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.

458 results found
Article

Pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma makes up the vast majority (~90%) of all pancreatic neoplasms and remains a disease with a very poor prognosis and high morbidity. On imaging, it usually presents as a hypodense mass on CT that is poorly marginated, which may encase vessels and the common biliar...
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Atoll sign (liver MRI)

The atoll sign in hepatic imaging has been described when a liver lesion shows a peripheral rim of high T2 signal intensity with the centre of the lesion appearing isointense to the background of non-cirrhotic liver on T2WI mimicking an atoll. It is considered a characteristic sign of an inflamm...
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Hepatolithiasis

Hepatolithiasis is the presence of bile duct stones within the intrahepatic bile ducts, specifically before the confluence of the right and left hepatic ducts.  Epidemiology Hepatolithiasis is common Asia and the Pacific, with a prevalence of ~40%. It is rare in the West with a prevalence of ~...
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Low phospholipid-associated cholelithiasis syndrome

Low phospholipid-associated cholelithiasis (LPAC) syndrome is one of the syndromes associated with ABCB4/MDR3 mutation. Characteristics of this syndrome include 1,2: intrahepatic microlithiasis/sludge symptomatic cholesterol stones with early onset (<40 years) recurrent symptoms post cholecys...
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Hepatic capsular retraction (mnemonic)

The following mnemonics can be used as reminders of the causes of hepatic capsular retraction: CT CHIEF FILTH E Mnemonics CT CHIEF C: cholangiocarcinoma (intrahepatic) T: treated hepatic metastasis or hepatocellular carcinoma C: cirrhosis with confluent hepatic fibrosis H: haemangioma (e...
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Lemmel syndrome

Lemmel syndrome is defined as an obstructive jaundice caused by a periampullary duodenal diverticulum (of the second part of the duodenum) compressing the intrapancreatic part of the common bile duct with resultant upstream dilatation of the extra- and intrahepatic bile ducts. Clinical presenta...
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Periampullary diverticulum

A periampullary diverticulum is a location-specific type of duodenal diverticulum.  Epidemiology The incidence is reported to increase with age with reported rates as high as 27%. Pathology It is located close to the region of the duodenum often involving the D2 segment.  Associations can ...
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Acute peripancreatic fluid collection

Acute peripancreatic fluid collections (APFC) are an early complication of acute pancreatitis that usually develop in the first four weeks. After four weeks, the term pseudocysts is used. The absence of necrosis differentiates APFCs from acute necrotic collections (ANC), that is, APFCs occur in ...
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Pancreatic atrophy

Pancreatic atrophy is non-specific and is common in elderly patients, although in younger patients it can be a hallmark of pathology. Most commonly it is associated with aging, obesity and end-stage chronic pancreatitis.  It occurs principally with fatty replacement of the pancreas (pancreatic ...
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Abscess

Abscesses are focal confined collections of suppurative inflammatory material and can be thought of as having three components 1: a central core consisting of necrotic inflammatory cells and local tissue peripheral halo of viable neutrophils surrounded by a 'capsule' with dilated blood vessel...
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Portal venous gas

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...
Article

Intrabiliary rupture of hepatic hydatid cyst

Intrabiliary rupture of hepatic hydatid cyst is a common complication associated with hepatic hydatid cysts. It is important to appreciate the direct and indirect signs of this condition. Radiographic features The radiological features of intrabiliary rupture of a hepatic hydatid cyst can be c...
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Liver

The liver is the largest abdominal organ that plays a major role in metabolism and has a number of functions, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification. It is one of very few organs that has the ability to regen...
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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...
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Focal nodular hyperplasia

Focal nodular hyperplasia (FNH) is a regenerative mass lesion of the liver and the second most common benign liver lesion (most common is cavernous haemangioma). Many FNHs have characteristic radiographic features in multimodality imaging, but some lesions may be atypical in appearance. FNHs are...
Article

Posterior right subhepatic space

The posterior right subhepatic space (also known as the hepatorenal fossa or Morison's pouch) separates the liver from the right kidney. It is a potential space that is not filled with any fluid in normal conditions. Gross anatomy Posterior right subhepatic space is a subcompartment of the sup...
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Ascites

