Articles
Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.
631 results found
Article
Caroli syndrome
Caroli disease and Caroli syndrome are congenital disorders comprising of multifocal cystic dilatation of segmental intrahepatic bile ducts. Caroli disease is limited to the dilatation of larger intrahepatic bile ducts, whereas Caroli syndrome describes the combination of small bile ducts dilata...
Article
Caudate–right lobe ratio
Caudate-right lobe ratio (C/RL) is used in the assessment of livers, usually in the setting of cirrhosis, in which there is atrophy of the right lobe with hypertrophy of the caudate lobe.
Method for measuring
image: axial slice immediately below the bifurcation of the main portal vein
line 1...
Article
Cavernous transformation of the portal vein
Cavernous transformation of the portal vein (CTPV) is a sequela of portal vein thrombosis and is the replacement of the normal single channel portal vein with numerous tortuous venous channels.
For a discussion of demographics and presentation, please refer to the article on portal vein thrombo...
Article
CEA
Serum CEA (carcinoembryonic antigen) is a cell-adhesive glycoprotein that was discovered in colorectal cancer in 1965, and is hence one of the oldest and most used tumor markers. Its name derives from its normal expression in fetoembryonic liver, gut and pancreas tissue.
Normal range of CEA is ...
Article
Ceftriaxone-associated gallbladder pseudolithiasis
Ceftriaxone-associated gallbladder pseudolithiasis is a not uncommon complication of this common antibiotic, where a ceftriaxone-calcium precipitate forms gallbladder sludge. It appears more common in pediatric patients.
Epidemiology
In one series, 25% of pediatric patients developed gallbladd...
Article
Chain of lakes sign
The chain of lakes sign is a radiological finding describing the appearance of the pancreatic ducts in cases of chronic pancreatitis. Due to repeated inflammation, fibrosis occurs and results in damage and atrophy of the pancreatic tissue as well as dilatation and beading of the main pancreatic ...
Article
Champagne sign (gallbladder)
The champagne sign (also known as the effervescent gallbladder sign) is a pathognomonic sonographic sign of gas in the gallbladder.
The sign refers to multiple small echogenic foci which are seen to migrate from a dependent to non-dependent position within the gallbladder as the patient changes...
Article
Charcot triad
Charcot triad is the finding of pyrexia, right upper quadrant pain and jaundice, and is a traditional clinical sign of acute cholangitis.
A meta-analysis of 4288 patients in 16 studies found that the sensitivity of Charcot triad for acute cholangitis was poor (36.3%) with a much better specific...
Article
Chemotherapy induced cholangitis
Chemotherapy induced cholangitis is caused when intra-arterial chemotherapy is introduced to treat liver metastases. This causes strictures of the common hepatic duct and main ducts, but spares distal and proximal (i.e. common bile duct and intrahepatic ducts).
Radiographic features
similar t...
Article
Child-Pugh score
The Child-Pugh score is a scoring system to measure the severity of chronic liver disease inclusive of cirrhosis. The intention is to provide a system with which clinicians can objectively communicate about liver function.
The score is composed from several categories:
total bilirubin, μmol/L ...
Article
Cholangiocarcinoma
Cholangiocarcinomas (bile duct cancers) are malignant epithelial tumors arising from the biliary tree, excluding the gallbladder or ampulla of Vater. Cholangiocarcinoma is the second most common primary hepatobiliary malignancy after hepatocellular carcinoma (HCC). They tend to have a poor progn...
Article
Cholangiocarcinoma (staging)
Cholangiocarcinoma staging is most commonly classified using the TNM staging systems of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC), which starting January 1, 2018 is according to its 8th edition. There are separate systems depending on whether the...
Article
Cholangiohepatoma
Cholangiohepatoma, also referred to as mixed hepatocellular cholangiocarcinoma (HCC-CC), refers to synchronous cholangiocarcinoma and hepatocellular carcinoma (HCC) in the same tumor. It is a rare and aggressive primary hepatic tumor combination. The origin of cholangiohepatoma is closely linked...
