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.
16,862 results found
Article
Cystic lung disease
Cystic lung disease is an umbrella term used to group the conditions coursing with multiple lung cysts.
Clinical presentation
The clinical presentation is an important clue to the differential diagnosis of cystic lung diseases 12.
Diseases that present with insidious dyspnea or spontaneous p...
Article
Lymphoid interstitial pneumonia
Lymphoid interstitial pneumonia (LIP), also known as lymphocytic interstitial pneumonitis, is a benign lymphoproliferative disorder characterized by lymphocyte predominant infiltration of the lungs. It is classified as a subtype of interstitial lung disease. It also falls under the umbrella of n...
Article
Methylguanine-DNA methyltransferase (MGMT)
O6-Methylguanine-DNA methyltransferase (MGMT) is a DNA repair enzyme that is important in predicting the effects of alkylating chemotherapeutic agents (e.g. temozolomide) in the treatment of high-grade gliomas (astrocytomas and glioblastomas).
Mechanism of action
MGMT is an enzyme that removes...
Article
Temozolomide
Temozolomide is an oral chemotherapeutic drug primarily used in the treatment of astrocytomas, oligodendrogliomas and glioblastoma, often in conjunction with radiotherapy (Stupp protocol).
Mechanism of action
Temozolomide is an alkylating agent. It adds a methyl group to the purine bases of DN...
Article
Langerhans cell histiocytosis (skeletal manifestations)
The skeleton is the most commonly involved organ system in Langerhans cell histiocytosis (LCH) and is by far the most common location for single-lesion LCH, often referred to as eosinophilic granuloma (EG) (the terms are used interchangeably in this article). For a general discussion of this dis...
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
Inferior vena cava obstruction
Inferior vena cava obstruction, also known as inferior vena cava syndrome, refers to the clinical manifestations occurring as a result of any blockage in the inferior vena cava. It can occur due to external compression, thrombosis of inferior vena cava or iatrogenic placement of filters 1. Certa...
Article
COVID-19
For a quick reference guide, please see our COVID-19 summary article.
COVID-19 (coronavirus disease-2019) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a strain of coronavirus. The first cases were seen in Wuhan, China, in December 2019 before ...
Article
Niacin (vitamin B3) excess
In general taking large doses of water-soluble vitamins has not been found to have a deleterious clinical effect. However niacin (vitamin B3) excess can be problematic, usually when greater than 100 mg niacin is taken per day. To put this in context the recommended daily allowance (RDA) in the U...
Article
Hypervitaminosis D
Hypervitaminosis D (also known as vitamin D toxicity (VDT)) is very rare, and is usually secondary to exogenous administration of megadoses of vitamin D over long periods. Clinically it manifests as the clinical sequelae of chronic hypercalcemia.
Epidemiology
Incidence is unknown, however inte...
Article
Glucagon
Glucagon is a polypeptide hormone central to the regulation of glucose homeostasis, 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
Pulmonary infarction
Pulmonary infarction is one of the key complications of pulmonary embolism (PE).
Epidemiology
Pulmonary infarction occurs in the minority (10-15%) of patients with PE 1. Although in a necropsy study of those with lethal PE, 60% of cases developed infarction 2.
Historically it was thought tha...
Article
Nasopharyngeal carcinoma
Nasopharyngeal carcinomas (NPC) are the most common primary malignancy of the nasopharynx. They are of squamous cell origin. Some types are strongly associated with the Epstein-Barr virus (EBV).
Epidemiology
Nasopharyngeal carcinoma accounts for ~70% of all primary malignancies of the nasophar...
Article
Sliding sign
The sliding sign is a dynamic sonographic sign performed during transvaginal ultrasound (TVS) of women with suspected pelvic endometriosis. The loss of the normal sliding sign indicates pouch of Douglas (POD) obliteration due to adhesions and is suggestive of deep infiltrating endometriosis (DIE...
Article
Cardiac amyloidosis
Cardiac amyloidosis (plural: amyloidoses) is a significant source of morbidity among patients with systemic amyloidosis and is the most common cause of restrictive cardiomyopathy outside the tropics.
Pathology
Amyloidosis represents the extracellular deposition of insoluble fibrillar proteinac...
Article
Transthyretin amyloidosis
Transthyretin (ATTR) amyloidosis is a form of systemic amyloidosis characterized by the misfolding, aggregation and deposition of transthyretin-related (TTR) protein in various organs 1-6. This can occur in the following two forms namely in the setting of a genetically normal transthyretin-relat...
Article
Articular-sided rotator cuff tear
Articular-sided rotator cuff tears are partial-thickness rotator cuff tears extending from the articular side into the rotator cuff.
Epidemiology
Articular-sided rotator cuff tears commonly occur in athletes with overhead activity 1.
They are more common than bursal-sided tears and most commo...
Article
Placental site trophoblastic tumor
Placental site trophoblastic tumors (PSTT) are rare and one of the least common (~0.2% 7) forms of gestational trophoblastic disease.
Epidemiology
Placental site trophoblastic tumors typically occur in women of reproductive age with an average age of ~30 years. They may occur after a normal pr...
Article
Electrical impedance tomography
Electrical impedance tomography (EIT) is a type of imaging based on sending small amounts of electrical current across tissue (when used for medical imaging) and measuring conductivity.
Terminology
There are several ways in which the EIT signal can be generated and processed, and these are oft...
Article
Infratemporal fossa
The infratemporal fossa is a complex space of the face that lies posterolateral to the maxillary sinus, below the skull base, and between the pharyngeal sidewall and mandibular ramus. It overlaps with the masticator space and prestyloid parapharyngeal space.
Gross anatomy
The infratemporal fos...
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