Ascites is defined as an abnormal amount of intraperitoneal fluid. Clinical presentation Patients with a large volume of ascites can present with abdominal distension (which may be painful), nausea, vomiting, dyspnoea and peripheral oedema 7, 9. Pathology Ascitic fluid is traditionally chara...
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Target sign (tuberculosis)

The target sign of tuberculosis refers to the bull's-eye appearance of some parenchymal tuberculomas involving the brain (see: CNS tuberculosis) and solid abdominal organs (see: hepatic and splenic tuberculosis) on cross-sectional imaging.  Radiographic features Ultrasound hypoechoic nodules ...
Article

Coeliac artery

Coeliac artery (also known as the coeliac axis or trunk) is a major visceral artery in the abdominal cavity.  Gross anatomy Origin Arises anteriorly from abdominal aorta at the T12 level, behind the median arcuate ligament, just as the aorta enters the abdomen.  Course It is typically a sho...
Article

Splenic infarction

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.   Epidemiology Splenic infarcts can occur due to a number processes, involving either arterial supply, the spleen itself and the ...
Article

CA-125

Serum CA-125 is well recognised as an ovarian cancer-associated marker and is an antigen determinant on a high-molecular-weight glycoprotein. The normal range of CA-125 is 0-35 U/mL. Serum CA-125 levels can also be used to monitor the response to treatment as well as a prognostic indicator sinc...
Article

Wirsungocele

Wirsungocele refers to a cystic dilatation of the pancreatic duct of Wirsung, which is the portion of ventral duct between the dorsal-ventral junction and major duodenal papilla. It is believed to be analogous to choledochocele and santorinicele. Clinical presentation It may be an incidental f...
Article

Aneurysms of the portal venous system

Aneurysms of the portal vein are extremely rare and represent only 3% of all aneurysms of the venous system 1. Clinical presentation Most patients are asymptomatic but may present with nonspecific abdominal pain as a major symptom 2-4. Pathology Both congenital and acquired causes have been ...
Article

Hepatic infarction

Hepartic infarction is an extremely rare situation because of the liver's dual blood supply by the hepatic artery and portal vein. Hepatic infarction can occur when there is both hepatic arterial and portal vein flow compromise but most cases are due to acute portal venous flow compromise 11. E...
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Pneumobilia vs portal venous gas (mnemonic)

Pneumobilia and portal venous gas are two causes of an intrahepatic branching gas pattern. The two have different causes and implications and need to be distinguished on imaging. Mnemonic A simple mnemonic for remembering the difference in appearance is: portal venous gas: peripheral common ...
Article

TIPS evaluation

TIPS evaluation is useful to ensure that the shunt is working properly and that no stenosis has occurred within the stent. Ultrasound is often used as a first-line modality. Radiographic features Ultrasound The normal TIPS should show colour Doppler flow throughout its length. The in-stent ve...
Article

Inflammatory hepatic adenoma

Inflammatory hepatic adenomas are a genetic and pathological subtype of hepatic adenoma. Their appearance and prognosis is different than other subtypes and has highest incidence of haemorrhage amongst hepatic adenoma subtypes. Epidemiology Most common subtype of hepatic adenoma (40-50%). Occu...
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Periportal halo

Periportal halo or periportal collar sign is a zone of low attenuation seen around the portal veins on contrast-enhanced CT or hypoechogenicity on liver US. Periportal halos may occur around the central portal veins or their peripheral branches and occurs on both sides of the portal triads. Pat...
Article

Gallstones

Gallstones, also called cholelithiasis, are concretions that occur anywhere within the biliary system, most commonly within the gallbladder.  Terminology Gallstones (cholelithiasis) describes stone formation at any point along the biliary tree. Specific names can be given to gallstones dependi...
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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 p...
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Right posterior hepatic notch sign

The right posterior hepatic notch sign is a sharp indentation of the normally smooth posterior right hepatic lobe margin. It is associated with cirrhosis, although the mechanism is not entirely clear. It has been suggested that this may be an indication of relative caudate lobe hypertrophy and d...
Article