Article
Cholangitis
Cholangitis is a relatively broad descriptive term referring to inflammation of the bile ducts.
It has many forms and can arise from a number of situations:
primary sclerosing cholangitis
chemotherapy induced cholangitis
eosinophilic cholangitis 5
infective cholangitis
EBV cholangitis
ac...
Article
Cholecystectomy
Cholecystectomies are one of the most common surgical procedures performed. Evidence of a cholecystectomy is often seen on imaging procedures with surgical clips in the gallbladder fossa and radiologists should be aware of possible complications.
Indications
cholelithiasis
cholecystitis
gal...
Article
Cholecystitis
Cholecystitis refers to any form of inflammation involving the gallbladder and has many forms including:
acute cholecystitis
acute acalculous cholecystitis
acute calculous cholecystitis
chronic cholecystitis
emphysematous cholecystitis
suppurative cholecystitis
xanthogranulomatous cholecy...
Article
Choledochal cyst
Choledochal cysts represent congenital cystic dilatations of the biliary tree. Diagnosis relies on the exclusion of other conditions (e.g. tumor, gallstone, inflammation) as a cause of biliary duct dilatation.
Epidemiology
Choledochal cysts are rare, with an incidence of 1:100,000-150,000. Alt...
Article
Choledochocele
Choledochoceles refer to a specific type of choledochal cyst (type III under the Todani classification system). In this type, there is dilatation of the intramural portion of the distal common bile duct within the duodenal wall. Its precise etiology is not clear 3. Patients are usually adolescen...
Article
Choledocholithiasis
Choledocholithiasis denotes the presence of gallstones within the bile ducts (including the common hepatic duct/common bile duct).
Epidemiology
Choledocholithiasis is relatively common, seen in 6-12% of patients who undergo cholecystectomy 2.
Clinical presentation
Stones within the bile duct...
Article
Cholescintigraphy
Cholescintigraphy is the use of radiotracers to assess the anatomy and function of the biliary system (and the liver indirectly). Currently, this is most commonly performed with Tc-99m-IDA analogs, and "h"epatic "IDA" imaging gave rise to the more common term "HIDA scan."
After intravenous inje...
Article
Chronic cholecystitis
Chronic cholecystitis refers to prolonged inflammatory condition that affects the gallbladder. It is almost always seen in the setting of cholelithiasis (95%), caused by intermittent obstruction of the cystic duct or infundibulum or dysmotility.
Clinical presentation
Patients may have a histor...
Article
Chronic pancreatitis
Chronic pancreatitis represents the end result of a continuous, prolonged, inflammatory, and fibrosing process that affects the pancreas. This results in irreversible morphologic changes and permanent endocrine and exocrine pancreatic dysfunction.
Epidemiology
The most common cause of chronic ...
Article
Ciliated hepatic foregut cyst
Ciliated hepatic foregut cysts are a very rare type of hepatic cyst, with non-specific radiological features. They are usually benign, but rare cases of malignant degeneration (to squamous cell carcinoma) have also been reported.
Epidemiology
They are more often seen in adults, although a few...
Article
Cirrhosis
Cirrhosis (rare plural: cirrhoses) is the common endpoint of a wide variety of chronic liver disease processes which cause hepatocellular necrosis. Cirrhosis can be diagnosed with ultrasound, CT, and MRI, and these imaging modalities can also be used to evaluate for possible complications of cir...
Article
Cirrhosis (CNS manifestations)
There are several central nervous system complications that can arise in the setting of cirrhosis, which can be classified as those which are general (essentially hepatic encephalopathy) and those that are specific to the cause of cirrhosis.
General manifestations
The major manifestation is he...
Article
Cirrhosis (musculoskeletal manifestations)
There are several musculoskeletal complications that can arise in the setting of cirrhosis 1:
stigmata of portal hypertension, mainly abdominal wall varices
hemorrhagic complications due to coagulopathy:
spontaneous rectus hematoma
postparacentesis abdominal wall bleeding
infective complica...
