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.
48 results found
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
cystic neuroendocrine tumor of the pancreas
diffuse pancreatic cysts
pancrea...
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 t...
Article
Splenic cyst
Splenic epithelial cysts, also known as splenic epidermoid cysts or primary splenic cysts, are unilocular fluid lesions with thin and smooth walls and no enhancement. They represent ~20% of cysts found in the spleen and are usually an innocuous incidental imaging finding.
Note that most (~80%) ...
Article
Medical devices in the abdomen and pelvis
Medical devices in the abdomen and pelvis are important to be recognized, just like medical devices of the chest. We often ignore these devices, considering them to be incidental and non-pathological, however it is essential to be aware of potential complications.
Gastrointestinal devices
tube...
Article
Periportal hyperechogenicity
Periportal hyperechogenicity can result from many causes including:
pneumobilia
cholecystitis
schistosomiasis of the portal region
recurrent pyogenic cholangitis (oriental)
inflammatory bowel disease: has been described to give "echo-rich" periportal cuffing 2
See also
periportal hypoech...
Article
Hepatic attenuation on CT
Hepatic attenuation on CT, reflected by Hounsfield values, depends on a combination of factors including the presence or absence, as well as the phase, of IV contrast administration.
Allowing for all these factors, the mean unenhanced attenuation value is around 55 HU 4.
Pathology
Several int...
Article
Pseudocirrhosis
Pseudocirrhosis is a radiological term used to convey the imaging findings of cirrhosis but emphasizes that it occurs in the setting of hepatic metastases. It is most commonly reported following chemotherapeutic treatment of breast cancer metastases, although it has also been reported before tre...
Article
Inflammatory myofibroblastic tumors of the liver
Inflammatory myofibroblastic tumors (IMTs) of the liver are extremely rare and account for just 0.7% of all hepatic lesions 1.
Refer to the article on inflammatory myofibroblastic tumors for a broad discussion.
Epidemiology
IMTs of the liver are usually frequent in young adults and Asian pe...
Article
Hypervascular liver lesions
Hypervascular liver lesions are findings that enhance more or similarly to the background hepatic parenchyma in the late arterial phase, on contrast-enhanced CT or MRI.
Differential diagnosis
Non-neoplastic
focal nodular hyperplasia (FNH)
bright arterial phase enhancement except central scar...
Article
Hemobilia
Hemobilia refers to the presence of blood in the biliary tree.
Clinical presentation
The classical Quincke triad, is seen with hemobilia in the context of hepatic arterial aneurysms, and consists of:
melena (i.e. upper gastrointestinal bleeding)
jaundice
abdominal pain
Pathology
Etiology
...
Article
Gallbladder folds
Gallbladder folds arise due to the gallbladder wall folding onto itself. They are thick, junctional in nature and incomplete or non-continuous in appearance.
The posterior wall is usually involved, however, anterior wall folds may also occur 1. The folding may produce a bizarre or unusual shap...
Article
Periportal lymphadenopathy (differential)
Periportal lymphadenopathy can be a common observation during imaging of the upper abdomen. What is considered the exact upper limit of normal has been variable 1,3 among different publications but with many authors suggesting a cut-off of around 10 mm in short axis diameter.
Pathology
Etiolog...
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 rarely occurs due to non-cardiac causes (e.g. ...
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 cholecystitis 11
postprandial physiological state (pseudothickening)
gallbladder o...
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
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
Splenomegaly
Splenomegaly refers to enlargement of the spleen. The upper limit of the normal adult splenic length is traditionally cited at 12 cm, but lengths upwards of 14 cm can be seen in normal, taller males 7.
Terminology
Massive splenomegaly is variably defined, including when the spleen is 5 standar...
Article
Retained gallstone
Retained gallstones, also called dropped or slipped gallstones, are common during a laparoscopic cholecystectomy, with a reported incidence of 0.1–20%, and occur when gallstones are inadvertently spilled into the peritoneal cavity.
Clinical presentation
Many cases of dropped gallstones will be...
Article
Bile duct dilatation
Bile duct dilatation refers to the dilatation of intrahepatic or extrahepatic bile ducts.
Clinical presentation
Variable, depending on the underlying cause, but usually:
right upper quadrant pain
jaundice
Radiographic features
Ultrasound
Harmonic imaging is useful when assessing the bilia...
Article
Ultrasound appearances of hepatic metastases
Ultrasound appearance of hepatic metastases can have bewildering variation, and the presence of hepatic steatosis can affect the sonographic appearance of liver lesions.
Radiographic features
Ultrasound
Patterns do exist between ultrasound appearance of the hepatic metastases and the likely p...