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
Thyroseq
Thyroseq® is an expanded gene classifier test designed for further evaluation of indeterminate thyroid nodules on fine needle aspiration (FNA). In particular, it is designed to further evaluate nodules that show atypia of undetermined significance/follicular lesion of undetermined significance (...
Article
Erythrocyte sedimentation rate
Erythrocyte sedimentation rate (ESR) is a non-specific marker of acute inflammation which is seen in a very wide spectrum of pathologies. It has been sidelined by the use of C-reactive protein and other acute phase markers but it still has an important role to play in the management of some cond...
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
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 odourless, tasteless and colourless gas. It...
Article
Psammoma bodies
Psammoma bodies are round microscopic calcific collections. It is a form of dystrophic calcification. Necrotic cells form the focus for surrounding calcific deposition. They have a lamellated concentric calcified structure, sometimes large enough to be seen on CT.
Psammoma bodies are found in ...
Article
Cortical laminar necrosis
Cortical laminar necrosis, also known as pseudolaminar necrosis, is necrosis of neurones in the cortex of the brain in situations when the supply of oxygen and glucose is inadequate to meet regional demands. This is often encountered in cardiac arrest, global hypoxia and hypoglycaemia.
It shoul...
Article
Desmoplasia
Desmoplasia, also known as a desmoplastic reaction, is the term used by pathologists to refer to the growth of fibrous tissue around disease, usually cancer. However in dermatopathology, desmoplasia may also be seen with benign, as well as malignant, conditions.
Terminology
Pathologists prefer...
Article
DNA
DNA (deoxyribonucleic acid) is a nucleic acid that encodes the genetic information (genome) necessary for RNA (ribonucleic acid) transcription (transcriptome) and protein synthesis (proteome) 1. It is contained in the nucleus of eukaryotic cells in the form of chromatin or chromosomes 7,8.
Mole...
Article
PSA density
The PSA density (PSAD) is a calculation performed at diagnosis and is the serum prostate specific antigen (PSA) level (ng/mL) divided by the volume of the prostate gland (mL), resulting in a value with the units, ng/mL2 1. Prostate volume is calculated from TRUS measurements 2,3.
Alternatively...
Article
Glucagon
Glucagon is a polypeptide hormone central to the regulation of glucose homoeostasis, acting as an antagonist to insulin. In imaging, it is used as an antiperistaltic agent in GI studies, although its clinical efficacy is controversial.
Structure
Glucagon is a 29-amino acid polypeptide hormone...
Article
Lipoma
Lipomas are benign tumours composed of mature adipocytes. They are the most common soft tissue tumour, seen in ~2% of the population.
Epidemiology
Patients typically present in adulthood (5th-7th decades).
Associations
In some cases, multiple lipomas are associated with syndromes and other ...
Article
Human coronavirus
The human coronaviruses (hCoVs), members of the family Coronaviridae, are enveloped RNA viruses that affect humans, mammals and birds, causing both acute and chronic illnesses.
Four of the seven known human coronaviruses usually cause a mild coryzal illness only, these are HKU1, NL63, OC43, and...
Article
Pleomorphic adenoma of the salivary glands
Pleomorphic adenomas of the salivary glands, also known as benign mixed tumours (see below), are the most common salivary gland tumours. The salivary glands are the most common site of pleomorphic adenomas.
On imaging, they commonly present as well-circumscribed rounded masses, most commonly lo...
Article
Faecal calprotectin
Faecal calprotectin (FCAL) is a protein marker of gut inflammation. It is used as a diagnostic tool and marker of disease activity for Crohn disease and ulcerative colitis.
Biochemistry
Calprotectin is a protein complex from the S-100 family, which is formed of three polypeptide chains, two he...
Article
Non-pulsatile tinnitus
Non-pulsatile tinnitus is a form of tinnitus where there is a continuous ringing sensation of the ears. It is thought to have a considerable subjective component in many individuals.
Pathology
Many factors have been postulated, inclusive of 1-5:
cerumen impaction
middle ear infection
medica...
Article
Cobalt
Cobalt (chemical symbol Co) is an essential trace element. Its most important function in humans is as the active metal atomic centre of vitamin B12.
Chemistry
Basic chemistry
Cobalt is a shiny grey-silvery transition metal with an atomic number 27 and an atomic weight of 58.93 Daltons (Da). ...
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
Inflammation
Inflammation is a response to noxious stimuli that can be acute or chronic.
The cardinal signs of inflammation include:
heat (calor)
redness (rubor)
swelling (tumour)
pain (dolour)
loss of tissue function (functio laesa)
Subtypes
Acute Inflammation
Acute inflammation occurs within the f...
Article
Tumour spread through air spaces
Tumour spread through air spaces (STAS) is a pattern of invasion in lung adenocarcinoma. According to the 2015 WHO classification, tumour spread through air spaces is defined as “micropapillary clusters, solid nests, or single cells spreading within air spaces beyond the edge of the main tumour”...
Article
Biotin
Biotin, less commonly known as vitamin B7, and previously known as vitamin H or coenzyme R, is a water-soluble vitamin, part of the vitamin B complex, and a coenzyme for many reactions, including gluconeogenesis and the synthesis of fatty acids and amino acids.
Biotin deficiency is very rare.
...
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