Splenomegaly

Splenomegaly is a term which refers to enlargement of the spleen. The normal adult splenic length upper limit is usually around 12-15 cm. Pathology The causes of splenomegaly are protean, and can be thought of under a number of headings: haematological disease haemodynamic infectious stora...
Article

Haemochromatosis

Haemochromatosis is an iron overload disorder characterised by a progressive increase in total body iron stores and deposition of iron in some non-reticuloendothelial system (RES) body organs which results in some instances in organ dysfunction. This article focus on the general principles of h...
Article

Hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver. It is strongly associated with cirrhosis, from both alcohol and viral etiologies. HCC constitutes approximately 5% of all cancers partly due to the high endemic rates of hepatitis B infection 1. Epidemiology HCC...
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Splenorenal shunt

A splenorenal shunt refers to an abnormal collateral portosystemic communication between the splenic vein and the left renal vein. It is one of the features of portal hypertension. See also portosystemic shunts
Article

Medical devices in the abdomen and pelvis

Medical devices in the abdomen and pelvis are important to be recognised, just like medical devices of the chest. Often we ignore these devices, considering them to be incidental and non-pathological, however it is essential to be aware of potential complications. Gastrointestinal tubes stomac...
Article

Increased splenic density

Increased splenic density can be due to a number of processes. The density may be due to calcification (most common) or other compounds (iron, Thorotrast), and can be seen (often incidentally) on abdominal radiographs and CT. On CT the usual splenic attenuation is 35-55 HU or ~10 HU 6 lower than...
Article

Portal vein

The portal vein (PV) (sometimes referred to as the main or hepatic portal vein) is the main vessel in the portal venous system and drains blood from the gastrointestinal tract and spleen to the liver. Gross anatomy The portal vein, usually measures approximately 8 cm in length in adults. It or...
Article

Gallbladder volvulus

Gallbladder volvulus is a relatively rare condition in which there is a rotation of the gallbladder around the axis of the cystic duct and artery. Clinical presentation Symptoms are non-specific, however right upper quadrant pain and vomiting are similar to biliary colic. Laboratory evaluation...
Article

Gallbladder

The gallbladder is a pear-shaped musculomembranous sac, lodged in a fossa on the undersurface of the right lobe of the liver, and extending from near the right extremity of the porta hepatis to the anterior border of the liver.  Gross anatomy It typically measures from 7 to 10 cm in length and...
Article

5-F risk factors for cholelithiasis (mnemonic)

The 5-F rule refers to risk factors for the development of cholelithiasis in the event of upper abdominal pain: fair: more prevalent in the Caucasian population 1 fat: BMI >30 female fertile: one or more children forty: age ≥40 cholelithiasis can occur in young patients with a positive fam...
Article

Starry sky appearance on ultrasound

A "starry sky appearance" refers to a sonographic appearance of the liver parenchyma in which there are bright echogenic dots throughout a background of decreased liver parenchymal echogenicity. Although usually associated with acute hepatitis, this sign has been found to have poor sensitivity a...
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Mucocele

A mucocele simply refers to accumulation and expansion of a structure by mucus. It occurs in a variety of locations which are discussed separately: paranasal sinus mucocele oral cavity e.g. ranula, mucous retention cysts mucocele of the appendix 1 mucocele of the gallbladder mucocele of the...
Article

HELLP syndrome

HELLP syndrome is a pregnancy-related condition and is an abbreviation for: haemolysis elevated liver enzymes and  low platelets It is considered a severe and life threatening form of pre-eclampsia although it can occur without co-existing pre-eclampsia.  Epidemiology The estimated inciden...
Article

Paraduodenal pancreatitis

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. Terminology The following entities with which it shares clinicopathological features are unified by this term and should no ...
Article

Benign liver tumours (paediatric)

Paediatric benign liver tumours are a relatively rare, but important group of conditions. Importantly, the commonest cause of a benign liver tumour is specific to the paediatric population. The list in descending order of frequency is: infantile hepatic hemangioma (previously haemangioendotheli...
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Passive hepatic congestion