Article
Cirrhosis (pulmonary manifestations)
There are several pulmonary complications that can arise in the setting of cirrhosis:
hepatopulmonary syndrome (HPS): considered the commonest
portopulmonary hypertension (POPH)
hepatic hydrothorax (HH)
intrathoracic portosystemic collateral vessel formation
The development of portal hypert...
Article
Clonorchiasis
Clonorchiasis is a trematodiasis caused by chronic infestation by Clonorchis sinensis and can lead to recurrent pyogenic cholangitis, biliary strictures and cholangiocarcinoma.
Epidemiology
Infection with Clonorchis sinensis occurs in endemic areas, mainly east China. Over 85 million people a...
Article
Cluster sign
The cluster sign is a finding on MRI and CT that is associated with pyogenic hepatic abscesses and can help differentiate pyogenic abscesses from other types of liver lesions.
Radiographic features
The cluster sign is best seen on MRI T2-weighted and postcontrast T1-weighted sequences. Small n...
Article
Coarsened hepatic echotexture
Coarsened hepatic echotexture is a sonographic descriptor used when the uniform smooth hepatic echotexture of the liver is lost. This can occur due to a number of reasons which include:
conditions that cause hepatic fibrosis 1
cirrhosis
hemochromatosis
various types of hepatitis 3
particula...
Article
Celiac artery
The celiac artery, also known as the celiac axis or celiac trunk, is a major visceral artery in the abdominal cavity supplying the foregut. It arises from the abdominal aorta and commonly gives rise to three branches: left gastric artery, splenic artery, and common hepatic artery.
Gross anatom...
Article
Celiacomesenteric trunk
The celiacomesenteric trunk (CMT) represents an uncommon vascular anatomical variant where both the celiac trunk and the superior mesenteric artery have a common origin from the abdominal aorta as a single trunk. Its frequency has been reported to occur in about 1.5% of the population 1,2.
Four...
Article
Common bile duct
The common bile duct (CBD), which is sometimes simply known as the bile duct, is formed by the union of the cystic duct and common hepatic duct (CHD).
Terminology
On ultrasound imaging, it is not always possible to confidently see where the cystic duct enters the common hepatic duct to form t...
Article
Common hepatic artery
The common hepatic artery (CHA) is one of the 3 branches of the celiac artery.
Gross anatomy
Origin
The common hepatic artery is normally a terminal branch of the celiac artery, the largest branch coursing to the right.
Course
It passes anterior to the pancreas, and then inferiorly to the r...
Article
Common variable immunodeficiency (hepatic manifestations)
Hepatic manifestations of common variable immunodeficiency are not uncommon and can be primarily related to nodular regenerative hyperplasia.
For a general discussion of the underlying condition, please refer to the article on common variable immunodeficiency (CVID).
Epidemiology
General liv...
Article
Compression-type hepatic pseudolesions
Compression-type hepatic pseudolesions occur typically when an extrinsic structure, during the patient's deep inspiration breath-hold at the time of CT acquisition, causes transient focal compression of a subcapsular region of the liver and subsequent decreased portal perfusion and minimal chang...
Article
Confluent hepatic fibrosis
Confluent hepatic fibrosis is a possible result of chronic injury to the liver, most commonly from cirrhosis or hepatic vascular injury.
Radiographic features
Confluent hepatic fibrosis is a cause of wedge-shaped or concave-marginated abnormalities in the cirrhotic liver: it occurs more freque...
Article
Congestive hepatopathy
Congestive hepatopathy includes a spectrum of hepatic derangements that can occur in the setting of right-sided heart failure (and its underlying causes). If there is subsequent hepatic fibrosis the term cardiac cirrhosis may be used. The condition can rarely occur as a result of non-cardiac cau...
Article
Contrast-enhanced ultrasound
Contrast-enhanced ultrasound (CEUS) involves the administration of intravenous contrast agents consisting of microbubbles/nanobubbles of gas.
Ultrasound contrast agents
First generation
First-generation ultrasound contrast agents contained microbubbles of air that were dissolved in blood when...
