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
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
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
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 ...
Article
Hypoglossal nerve palsy
Hypoglossal nerve palsies, or twelfth nerve palsies, result in weakness of the muscles supplied by the hypoglossal nerve, namely the intrinsic and extrinsic tongue muscles, except for palatoglossus.
Clinical presentation
The hypoglossal nucleus receives a major component of contralateral corti...
Article
Klebsiella
Klebsiella is a genus of Gram-negative, oxidase-negative, rod-shaped bacteria, which is relatively commonly encountered in the healthcare environment. It has numerous species, including K. pneumoniae, K. aerogenes, and K. rhinoscleromatis 1. Klebsiella may cause a range of infections, most commo...
Article
Strain elastography
Strain elastography (also known as tissue strain elastography/static elastography/compression elastography) is a developing form of ultrasound that assesses tissues' macroscopic structure through the strain modulus. This is different from normal B-mode grayscale ultrasound which characterizes a ...
Article
Corpus callosum
The corpus callosum (plural: corpora callosa) is the largest of the commissural fibers, linking the cerebral cortex of the left and right cerebral hemispheres. It is the largest white matter tract in the brain.
Summary
located inferior to the cerebral cortices, and superior to the thalamus
co...
Article
Protoplasmic astrocytoma (historical)
Protoplasmic astrocytoma is a historical term previously applied to an uncommon variant of diffuse adult-type astrocytomas.
Terminology
The term was removed in the updated 4th edition (2016) of the WHO classification of CNS tumors, with these tumors folded into what is now referred to as astro...
Article
Idiopathic interstitial pneumonias: HRCT chest approach
The approach to HRCT chest in patients with suspected idiopathic interstitial pneumonia (IIP) is with the aim to:
make sure an appropriate study requested i.e. HRCT chest with optimal individually adjusted protocol and ensure adequacy of the HRCT chest quality (see imaging protocol below)
meti...
Article
Duchenne muscular dystrophy
Duchenne muscular dystrophy (DMD) is a dystrophinopathy and the most common muscular dystrophy.
Epidemiology
Duchenne muscular dystrophy has an incidence of 1 in 3500 to 5000 males 1,2. The condition is extremely rare in females due to its inheritance pattern, as discussed below 1.
Clinical p...
Article
Facial fractures
Facial fractures are commonly caused by blunt or penetrating trauma at moderate or high levels of force. Such injuries may be sustained during a fall, physical assault, motor vehicle collision, or gunshot wound. The facial bones are thin and relatively fragile, making them susceptible to injury....
Article
Asymmetry of the lateral ventricles
The lateral ventricles occasionally show small side to side differences in size on CT or MRI of the brain. This asymmetry of the lateral ventricles (ALV) is an anatomic variant in most cases.
Epidemiology
The prevalence of asymmetry in lateral ventricle size in those without evidence of underl...
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