenomegaly is a term used when the spleen weighs >1000...