Article
Copper
Copper (chemical symbol Cu) is one of the trace elements. It has an important biological role as a redox agent and as a cofactor in cuproproteins, facilitating many vital metabolic reactions.
Chemistry
Basic chemistry
Copper is a transition metal with the atomic number 29 and an atomic weight...
Article
Copper toxicity
Copper toxicity, also known as copper poisoning or copperiedus, is the pathological result of excess elemental copper in the body. It may be acute, resulting in acute copper toxicosis, or a more chronic form, typified by Wilson disease.
Clinical presentation
Acute copper toxicosis
Acute toxi...
Article
Cottage loaf sign (liver)
The cottage loaf sign occurs as a result of a right-sided diaphragmatic rupture with partial herniation of the liver through the diaphragmatic defect. The herniated component is separated by a waist at the diaphragm from the larger intra-abdominal component. This shape is reminiscent of a cottag...
Article
Couinaud classification of hepatic segments
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...
Article
Couinaud classification of hepatic segments (mnemonic)
Pauli et al published a "handy" way to remember the Couinaud classification of hepatic segments 1.
Make a fist with your right hand. The fingers should be wrapped around the flexed thumb and the fist should face you. The segments are represented by the following:
segment 1: (caudate): the thum...
Article
Courvoisier sign (hepatobiliary)
Courvoisier sign or Courvoisier-Terrier sign states that in a patient with painless jaundice and an enlarged gallbladder (or right upper quadrant mass), the cause is unlikely to be gallstones and therefore presumes the cause to be an obstructing pancreatic or biliary neoplasm until proven otherw...
Article
CT cholangiography
CT cholangiography is a technique of imaging the biliary tree with the usage of hepatobiliary excreted contrast. It is useful in delineating biliary anatomy, identifying a bile leak or looking for retained gallstones within the biliary system.
Indications
Second-line test (after ultrasound) wh...
Article
CT liver volumetry in living donor liver transplantation (approach)
CT liver volumetry in living donor liver transplantation is essential imaging studies in preoperative assessment.
Liver volumetry is performed for the donor liver to calculate the graft volume and remnant liver volume. Preoperative measurement of liver volume is important to avoid graft mismatc...
Article
CT liver volumetry (liver transplantation protocol)
CT liver volumetry is an essential imaging study in preoperative assessment for living donor liver transplantation.
NB: This article is intended to outline some general principles of protocol design. The specifics will vary depending on CT hardware and software, radiologists' and referrers' pre...
Article
CT polytrauma (technique)
CT polytrauma/multitrauma, also called trauma CT, whole body CT (WBCT) or panscan, is an increasingly used investigation in patients with multiple injuries sustained after significant trauma.
Clinical assessment and mechanism of injury may underestimate injury severity by 30% 8. There is some e...
Article
CT severity index in acute pancreatitis
The CT severity index (CTSI) is based on findings from an enhanced CT scan to assess the severity of acute pancreatitis. The severity of acute pancreatitis CT findings has been found to correlate well with clinical indices of severity.
The CT severity index sums two scores:
Balthazar score: g...
Article
Cyst
A cyst is an abnormal fluid-filled structure which is lined by epithelium; with one exception: lung cysts may contain gas or fluid. By contradistinction, a pseudocyst lacks an epithelial lining and instead has a vascular and fibrotic capsule.
Cysts are extremely common and found in most organs....
Article
Cystic artery
The cystic artery is the main artery supplying the gallbladder. It most commonly arises from the right hepatic artery within Calot triangle 1.
Gross anatomy
The cystic artery typically passes posterior to the cystic duct to reach the neck of the gallbladder. At this point, it gives off two-to-...
Article
Cystic fibrosis
Cystic fibrosis (CF), also called mucoviscidosis, is an autosomal recessive genetic disease that affects the exocrine function of the lungs, liver, pancreas, small bowel, sweat glands, and the male genital system 11. resulting in progressive disability and multisystem failure. This article is a ...
Article
Cystic hepatic metastases
Cystic hepatic metastases are included in the differential for new cystic liver lesions. The internal cystic component may represent necrosis as the tumor outgrows its hepatic blood supply, or it may represent a mucinous component, similar to the primary tumor.
