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 continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
More than 200 results
Article
Undifferentiated embryonal sarcoma of the liver
Undifferentiated embryonal sarcomas of the liver are rare, aggressive, and malignant liver tumors encountered in the pediatric population.
Epidemiology
Approximately 90% of cases occur in patients under 15 years of age, most commonly between 6 and 10 years of age, but some cases have been rep...
Article
Rosary sign (gallbladder)
The rosary sign is a CT finding in adenomyomatosis of the gallbladder. It is formed by the enhanced proliferative mucosal epithelium, with the intramural diverticula surrounded by the unenhanced hypertrophied muscle coat of the gallbladder. The rosary sign is similar to the pearl necklace sign.
Article
Mallory bodies
Mallory bodies are cytoplasmic eosinophilic inclusions in hepatocytes, associated with ballooning and inflammation, found in:
alcoholic fatty liver disease and hepatitis
non-alcoholic fatty liver disease
hepatocellular carcinoma (HCC)
primary biliary cholangitis (PBC)
cholestasis
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 urogenital system.
This article is a general discussion of the disease. Each organ system are discussed se...
Article
Pancreatic neoplasms
There are numerous primary pancreatic neoplasms, in part due to the mixed endocrine and exocrine components.
Classification
Classification based on function
exocrine: ~99% of all primary pancreatic neoplasms
pancreatic ductal adenocarcinoma (commonly known as pancreatic cancer) 90-95%
acin...
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
Tc99m mebrofenin
Tc99m-Mebrofenin: trimethyl bromo IDA, also known as TBIDA, or under the trade name Choletec, is a diagnostic radiopharmaceutical used in hepatobiliary imaging. It is one of the Tc99m IDA (iminodiacetic acid) analogs. It is taken up by hepatocytes through the same membrane transport mechanism as...
Article
Rolling stone sign
The rolling stone sign refers to the presence of gallstones within the gallbladder that are mobile when the patient moves.
Small gallstones can sometimes be difficult to diagnose due to the absence of posterior shadow artifact but the presence of a rolling stone sign increases the confidence of...
Article
Portal venous varix
A portal venous varix (plural: portal venous varices) refers to a segments of aneurysmal or variceal dilatation of the portal vein.
Epidemiology
Portal venous varices are extremely rare, representing only 3% of all aneurysms of the venous system. They are still, however, the most common viscer...
Article
Alpha-fetoprotein
Alpha-fetoprotein (AFP) is an important plasma protein synthesized by the yolk sac and fetal liver. In adults, its main utility is as a tumor marker, primarily for hepatocellular carcinoma or teratoma. Functionally it is the fetal homologue of albumin, i.e. it acts as a major carrier protein in ...
Article
Ascitic fluid cholesterol level
Ascitic fluid cholesterol level estimation is a simple and precise test for differentiating malignant ascites from non-malignant (cirrhotic) ascites 5-9.
Pathology
Ascites is the abnormal collection of fluid within the peritoneal cavity. Malignant ascites comprises ~10% and is usually seconda...
Article
Liver lesions
Liver lesions represent a heterogeneous group of pathology ranging from solitary benign lesions to multiple metastases from a variety of primary tumors.
Liver lesions may be infiltrative or have mass-effect, be solitary or multiple, benign or malignant.
Assessment of liver lesions takes into c...
Article
Tc99m IDA (iminodiacetic acid) analogs
Tc99m IDA (iminodiacetic acid) analogs are hepatobiliary agents in nuclear medicine, used in cholescintigraphy.
These include:
Tc99m-DISIDA: diisopropyl IDA, also known as Hepatolite
Tc99m-Mebrofenin: trimethyl bromo IDA, Choletec TM
Tc99m-PIPIDA: paraisopropyl iminodiacetic acid
The use of...
Article
Hepatic myelolipoma
Hepatic myelolipoma is a rare, benign fat-containing lesion of the liver, usually asymptomatic and found incidentally. Its diagnosis by imaging remains difficult because of a lack of pathognomonic signs. The definite diagnosis is by resection or biopsy.
Epidemiology
Hepatic myelolipomas are ...
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
Carcinogens
Carcinogens are substances known to cause cancer. They include:
Brain
vinyl chloride
Nasopharynx / nasal cavity
nickel
wood dust
chromium
Thyroid
ionizing radiation
Skin
arsenic
coal tars
polyaromatic hydrocarbons (PAH)
Lungs
arsenic
asbestos
chloromethyl ethers
chromium
coke-o...
Article
Biliary cystadenoma
Biliary cystadenomas, also known as mucinous cystic neoplasms of the liver, are uncommon benign cystic neoplasms.
Epidemiology
Biliary cystadenomas occur predominantly in middle-aged patients and are more common in women 1.
Clinical presentation
The clinical presentation of biliary cystadeno...
Article
Tensile gallbladder fundus sign
The tensile gallbladder fundus sign is positive when the gallbladder fundus is seen to bulge into, and distort, the anterior abdominal wall and is a feature of acute cholecystitis.
It is particularly useful as an early sign of the condition on CT as it has around a 75% sensitivity and 95% speci...
Article
Hepatic infarction
Hepatic infarction is an extremely rare situation because the liver has a dual blood supply from 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.
...
Article
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 ...
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