Passive hepatic congestion or congested liver in cardiac disease is the stasis of blood in the hepatic parenchyma, due to impaired hepatic venous drainage which leads to widening and splaying of the central hepatic veins and hepatomegaly.  Passive hepatic congestion is a well-studied result of ...
Article

Liver lesions (paediatric)

Paediatric liver lesions are a heterogeneous group that include infiltrative lesions and those that demonstrate mass effect. Moreover, they may be solitary or multiple, benign or malignant: benign liver tumours malignant liver tumours Epidemiology There are differing frequencies of both beni...
Article

Portal vein thrombosis

Portal vein thrombosis may be seen in a variety of clinical contexts, and when acute can be a life-threatening condition. It is a major cause of noncirrhotic presinusoidal portal hypertension. Portal vein thrombus may be either bland or malignant (i.e. tumour thrombus), and it is a critical find...
Article

Transient hepatic intensity difference

Transient hepatic intensity differences (THIDs) are a phenomenon observed on MRI imaging of the liver. They are considered a direct equivalent to transient hepatic attenuation differences (THADs) noted on CT. They may be focal or nonfocal. Pathology Focal lesions A focal THID lesion can arise...
Article

Transient hepatic attenuation differences

Transient hepatic attenuation differences (THAD) lesions refer to areas of parenchymal enhancement visible during the hepatic artery phase on helical CT. They are thought to be a physiological phenomenon caused by the dual hepatic blood supply. Occasionally they may be associated with hepatic tu...
Article

Splenic hydatid infection

Splenic hydatid infection is a rare form of Hydatid disease, and isolated splenic involvement is even less common. Epidemiology Splenic hydatid disease has been reported to constitute up to 4% of cases of abdominal hydatid disease 4. Pathology Splenic hydatid cysts are usually solitary. As t...
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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

Gallbladder carcinoma

Gallbladder carcinomas are usually asymptomatic until they reach an incurable stage. As such, early incidental detection is important, if the occasional patient is to be successfully treated. The majority (90%) are adenocarcinomas, and the remainder are squamous cell carcinomas.  Epidemiology ...
Article

Gallstone ileus

Gallstone ileus is an uncommon cause of a mechanical small bowel obstruction (SBO). 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.  Epidemiology ...
Article

Syphilis

Syphilis is the result of infection with the gram negative spirochete Treponema pallidum, subspecies pallidum. It results in a heterogeneous spectrum of disease with many systems that can potentially be involved, which are discussed separately.  Epidemiology Despite the discovery of penicillin...
Article

Anatomy curriculum

The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists. General anatomy Neuroanatomy Head and neck anatomy Thoracic anatomy Abdominal and pelvic anatomy Spinal anat...
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Cholangiohepatoma

Cholangiohepatoma refers to a synchronous cholangiocarcinoma and hepatocellular carcinoma. It is a rare and aggressive primary hepatic tumour. The origin of cholangiohepatoma is closely linked to the origin of cholangiocarcinoma rather than hepatocellular carcinoma (HCC). Epidemiology The inci...
Article

Percutaneous transhepatic cholangiography

Percutaneous transhepatic cholangiography (PTC) is a radiographic technique employed in visualisation of the biliary tree and can be used as the first step in a number of percutaneous biliary interventions (e.g. percutaneous transhepatic biliary stent placement) Indications Purely diagnostic p...
Article

Pneumobilia

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...
Article

Santorinicoele

A santorinicoele refers to a cystic dilatation of the end of the dorsal  pancreatic duct (duct of Santorini) 1,2 and is believed to be analogous to a dilatation of the most distal common bile duct, which is commonly known as a choledochocoele3.  It can occur in association with pancreas divisum...
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Pancreas divisum

Pancreas divisum represents a variation in pancreatic ductal anatomy that can be associated with abdominal pain and idiopathic pancreatitis. It is characterised, in the majority of cases, by the dorsal pancreatic duct (main pancreatic and Santorini ducts) directly entering the minor papilla with...
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Pancreatic trauma injury grading