The liver and lungs are the most ...
Article
Cystic lesions of the liver (differential)
Cystic lesions of the liver carry a broad differential diagnosis:
simple cysts
simple hepatic cyst
biliary hamartoma
Caroli disease
adult polycystic liver disease
ciliated hepatic foregut duplication cyst 6
infectious: inflammatory conditions
hepatic abscess
pyogenic hepatic abscess
am...
Article
Cystic lesions of the pancreas (differential)
The differential for cystic lesions of the pancreas includes:
unilocular
pancreatic pseudocyst
intraductal papillary mucinous neoplasm (IPMN)
serous cystadenoma uncommonly uni/macrolocular
simple pancreatic cyst
pancreatic cysts occur in association with
von Hippel Lindau syndrome
autos...
Article
Cystic lymph node of Lund
The cystic lymph node of Lund (also known as the Calot or Mascagni node) is the sentinel node for the gallbladder, and one of the structures in Calot triangle. It lies in close proximity to the cystic artery and is one of the structures removed during cholecystectomy.
History and etymology
The...
Article
Denver shunt
A Denver shunt, or peritoneovenous shunt, is a device used to shunt ascites to the superior vena cava in patients with refractory ascites.
The proximal end is located in the peritoneal cavity and the distal end in the superior vena cava, with a subcutaneous course in the anterior chest wall. It...
Article
Diabetes mellitus
Diabetes mellitus (DM) often referred to simply as diabetes, is a group of metabolic conditions characterized by hyperglycemia.
These conditions should not be confused with diabetes insipidus which is clinically distinct and not related to hyperglycemia.
Terminology
If a patient with diabete...
Article
Diabetic ketoacidosis
Diabetic ketoacidosis (DKA) is an acute, life-threatening complication that usually occurs in new-onset and established type 1 diabetic patients due to a state of severe insulin deficiency. This condition is characterized by hyperglycemia, ketoacidosis, and ketonuria.
Epidemiology
Diabetic ket...
Article
Diffuse gallbladder wall thickening (differential)
Diffuse thickening of the gallbladder wall can occur in a number of situations:
cholecystitis
acute cholecystitis
chronic cholecystitis
gallbladder empyema 7
xanthogranulomatous cholecystitis 11
acalculous cholecystitis11
postprandial physiological state (pseudothickening)
gallbladder o...
Article
Diffuse hepatic steatosis
Diffuse hepatic steatosis, also known as fatty liver, is a common imaging finding and can lead to difficulties assessing the liver appearances, especially when associated with focal fatty sparing.
Terminology
The term 'fatty infiltration of the liver' is often erroneously used to describe live...
Article
Diffuse hepatic steatosis (grading)
Grading of diffuse hepatic steatosis on ultrasound has been used to communicate to the clinician about the extent of fatty changes in the liver.
Grading
grade I: diffusely increased hepatic echogenicity but periportal and diaphragmatic echogenicity is still appreciable
grade II: diffusely in...
Article
Distal cholangiocarcinoma (staging)
Distal cholangiocarcinoma staging is defined according to the TNM staging classification of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC). As of 2018, the staging criteria are in their 8th edition and reflected below 1. These criteria apply to cancer...
Article
Dorsal pancreatic artery
The dorsal pancreatic artery is a branch of the splenic artery that supplies the pancreas. It arises from the proximal splenic artery and descends a short distance to run along the posterior margin of the pancreas where it divides in to left and right branches.
the right branches pass either an...
Article
Double barrel sign (disambiguation)
Double barrel sign is an imaging appearance of two lumens adjacent to each other.
It can be seen in:
dilated bile duct adjacent to portal vein
double barrel aorta: aortic dissection
double barrel esophagus: esophageal dissection
Article
Double duct sign
The double duct sign refers to the presence of simultaneous dilatation of the common bile and pancreatic ducts. Being an anatomical sign it can be seen on all modalities that can visualize the region, including: MRI, CT, ultrasound and endoscopic retrograde cholangiopancreatography (ERCP).
