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
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
Law of Bergonié and Tribondeau
The law of Bergonie and Tribondeau is that the radiosensitivity of a biological tissue is directly proportional to the mitotic activity and inversely proportional to the degree of differentiation of its cells. This law underpins the field of radiation-oncology, although such a general law may no...
Article
Braxton Hicks contractions
Braxton Hicks contractions, also known as practice contractions or false labor, are physiological contractions of myometrium that occur in pregnancy. They are often sporadic and start by ~6 weeks.
Radiographic features
Antenatal ultrasound
It may be seen as a transient change in myometrial th...
Article
Excessive dynamic airway collapse
Excessive dynamic airway collapse (EDAC) refers to a dynamic form of central airway obstruction characterized by a decrease of ≥50% (some publications suggest >70% ref) in the cross-sectional area of the tracheobronchial lumen.
Terminology
Some authors consider an overlap with tracheomalacia, ...
Article
Tumor pseudoprogression (lung cancer)
Radiologic tumor pseudoprogression on imaging denotes an imaging appearance of tumor response where the tumor first exhibits findings suggestive of progression (i.e. growth, new lesions). However, during sustained therapy, response is eventually demonstrated 1.
Epidemiology
With the advent of ...
Article
Common hepatic duct
The common hepatic duct (CHD) is formed by the right and left hepatic ducts junction. It joins the cystic duct to form the common bile duct (CBD). It is approximately 4 cm long and 4 mm in diameter, typically.
Together with the cystic duct (laterally) and cystic artery (superiorly), they form ...
Article
Decompressive craniectomy
Decompressive craniectomies are craniectomies performed to relieve raised intracranial pressure, most commonly in the setting of florid cerebral edema following cranial trauma or swelling following infarction 1.
History
Craniectomies for the treatment of cranial trauma date back to at least 10...
Article
Hemiplegic migraine
Hemiplegic migraines are an uncommon type of migraine with aura wherein patients present with usually reversible motor weakness, typically unilateral. They can be challenging to distinguish from seizure with Todd paresis or ischemic stroke, even with the benefit of MRI 1.
Epidemiology
Compared...
Article
Artificial intelligence
Artificial intelligence (AI) has been defined by some as the "branch of computer science dealing with the simulation of intelligent behavior in computers" 1, however, the precise definition is a matter of debate among experts.
An alternative definition is the branch of computer science dedicat...
Article
Osteonecrosis of the femoral head
Osteonecrosis of the femoral head, previously known as avascular necrosis (AVN) of the hip, is the most common site for osteonecrosis, presumably due to a combination of precarious blood supply and high loading when standing.
Idiopathic osteonecrosis of the femoral head epiphysis in children (...
Article
Meningeal hemangiopericytoma (historical)
Hemangiopericytomas of the meninges are rare tumors of the meninges, now considered to be an aggressive form of solitary fibrous tumors of the dura. They often present as large and locally aggressive dural masses, frequently extending through the skull vault. They are difficult to distinguish on...
Article
Systemic lupus erythematosus (CNS manifestations)
Central nervous system manifestations of systemic lupus erythematosus (CNS lupus), also known as neuropsychiatric systemic lupus erythematosus (NPSLE), describe a very diverse range of neuropsychiatric manifestations that are secondary to systemic lupus erythematosus (SLE) in the central nervous...
Article
Medulloepithelioma of the brain
Medulloepitheliomas of the brain are rare, highly malignant, primitive embryonic tumors derived from the primitive medullary plate and neural tube. These tumors, once considered distinct entities, are now thought to be a pattern of embryonal tumors with multilayered rosettes. Please refer to tha...
Article
Anal atresia
Anal atresia, or imperforate anus, refers to a spectrum of anorectal abnormalities ranging from a membranous separation to complete absence of the anus.
Epidemiology
The estimated incidence is 1 in 5000 live births.
Associations
There are frequent associations with other congenital abnormali...
Article
Small bowel mesentery internal hernia
Small bowel mesentery internal hernias (alternative plural: herniae) are a form of internal bowel herniation involving protrusions of viscera through defects in the peritoneum or bowel mesentery.
Epidemiology
This type of internal herniation is more often seen in neonates than in adults ref.
...
Article
Computer aided diagnosis
Computer aided diagnosis (CAD) is the use of a computer generated output as an assisting tool for a clinician to make a diagnosis. It is different from automated computer diagnosis, in which the end diagnosis is based on a computer algorithm only.
As an early form of artificial intelligence, co...
Article
Cytotoxic lesions of the corpus callosum (CLOCCs)
Cytotoxic lesions of the corpus callosum (CLOCCs) represent a collection of disparate conditions that can cause signal change in the corpus callosum, usually involving the splenium.
Terminology
The term cytotoxic lesions of the corpus callosum (CLOCCs) has been proposed 12 as a more precise d...
Article
Inflammatory leiomyosarcoma
Inflammatory leiomyosarcomas are malignant tumors with smooth muscle differentiation and a prominent inflammatory infiltrate that were recognized as a distinct entity by the WHO in 2020 1-3.
Epidemiology
Inflammatory leiomyosarcomas are very rare lesions with most cases seen in adults with a p...
Article
Flow-diverter stent
Flow-diverter stents are important devices in the management of intracranial aneurysms in both acute and elective settings, especially ones that are large, broad-necked, or fusiform.
Complications
Understanding the complication rates is important in obtaining informed consent from patients. In...
Article
Chemical shift artifact
Chemical shift artifact or misregistration is a type of MRI artifact. It is a common finding on some MRI sequences and used in magnetic resonance spectroscopy (MRS). This artifact occurs in the frequency-encoding direction and is due to spatial misregistration of fat and water molecules.
Chemi...