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.
719 results found
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 up to 20% of patients undergoing cholecystectomy for gallstone-related complaints 2.
Clinical prese...
Article
Mickey Mouse sign (disambiguation)
In medical imaging, a Mickey Mouse sign or appearance has been given to imaging features that mimic Mickey Mouse when viewed from the front. It has been described in the following:
anencephaly 2
progressive supranuclear palsy 1
synonymously with a finger in glove sign
the flared shape of the...
Article
Anastomosing hemangioma
Anastomosing hemangiomas are benign vascular neoplasms consisting of thin-walled anastomosing vessels. These lesions have been just added to the WHO classification of soft tissue tumors in 2020 as a separate entity 1-3
Epidemiology
Anastomosing hemangiomas are rare lesions with a wide range of...
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
Functional gallbladder disorder
Functional gallbladder dysfunction refers to biliary pain due to motility disturbance of the gallbladder without gallstones, biliary sludge, microlithiasis or microcrystals.
Terminology
The disorder has been or is known by several other names, including gallbladder dysfunction, gallbladder dys...
Article
Common hepatic duct
The common hepatic duct (CHD) is formed by the right and left hepatic ducts junction. It joins the cystic duct to form the common bile duct (CBD). It is approximately 4 cm long and 4 mm in diameter, typically.
Together with the cystic duct (laterally) and cystic artery (superiorly), they form ...
Article
Reye syndrome
Reye syndrome is a rare pediatric condition characterized by acute onset encephalopathy, severe vomiting and fatty liver failure. It typically presents in children recovering from a viral illness, most commonly influenza or chickenpox 1.
Epidemiology
Reye syndrome is usually seen between the ...
Article
Ascites
Ascites (hydroperitoneum is a rare synonym) is defined as an abnormal amount of intraperitoneal fluid.
Terminology
Ascites (plural is the same word) tends to be reserved for relatively sizable amounts of peritoneal fluid. The amount has not been defined formally. It is noted physiologically, h...
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
Intraductal papillary mucinous neoplasm
Intraductal papillary mucinous neoplasms or tumors (IPMNs or IMPTs) are epithelial pancreatic cystic tumors of mucin-producing cells that arise from the pancreatic ducts. They are most commonly seen in elderly patients.
On imaging, particularly MRCP, they are characterized by single or multipl...
Article
Alpha-1-antitrypsin deficiency
Alpha-1-antitrypsin (A1AT) deficiency is an autosomal codominant 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 panlobular emphysema and respirator...
Article
Transient hepatic echogenicity differences
Transient hepatic echogenicity differences (THED) are areas of differential enhancement of the liver parenchyma depicted with contrast-enhanced ultrasound (CEUS) using microbubble intravascular contrast agents. They are equivalent to transient hepatic attenuation differences (THAD) with contrast...
Article
Percutaneous cholecystostomy
Percutaneous cholecystostomy is the image-guided placement of a drainage catheter into the gallbladder lumen. This minimally invasive procedure can aid in patient stabilization in order to enable a more measured surgical approach with time for therapeutic planning.
A 2018 study demonstrated no ...
Article
Primary hyperoxaluria
Primary hyperoxaluria, also referred to 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 to secondary oxalosis for a discussion on the acquired form of hyperoxaluri...
Article
Focal nodular hyperplasia
Focal nodular hyperplasia (FNH) is a regenerative mass lesion of the liver and the second most common benign liver lesion (the most common is a hemangioma). Many focal nodular hyperplasias have characteristic radiographic features on multimodality imaging, but some lesions may be atypical in app...
Article
CEUS LI-RADS
The Contrast-enhanced Ultrasound Liver Imaging Reporting and Data System (CEUS LI-RADS) is a standardized classification system, algorithm, and terminology for diagnosing hepatocellular carcinoma (HCC) in high-risk patients using CEUS with blood-pool intravenous contrast agents.
The current ver...
Article
Gallbladder polyp
Gallbladder polyps are commonly occurring elevated lesions on the mucosal surface of the gallbladder. The vast majority are benign. They are best characterized on ultrasound as a non-shadowing endophytic growth into the gallbladder lumen.
Epidemiology
Gallbladder polyps are relatively frequen...
Article
Normal hepatobiliary imaging examples
This article lists examples of normal imaging of the liver and biliary tree and surrounding structures, divided by region and modality.
Liver
Plain radiographs
liver silhouette: example
Ultrasound
liver ultrasound
example 1 with shear wave elastography
liver Doppler ultrasound: example ne...
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
Choledochocele
Choledochoceles are a specific type of choledochal cyst (type III under the Todani classification system).
Epidemiology
Patients are usually adolescents and may present with a recurrent crisis of right upper quadrant pain, hyperamylasemia, or jaundice ref.
Pathology
In this type, there is ...
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