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.
318 results found
Article
Flail mandible
A flail mandible is an uncommon type of comminuted fracture through the mandibular symphysis and bilateral condyle and/or rami which can result in posterior displacement and internal rotation of the mandibular bodies, eversion of the angles of the mandible, and glossoptosis. Together with concom...
Article
Sessile
Sessile is a pathological term which is used for lesions that are attached by their base, that is they lack a stalk i.e. are not pedunculated. It is most commonly used for intraluminal polyps in the GI tract.
History and etymology
Sessile is derived from the Latin word "sessilis" which means s...
Article
Oncotype DX Breast Recurrence Score
Oncotype DX Breast Recurrence Score (Exact Sciences, USA) is a proprietary 21-gene expression assay that is prospectively validated and provides prognostic information on the 10-year risk of disease recurrence in estrogen receptor positive, lymph node-negative breast cancer patients 1. This gene...
Article
Citric acid cycle
The citric acid cycle, also known as the Krebs cycle or tricarboxylic acid cycle, is a central metabolic pathway in cells. It involves a series of chemical reactions that oxidize acetyl-CoA derived from carbohydrates, fats, and proteins to produce energy in the form of ATP and electron carriers ...
Article
Neuronal nuclear antigen (NeuN)
Neuronal nuclear antigen (NeuN) is a protein expressed in mature (post-mitotic) neurons and is commonly used as an immunohistochemical target to identify neuronal differentiation (e.g. in ganglioglioma and gangliocytomas).
It is primarily expressed in the nuclei of neurons with less pronounced...
Article
Grocott-Gomori methenamine silver stain
Grocott-Gomori methenamine silver (GMS) stain is a histological stain frequently used to screen specimens for fungal organisms. The procedure relies on the presence of polysaccharides along the fungal cell wall.
During the staining process, chromic acid is first applied to the specimen which ox...
Article
Bone grafting of reverse Hill-Sachs defects
Bone grafting of reverse Hill-Sachs defect is the surgical restoration of the humeral head due to compromised shoulder stability from large defects, which in patients without significant glenoid bone loss who have good bone stock, preserved articular cartilage, and humeral head defect between 20...
Article
Helicobacter pylori
Helicobacter pylori (H. pylori) is a gram-negative spiral flagellate microaerophilic bacterium found in the human gastric mucosa 1. It is classified as a Group I carcinogen and is considered necessary but insufficient alone to cause gastric adenocarcinoma. More often than not, it results in chro...
Article
Ahumada-Del Castillo syndrome
Ahumada-Del Castillo syndrome is a rare endocrine disorder affecting adult females, which is characterized by galactorrhea-amenorrhea not associated with pregnancy with estrogen deficiency and decreased urinary gonadotropin levels.
Clinical presentation
lactation not associated with breastfeed...
Article
Hartnup disease
Hartnup disease is an autosomal recessive disorder caused by the defective transport of neutral amino acids (monoamino-monocarboxylic acids) in the small intestine and kidneys.
Clinical presentation
pellagra-like skin eruptions
cerebellar ataxia
signs of spastic paraplegia with peripheral ne...
Article
Greater tubercle fracture of the shoulder
Greater tubercle/tuberosity fractures of the shoulder are a subtype of proximal humeral fractures.
Gross anatomy
The greater tubercle is the most lateral bony part of the shoulder. It is the site where three of the rotator cuffs insert to abduct or laterally rotate the shoulder joint (supraspi...
Article
Helium
Helium (chemical symbol He) is a noble gas and the least reactive of all the chemical elements. It is important as a cryogenic coolant in many MRI scanners.
Chemistry
Physical chemistry
Helium is an odorless colourless non-flammable gas. It has an atomic number 2 with a relative atomic weight...
Article
Hydrogen
Hydrogen (chemical symbol H) is one of the basic organic elements, and all organic compounds contain hydrogen. It is the commonest element in the visible universe comprising greater than 75% of all matter.
Chemistry
Physical chemistry
Hydrogen is an odorless, tasteless and colourless gas. It ...
Article
Carbon
Carbon (chemical symbol C) is one of the basic organic elements, and is a fundamental constituent of all organic molecules - and therefore all terrestrial life. Its unique versatility in forming different compounds comes from its ability to form multiple atomic bonds with itself.
Chemistry
Phy...
Article
Von Brunn nests of the bladder
Von Brunn nests are non-neoplastic reactive urothelial lesions that occur in the bladder. They represent clusters of urothelial cells found in the superficial lamina propria resulting from the invagination of the superficial urothelium.
Histologically, those nests generally show uniform size a...
Article
Perianal genital warts
Perianal genital warts, also known as condyloma acuminata (singular: condyloma acuminatum), are a complication of human papillomavirus (HPV) infection. They are diagnosed clinically and are usually painless and benign, but can rarely undergo malignant transformation into squamous cell carcinoma....
Article
Microcephaly with a simplified gyral pattern
Microcephaly with a simplified gyral pattern (MSG) is a congenital malformation characterized by microcephaly accompanied by a simplified gyral pattern. The term “simplified gyral pattern” often describes a reduced number of gyri and shallow sulci with a normal cortical thickness and architectur...
Article
Arias-Stella reaction
An Arias-Stella reaction is a common gynecological histological finding in curettage specimens of gestational endometrium describing a non-neoplastic lesion that is easily confused with uterine malignancy 1,2.
Pathology
An Arias-Stella reaction is due to hormonal hyperstimulation causing atypi...
Article
Extradural spinal cavernous malformation
Extradural spinal cavernous malformations, also known as extradural spinal cavernomas, are rare vascular malformations that occur in the spine.
This article specifically relates to extradural spinal cavernomas. For a general discussion of spinal cord cavernomas please refer to the article spin...
Article
Michaelis-Gutmann bodies
Michaeliis-Gutmann bodies are a histological feature characteristic of malakoplakia, typically seen in mid-stage disease 1,2.
They are 1–10 μm laminated or targetoid basophilic focal inclusions of iron and calcium salts seen on light microscopy. They are also periodic acid–Schiff, and diastase-...
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