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
Radiogenomics
Radiogenomics denotes the relationship between the imaging features of a particular disease and various genetic or molecular features. The former is referred to as an imaging phenotype, whereas the later as genomic phenotype.
Radiogenomics, therefore, provides a tool for clinicians to correlat...
Article
Gadolinium
Gadolinium (chemical symbol Gd) is a metallic element that can be chelated into paramagnetic complexes for use as gadolinium contrast media.
Chemistry
Basic chemistry
Gadolinium is a silvery rare earth metal, and a member of the lanthanides, with the atomic number 64 and an atomic weight of 1...
Article
Zinc
Zinc (chemical symbol Zn) is a trace element with a key role as a constituent of enzymes (e.g. carbonic anhydrase), as a part of zinc finger proteins vital for the correct folding of macromolecules (such as DNA), and as an important cellular messenger 3.
Chemistry
Basic chemistry
Zinc is a tr...
Article
Heavy metals
Heavy metals is a vague term referring to metals of toxicologic significance. While historically this referred to metals of a high density/mass, such as those in the lanthanides and actinides (on the periodic table), it now encompasses a broad array of elements, including some metalloids (e.g. a...
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
Estimated glomerular filtration rate
The estimated glomerular filtration rate (eGFR) is widely used as a surrogate marker of renal function and is mathematically derived from the patient's serum creatinine, using their age, sex and ethnicity. There is some controversy over whether ethnicity should be included in the calculations.
...
Article
Eosinophilia
Eosinophilia is defined as an abnormally high level of eosinophils in the blood, this is usually defined as >500 cells/μL (normal eosinophil level: <450 cells/μL). Hypereosinophilia is defined as >1500 cells/μL and is usually due to hematological malignancy 1,2.
This article includes recommenda...
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
S100
S100 is a family of cytoplasmic calcium-binding proteins expressed in numerous cell lines which can be targeted by immunohistochemistry. Staining for S100 is helpful in characterizing a number of tumors, including malignant melanoma, glial tumors, neurogenic tumors (e.g. schwannomas and neurofib...
Article
Aneurysm
Aneurysms are focal abnormal dilatation of a blood vessel. They typically occur in arteries; venous aneurysms are rare. Aneurysms may also occur in the heart.
Pathology
Pathological types
true aneurysm
false aneurysm (or pseudoaneurysm)
Etiology
Atherosclerotic
atherosclerosis
Non-athero...
Article
Adenoma-carcinoma sequence
The adenoma-carcinoma sequence refers to a stepwise pattern of mutational activation of oncogenes (e.g. K-ras) and inactivation of tumor suppressor genes (e.g. p53) that results in cancer. An oncogene is a gene that has the potential to cause cancer. In tumor cells, these are often mutated or ex...
Article
Histology of blood vessels
Blood vessels, namely arteries and veins, are composed of endothelial cells, smooth muscle cells and extracellular matrix (including collagen and elastin). These are arranged into three concentric layers (or tunicae): intima, media and adventitia.
the intima (or tunica intima)
inner layer abut...
Article
Anemia
Anemia is the presence of reduced hemoglobin in the blood. Formally, the World Health Organizatiοn (WHO) defines anemia by the hemoglobin concentration in the blood according to age and sex 1:
adult men: <130 g/L
adult women: <120 g/L
Values for pregnant women and children are different.
Cli...
Article
Gliosis
Gliosis is a reactive process occurring after some time following most types of central nervous system injuries and is the result of focal proliferation of glial cells, particularly astrocytes.
Terminology
Although the terms astrocytic gliosis or astrocytosis are often used interchangeably wi...
Article
Skeletal muscle
Skeletal muscles, skeletal striated muscles or plainly muscles are integral to the locomotor system responsible for movements. The human body's musculoskeletal system has more than 600 muscles 1 making up around 40% of the body weight. They are heterogeneous and have different architectures and ...
Article
Hemoglobin
Hemoglobin (Hb) is the oxygen-carrying molecule in red blood cells.
Structure
Hemoglobin is a tetrameric protein molecule composed of four subunits. Each subunit consists of an iron-containing cyclic heme component linked to a polypeptide chain, the polypeptides are together known as globin. E...
Article
Naming of organisms
Occasionally, we will refer to lifeforms in an article or case, and we adhere to standard scientific convention when it comes to naming of organisms, as set down by the International Commission on Zoological Nomenclature (ICZN) 1. As per the standard binomial system, the genus and species of the...
Article
Zoonosis
A zoonosis (plural: zoonoses), also known as a zoonotic disease, is an infectious disease in humans (the host) for which another vertebrate animal can be the vector. Some zoonoses have an additional vector besides the vertebrate e.g. R. rickettsii is carried by ticks on mammals. Viruses, bacteri...
Article
Endometrial osseous metaplasia
Endometrial osseous metaplasia is a very rare pathological condition whereby there may be mature bone formation within the endometrium. This process may be a cause of menorrhagia and/or infertility.
Differential diagnosis
The common diagnostic mimics are iatrogenic endometrial gaseous foci (us...
Article
Metastatic axillary lymphadenopathy of unknown primary
Metastatic axillary lymphadenopathy of unknown primary can be a very challenging situation.
Pathology
Usual potential sites include:
occult breast cancer: the incidence of an axillary lymph node manifestation from an occult primary breast cancer is low, ranging from 0.3-0.8% of all patients ...
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