A number of pancreatic injury grading systems have been proposed. Classifications American Association for the Surgery of Trauma (AAST) grade 1: haematoma with minor contusion/laceration but without duct injury grade 2: major contusion/laceration but without duct injury grade 3: distal lace...
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Benign tumours and tumour-like lesions of the gallbladder

The gallbladder and extrahepatic bile ducts play host to a surprisingly large number of benign tumours and tumour-like lesions which may be visible on imaging. In the gallbladder, most of them are detected incidentally, whereas in the bile ducts they are usually found in symptomatic patients (ob...
Article

Biliary tree anatomy

Various channels that collect bile from the hepatic parenchyma and transport it to the duodenum constitute the biliary tree. Gross anatomy 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...
Article

Hepatic metastases

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...
Article

Solid and hollow abdominal viscera

The solid abdominal viscera is a collective term for those internal organs of the upper abdomen that are primarily solid in nature, namely the liver, pancreas, spleen, adrenals, and kidneys. It is used in contradistinction to the hollow abdominal viscera, which includes, the stomach, small bowel...
Article

Imaging in liver transplantation

Imaging in liver transplantation is aimed to evaluate donor and recipient for successful transplantation and its outcome. Pre-transplant evaluation Donor volume of liver parenchymal disease (diffuse or focal) vascular anatomy arterial variations venous variations biliary anatomy Recipie...
Article

Giant hepatic venous malformation

Giant hepatic venous malformations (also known as giant hepatic haemangiomas) are relatively uncommon non-neoplastic vascular lesions of the liver, which can be strikingly large and mimic tumours.  Terminology It is important to note that according to newer nomenclature, these lesions are mere...
Article

Gallbladder empyema

Gallbladder empyema (suppurative cholecystitis1) is an uncommon complication of cholecystitis and refers to a situation where the gallbladder lumen is filled and distended by purulent material (pus). Epidemiology There is an increased incidence in those with diabetes 2 and/or advanced atherosc...
Article

Liver biopsy (transjugular)

Transjugular liver biopsy (TJLB) is an alternative to a percutaneous liver biopsy in patients with diffuse liver disease, coagulopathy and ascites. It is sometimes done in combination with a transjugular intrahepatic portosystemic shunt (TIPSS) or venography. Indications massive ascites coag...
Article

Gangrenous cholecystitis

Gangrenous cholecystitis is the most common complication of acute cholecystitis, affecting ~15% (range 2-30%) of patients.  Pathology Gangrenous cholecystitis occurs as a result of ischaemia with necrosis of the gallbladder wall 4.  Risk factors male increasing age delayed surgery cardiov...
Article

Pylephlebitis

Pylephlebitis, also known as ascending septic thrombophlebitis, is a thrombotic occlusion of the portal vein or its branches secondary to infection in regions that drain to this venous system. Pathology Aetiology septic focus: diverticulitis, appendicitis hypercoagulative status trauma abd...
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Variant hepatic arterial anatomy

Variation in hepatic arterial anatomy is seen in 40-45% of people. Classic branching of the common hepatic artery from the coeliac artery, and the proper hepatic artery into right and left hepatic arteries to supply the entire liver, is seen in 55-60% of the population.  In general, the common ...
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 I (caudate): the thumb...
Article

Hepatic adenoma

Hepatic adenoma is an uncommon benign liver tumour that is hormone induced. The tumours are usually solitary and have a predilection to haemorrhage and must be differentiated from other focal liver lesions. Epidemiology It is the most frequent hepatic tumour in young women who are on the oral ...
Article

Flash filling hepatic venous malformation

Flash filling hepatic venous malformations, also known as flash filling hepatic haemangiomas, are a type of atypical hepatic venous malformation (haemangioma), which due to its imaging features often raises the concern of a malignant process rather than a benign one.  Terminology It is importa...
Article

Abernethy malformation

Abernethy malformations are rare vascular anomalies of the splanchnic venous system. They consist of congenital portosystemic shunts and result from persistence of the embryonic vessels.  Epidemiology Type I malformations are thought to occur only in females, while type II have a male predomin...
Article