The...
Article
Double target sign (hepatic abscess)
The double target sign is a characteristic imaging feature of liver abscess on contrast-enhanced CT scans, in which a central, fluid-filled low attenuation lesion is surrounded by a high attenuation inner rim and a low attenuation outer ring 1,2.
The inner ring (abscess membrane) demonstrates e...
Article
Duct penetrating sign (pancreas)
Duct penetrating sign is a radiographic sign that can be useful in differentiating between focal pancreatitis (inflammatory pancreatic mass) from pancreatic carcinoma.
A positive sign is when a mass is penetrated by an unobstructed pancreatic duct; this makes focal pancreatitis the most likely ...
Article
Dysplastic liver nodules
Dysplastic liver nodules are focal nodular regions (≥1 mm) without definite evidence of malignancy.
Epidemiology
They have been found in cirrhotic patients with a prevalence of 14% (size >1.0 cm) to 37% (size >0.5 cm) 2.
Associations
cirrhosis
Pathology
Dysplasia indicates:
nuclear atypia...
Article
EBV associated smooth muscle tumor
Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) are rare and encountered in immunocompromised individuals.
Epidemiology
These tumors are generally exceedingly rare, and only seen with any frequency in the setting of immunosuppression, particularly in HIV/AIDS patients, but also po...
Article
Ectopic intracaval liver
Ectopic intracaval liver is a very rare congenital abnormality of the liver in which a part of the liver, not contiguous with the liver proper, lies within the inferior vena cava (IVC).
Ectopic hepatic lobes elsewhere have been described rarely as congenital abnormalities, but a location withi...
Article
Ectopic pancreatic tissue
Ectopic pancreatic tissue, also known as heterotopic pancreatic tissue, refers to the presence of pancreatic tissue in the submucosal, muscularis or subserosal layers of the luminal gastrointestinal tract outside the normal confines of the pancreas and lacking any anatomic or vascular connection...
Article
Emphysema (disambiguation)
Emphysema refers to any disease process involving an abnormal accumulation of air/gas in the tissues. When used alone, it is usually taken to mean the lung disease, pulmonary emphysema, which forms part of the spectrum of chronic obstructive pulmonary disease (COPD).
gastric emphysema: include...
Article
Emphysematous cholecystitis
Emphysematous cholecystitis is a rare form of acute cholecystitis where gallbladder wall necrosis causes gas formation in the lumen or wall. It is a surgical emergency, due to the high mortality from gallbladder gangrene and perforation.
Epidemiology
Men are affected twice as commonly as women...
Article
Emphysematous hepatitis
Emphysematous hepatitis is a very rare condition characterized by a gas-forming infection of the liver, which in all reported cases has been rapidly fatal. Diabetes mellitus commonly coexists.
Epidemiology
Emphysematous hepatitis is extremely rare, with less than 10 reported cases in the lite...
Article
Endocrine tumors of the pancreas
Endocrine tumors of the pancreas, also known as pancreatic neuroendocrine tumors (pNET), arise from the pancreatic islet cells and include some distinct tumors that match the cell type of origin.
Terminology
Pancreatic endocrine tumors have commonly been referred to as "islet cell tumors", re...
Article
Endoscopic retrograde cholangiopancreatography
Endoscopic retrograde cholangiopancreatography (ERCP) is a diagnostic and interventional procedure technique using both endoscopy and fluoroscopy for examination and intervention of the biliary tree and pancreatic ducts. It is typically performed by doctors with endoscopic qualifications (e.g. g...
Article
Epidermoid cyst
Epidermoid cysts are nonneoplastic inclusion cysts derived from ectoderm that are lined solely by squamous epithelium. These are discussed separately by anatomic location:
epidermal inclusion cyst
intracranial epidermoid cyst
splenic epidermoid cyst
spinal epidermoid cyst
testicular epiderm...
Article
EUS-guided biliary drainage
Endoscopic ultrasound (EUS)-guided biliary drainage is an alternative to conventional transpapillary and percutaneous biliary drainage in where an extra-anatomic route is created between the biliary tree and the gastrointestinal tract.
