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.
16,873 results found
Article
Positive ulnar variance
Positive ulnar variance describes where the distal articular surface of the ulna is more than 2.5 mm distal to the articular surface of the radius.
It plays important role in wrist pathology such as ulnar impaction syndromes and thinning of the triangular fibrocartilage complex.
Radiographic ...
Article
Dinner fork deformity (wrist)
A dinner fork deformity, also known as a bayonet deformity, occurs as the result of a malunited distal radial fracture, usually a Colles fracture. The distal fragment is dorsally angulated, displaced and often also impacted. The term is descriptive, as the lateral view of the wrist is similar to...
Article
Gastric diverticulum
Gastric diverticula are sac-like outpouchings that most commonly originate from the posterior surface of the gastric fundus. They are the least common of the gastrointestinal diverticula.
Epidemiology
Gastric diverticula are rare and commonly detected incidentally. The incidence varies from 0...
Article
Medical abbreviations and acronyms (F)
This article contains a list of commonly used medical abbreviations and acronyms that start with the letter F and may be encountered in medicine and radiology (please keep both the main list and any sublists in alphabetic order).
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q...
Article
Calcarine fissure
The calcarine fissure, or calcarine sulcus, is located on the medial surface of the occipital lobe and divides the visual cortex (a.k.a. calcarine cortex) into two.
The fissure is variable in course (figure 1), but is generally oriented horizontally, anteriorly joining the parieto-occipital fi...
Article
Brachial plexus root subdivisions (mnemonic)
Mnemonics for brachial plexus root subdivisions include:
Rad Techs Drink Cold Beer
Robbie T Drinks Cold Beer
Rugby Teams Drink Cold Beers
Reach To Drink Cold Beer
Read That Damn Cadaver Book
Really Tired, Don't Care Now (nerve instead of branch)
Red Toucans Don't Come Back
Mnemonic
Whe...
Article
Pulmonary cavity
A pulmonary cavity is a collection of gas and/or fluid enclosed by a thick and often irregular wall which usually occurs when central necrotic tissue is expelled via a bronchial connection. Cavities may be single or multiple and can be isolated or associated with lung disease 12.
Terminology
P...
Article
Splenic artery embolization
Splenic artery embolization is an endovascular technique for treatment of splenic and splenic artery pathology as an alternative to splenic artery ligation or splenectomy. It often results in successfully treating the underlying pathology, while maintaining at least partial splenic function.
I...
Article
Tibiotalar angle
The tibiotalar angle is between the anatomic axis of the tibia and the superior articular surface of the talar dome. Differently from the talar tilt, the tibiotalar angle uses the tibial longitudinal axis instead of the distal articular surface as a tibial reference point.
Usage
The tibiotalar...
Article
Susceptibility vessel sign
The susceptibility vessel sign is a radiological sign appreciated on susceptibility-sensitive MRI brain sequences that is described in patients with acute ischemic stroke. It correlates well with the hyperdense vessel sign (e.g. hyperdense MCA sign) that may be seen on CT brain, but is considere...
Article
Acromial types
The shape of the acromion had been initially divided into three types (which was known as the Bigliani classification) 3, to which a fourth has been added 2. They are used as a standardized way of describing the acromion, as well as predicting to a degree the incidence of impingement.
Classifi...
Article
Osteochondroma
Osteochondromas are a relatively common imaging finding, accounting for 10-15% of all bone tumors and ~35% of all benign bone tumors. Although usually thought of as a benign bone tumor, they may be thought of as a developmental anomaly. They are frequently asymptomatic and have very low malignan...
Article
Clustering
Clustering, also known as cluster analysis, is a machine learning technique designed to group similar data points together. Since the data points do not necessarily have to be labeled, clustering is an example of unsupervised learning. Clustering in machine learning should not be confused with d...
Article
Godtfredsen syndrome
Godtfredsen syndrome, also known as clival (clivus) syndrome, is a rare syndrome of abducens and hypoglossal nerve palsies that localizes to a clival mass.
Clinical presentation
The classic clinical presentation includes 1-3:
abducens nerve palsy: diplopia worse when horizontal gaze is direct...
Article
Clivus
The clivus (of Blumenbach) is the sloping midline surface of the skull base anterior to the foramen magnum and posterior to the dorsum sellae 1.
Gross anatomy
Specifically, the clivus is formed by the sphenoid body and the basiocciput, which join at the spheno-occipital synchondrosis. At the c...
Article
Abducens nerve palsy
Abducens nerve palsy, or sixth nerve palsy, results in weakness of the ipsilateral lateral rectus muscle.
Clinical presentation
Patients present with horizontal diplopia with an inability to abduct the ipsilateral eye, thereby resulting in an esotropia (nasal deviation of the eye).
Pathology
...
Article
Pneumatosis coli
Pneumatosis coli is a descriptive sign presenting radiographically as intramural gas limited to the colonic wall.
Terminology
There are different terminologies in the medical literature, such as pneumatosis intestinalis, pneumatosis coli, and pneumatosis cystoides intestinalis. Pneumatosis in...
Article
Thoracic actinomycosis infection
Thoracic actinomycosis refers to an uncommon indolent infection caused principally by the genus Actinomyces (higher prokaryotic bacteria belonging to the family Actinomyceataceae).
Epidemiology
While it is rare in general, the thoracic form actinomycosis constitutes ∼15% of the total burden of...
Article
Gadolinium contrast agents
Gadolinium-based contrast media (GBCM), gadolinium-based contrast agents (GBCAs), or simply gadolinium contrast agents, are molecular complexes containing the rare earth metal gadolinium, chelated to a carrier ligand. They are a type of paramagnetic contrast agent, which are the primary class of...
Article
Empyema vs pleural effusion
An empyema can resemble a pleural effusion and can mimic a peripheral pulmonary abscess. Features that help distinguish a pleural effusion from an empyema include:
Shape and location
Empyemas usually:
form an obtuse angle with the chest wall
unilateral or markedly asymmetric whereas pleural ...
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