Oriental cholangiohepatitis

Oriental cholangiohepatitis, or recurrent pyogenic cholangiohepatitis, is a condition essentially found in Southeast Asia and is characterised by intra and extrahepatic bile duct strictures and dilatation with intraductal pigmented stone formation.  Diagnosis is made after exclusion of more com...
Article

Vicarious contrast material excretion

Vicarious contrast material excretion (VCME) defines excretion of water-soluble contrast material in a way other than via normal renal secretion.  The most common vicarious excretion of water-soluble contrast material is via the liver, resulting in increased bile density seen in the gallbladder...
Article

Amoebic hepatic abscess

Amoebic hepatic abscesses are a form of hepatic abscess resulting from Entamoeba histolytica infection. Clinical presentation Patients may experience general malaise or present with frank sepsis and right upper quadrant pain. Although the causative pathogen is found worldwide, it is endemic to...
Article

Pancreatic trauma

The pancreas is uncommonly injured in blunt trauma. However, pancreatic trauma has a high morbidity and mortality. Imaging features range between subtle to obvious. Epidemiology The pancreas is injured in ~7.5% (range 2-13%) of blunt trauma cases 1,3. Motor vehicle accidents account for the va...
Article

Pseudocirrhosis

Pseudocirrhosis is a complication of treated hepatic metastases, mainly those of breast cancer, which mimics liver cirrhosis radiologically. It has been reported in up to 50% of patients with breast cancer and liver metastases who underwent chemotherapy treatment 1. It is seen in the weeks or mo...
Article

Hyperechoic liver lesions

A hyperechoic liver lesion on ultrasound can arise from a number of entities, both benign and malignant. A benign hepatic haemangioma is the most common entity encountered, but in patients with atypical findings or a risk for malignancy, other entities must be considered. Benign hepatic haeman...
Article

Focussed Assessment with Sonography for Trauma (FAST) scan

Focussed Assessment with Sonography for Trauma (FAST) scan is a point-of-care ultrasound examination performed at the time of presentation of a trauma patient.  It is invariably performed by a clinician, who should be formally trained, and is considered as an 'extension' of the trauma clinical ...
Article

Bile duct dilatation (differential)

Bile duct dilatation can be due to several aetiologies. Clinical presentation Variable, depending on underlying cause, but usually: right upper quadrant pain jaundice Radiographic features Ultrasound Harmonic imaging is useful when assessing the biliary system, as it improves the clarity ...
Article

Post transplant lymphoproliferative / lymphoproliferation disorder (PTLD)

Post transplant lymphoproliferative/lymphoproliferation disorder (PTLD) is increasing in prevalence as the number and survival length of solid organ and bone-marrow transplant recipients also increases. It represents a variety of conditions varying from lymphoid hyperplasia to malignancy but is...
Article

IgG4-related disease

IgG4-related disease (IgG4-RD) is a systemic disease that is characterised by extensive IgG4-positive plasma cells and T-lymphocyte infiltration of various organs. Terminology This condition has been known by many other names in the past, such as IgG4-related sclerosing disease, IgG4-related s...
Article

Alpha-1 antitrypsin deficiency

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...
Article

AIDS cholangiopathy

AIDS cholangiopathy refers to an acalculous, secondary opportunistic cholangitis that occurs in AIDS patients as a result of immunosuppression.  Pathology Characterised by multiple irregular strictures essentially indistinguishable from primary sclerosing cholangitis (PSC). There are four path...
Article

Hepatic steatosis

Hepatic steatosis refers to an increase of intracellular fat in the liver. It is widely mischaracterised by both radiologists and sonographers that it represents 'fatty infiltration' however the fat is in the hepatocytes and not the extracellular matrix. On imaging grounds, it can broadly be div...
Article

Sonographic halo sign

Sonographic halo sign is used in a number of situations. They include: hypoechoic halo sign in liver metastases: used in hepatobiliary imaging, is a concerning feature for malignant lesion if the lesion is a hyperechoic liver lesion 1,2 ultrasound halo in angiolymphoid hyperplasia with eosinop...
Article

Infantile hepatic haemangioma

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. Terminology Those benign tumours were previous...

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