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.
16,879 results found
Article
Owl-eyes sign (spinal cord)
The owl-eyes sign, also known as snake-eyes sign or fried-eggs sign, represents bilaterally symmetric circular to ovoid foci of high T2-weighted signals in the anterior horn cells of the spinal cord and is seen on axial MR imaging. The sagittal corollary is a "pencil-like" vertical linear high T...
Article
Megalencephaly-capillary malformation syndrome
Megalencephaly-capillary malformation (MCAP) syndrome, also known as macrocephaly-capillary malformation syndrome, is a rare and well described genetic disorder caused by somatic mutations in the PIK3CA gene on chromosome 3q26 and characterized by early brain overgrowth and body morphogenesis an...
Article
Bronchial artery
The bronchial arteries are the major supply of high-pressure oxygenated blood to the supporting structures of the lung, including the pulmonary arteries, but contribute only 1% of total lung blood flow. Blood in the bronchial circulation does not take part in gas exchange unless there is patholo...
Article
Tarsal bones
The tarsal bones are the seven bones of the foot excluding the metatarsals and phalanges. They are collectively known as the tarsus. The seven bones are:
talus
calcaneus
navicular
cuboid
lateral cuneiform
intermediate cuneiform
medial cuneiform
There are several mnemonics for the tarsals.
Article
Perivascular epithelioid cell tumors (PEComas)
Perivascular epithelioid cells tumors (PEComas) are a group of related mesenchymal tumors and tumor-like conditions found in many locations. This group includes:
angiomyolipoma (AML)
clear cell "sugar" tumor of the lung
lymphangioleiomyomatosis (LAM)
clear cell myomelanocytic tumor (CCMMT)
...
Article
Erosive arthritis (differential)
Erosive arthritis has a broad differential:
erosive osteoarthritis
clinically an acute inflammatory attacks (swelling, erythema, pain) in postmenopausal women
typically the interphalangeal joints, 1st carpometacarpal joint 6, but not the metacarpophalangeal (MCP) joints and large joints
clas...
Article
Aberrant right subclavian artery
Aberrant right subclavian arteries (ARSA), also known as arteria lusoria, are among the commonest aortic arch anomalies.
Epidemiology
The estimated incidence is 0.5-2% 1.
Associations
as can be expected from the embryological development of the artery, the right recurrent laryngeal nerve...
Article
Bronchial atresia
Bronchial atresia is a developmental anomaly characterized by focal obliteration of the proximal segment of a bronchus associated with hyperinflation of the distal lung.
On imaging, it commonly presents as a proximal focal tubular-shaped opacity radiating from the hilum associated with a dista...
Article
Asymmetric ventriculomegaly, interhemispheric cyst and dysgenesis of the corpus callosum (AVID)
Asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum (AVID) is a triad of congenital cerebral anomalies.
Radiographic features
markedly asymmetric enlargement of the lateral ventricles may be the initial finding on routine fetal morphology ultrasound.
inte...
Article
Inferior olivary nucleus
The inferior olivary nuclei (or ION) are two C-shaped nuclei located within the medulla oblongata, implicated in motor coordination.
Gross anatomy
The inferior olivary nuclei are located in the superior medulla, just below the pons. They are an irregular mass of crenated C-shaped grey matter, ...
Article
Eyelid
The eyelids cover the eyes, with an upper and lower eyelid on each side, and are covered in front with loose skin and behind with adherent conjunctiva. The lower lids possess very little mobility; the upper eyelid is elevated by levator palpebrae superioris muscle fibers and the lids are closed ...
Article
Hypervascular splenic lesions
Hypervascular splenic lesions are findings that enhance more or similarly to the background splenic parenchyma on late arterial phase, on contrast-enhanced CT or MRI.
Vascular
mycotic aneurysm
Neoplastic
splenic hemangioma 2
most common primary benign neoplasm of the spleen
second most com...
Article
Tam o' Shanter sign (skull)
This imaging sign is named after the Tam o' Shanter, a Scottish hat, named after the character in Robert Burns's 1 poem of the same name. The appearances of advanced Paget disease of the skull are similar in appearance to the hat.
Paget involvement of the skull, with widening of the diploic sp...
Article
Brachiocephalic trunk
The brachiocephalic trunk (BCT) (also known as the brachiocephalic artery, and previously as the innominate artery) is the first branch of the aortic arch and supplies the head, neck and right arm.
Terminology
Although sometimes described as such, the brachiocephalic trunk is not one of the gr...
Article
Lateral thoracic meningocele
Lateral thoracic meningoceles are a type of spinal meningocele.
Pathology
As with any meningocele, it results from herniation of the meninges through a foramen or a defect in the vertebral column.
Associations
They are typically associated with neurofibromatosis type I but can rarely occur ...
Article
Transjugular intrahepatic portosystemic shunt
Transjugular intrahepatic portosystemic shunt (TIPS or TIPSS) is a treatment for portal hypertension in which direct communication is formed between a hepatic vein and a branch of the portal vein, thus allowing some proportion of portal flow to bypass the liver. The target portosystemic gradient...
Article
Gracilis muscle
The gracilis muscle is the most superficial muscle in the medial compartment of the thigh and descends almost vertically down the medial side of the thigh.
Summary
origin: a line on the external surfaces of the body of the pubis, inferior pubic ramus, and the ramus of the ischium
insertion: a...
Article
Target sign (choledocholithiasis)
The target sign of choledocholithiasis is a finding seen on contrast-enhanced CT and comprises:
central density within the bile duct: stone
surrounding low density: bile or mucosa
Article
Pseudodacryocystitis
Pseudodacryocystitis refers to anterior ethmoidal sinus inflammation, usually with superimposed infection, extending into the adjacent lacrimal sac region and consequently giving a clinical presentation similar to dacryocystitis.
Unlike dacryocystitis, clinical irrigation typically shows patenc...
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. Diseases in this group include:
congenital hepatic fibrosis
autosomal dominant polycystic disease
biliary hamartomas
Caroli d...
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