Indications
failed endoscopic transpapillary biliary drai...
Article
Exclamation mark sign (limy bile)
The exclamation mark sign is a pathognomonic imaging sign of the rare diagnosis of limy bile on plain abdominal radiography. It occurs when there is both limy bile and a gallstone in the common bile duct. The linear vertical radiopaque bile forms the line of the exclamation mark (i.e. !), whilst...
Article
Exophytic hepatic mass
Exophytic hepatic mass or tumor is a lesion which predominantly lies outside the margins of liver but originates from within the liver.
Pathology
Causes include 1:
benign
hepatic hemangioma
hepatic adenoma
hepatic cyst
hepatic angiomyolipoma
focal nodular hyperplasia
malignant
hepati...
Article
Extrahepatic portal vein obstruction
Extrahepatic portal vein obstruction is the most common cause of non-cirrhotic portal hypertension in children and young adults in developing countries. It may or may not extend into the intrahepatic portal vein.
Clinical presentation
It usually occurs in children and young adults, presenting ...
Article
Extramedullary hematopoiesis
Extramedullary hematopoiesis is a response to the failure of erythropoiesis in the bone marrow.
This article aims to a general approach on the condition, for a dedicated discussion for a particularly involved organ, please refer to the specific articles on:
extramedullary hematopoiesis in the...
Article
Extrapulmonary tuberculosis
Extrapulmonary tuberculosis (TB) refers to the hematogenous spread of Mycobacterium tuberculosis.
Pathology
Extrapulmonary tuberculosis 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 ...
Article
Falciform artery
The falciform artery, also known as the hepatic falciform artery (FHA) is an uncommon vascular anatomic variant that most commonly arises as the terminal branch of the middle hepatic artery which courses anteriorly through the falciform ligament into and supplying the supraumbilical anterior abd...
Article
Falciform ligament
The falciform ligament is a broad and thin peritoneal ligament. It is sickle-shaped and a remnant of the ventral mesentery of the fetus.
It is situated in an anteroposterior plane but lies obliquely so that one surface faces forward and is in contact with the peritoneum behind the right rectus ...
Article
Familial atypical multiple mole melanoma syndrome
Familial atypical multiple mole melanoma (FAMMM) syndrome is an autosomal dominant genodermatosis characterized by multiple melanocytic nevi (often more than 50) and a family history of melanoma.
Pathology
Genetics
It is associated with mutations in the CDKN2A gene and shows reduced penetranc...
Article
Fat containing liver lesions
Fat containing liver lesions represent a variety of benign and malignant liver lesions may contain macroscopic and/or intracytoplasmic fat in sufficient quantities enabling characterization on imaging studies. Most fat-containing liver lesions (80%) in patients with cirrhosis are malignant, most...
Article
Fetal hepatomegaly
Fetal hepatomegaly (or more simply an enlarged fetal liver) can occur in number of situations. It can occur with or without fetal splenomegaly.
Pathology
Etiology
in utero infections: the commonest cause
fetal cytomegalovirus infection (CMV) 3
fetal parvovirus B19 infection
in utero syph...
Article
Fetal intrahepatic calcification
Fetal intrahepatic calcification can be a relatively common finding. Calcifications in the liver can be single or multiple and in most cases in which isolated hepatic calcific deposits are detected, there is usually no underlying abnormality.
The presence of isolated intrahepatic calcification ...
Article
Fibrolamellar hepatocellular carcinoma
Fibrolamellar hepatocellular carcinoma is a distinct histological variant of hepatocellular carcinoma characterized on microscopy by laminated fibrous layers between the tumor cells. It is important as it has different demographics and risk factors compared to 'standard' hepatocellular carcinoma...
Article
Fibropolycystic liver disease
Fibropolycystic liver disease is a collective term for a group of congenital liver and biliary abnormalities resulting from abnormal development of the ductal plates. Disease in this group include:
congenital hepatic fibrosis
biliary hamartomas
autosomal dominant polycystic disease
Caroli d...