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.
16,904 results found
Article
Pulmonary cavity
A pulmonary cavity is a collection of gas and/or fluid enclosed by a thick and often irregular wall which usually occurs when central necrotic tissue is expelled via a bronchial connection. Cavities may be single or multiple and can be isolated or associated with lung disease 12.
Terminology
P...
Article
Dysgenesis of the corpus callosum
Dysgenesis of the corpus callosum may be complete (agenesis) or partial (dysgenesis) and represents an in utero developmental anomaly. It can be divided into:
primary agenesis: corpus callosum never forms
secondary dysgenesis: corpus callosum forms normally and is subsequently destroyed
Epide...
Article
Guillain-Barré syndrome
Guillain-Barré syndrome (GBS) is a heterogeneous group of autoimmune polyradiculopathies, involving sensory, motor, and autonomic nerves. It is the most common cause of rapidly progressive flaccid paralysis. It is believed to be one of a number of related conditions, sharing a similar underlying...
Article
Canal wall up mastoidectomy
A canal wall up mastoidectomy is one of the types of mastoidectomies that can be performed. This involves exenteration of the mastoid air cells with preservation of the posterior wall of the external auditory canal, creating a mastoid bowl or cavity.
This procedure includes removal of Koerner...
Article
Desmoplastic fibroma
Desmoplastic fibromas are extremely rare bone tumors that do not metastasize but may be locally aggressive. They are considered to be a bony counterpart of soft tissue desmoid tumors and are histologically identical.
Epidemiology
Desmoplastic fibroma of bone is rare and mostly found in young ...
Article
Panoramic ultrasound
Panoramic ultrasound is an ultrasound technique which stitches multiple B-mode images together to create a single composite image with an increased field of view (FOV) 1.
Clinical Applications
It is useful in the evaluation of masses/objects of interest which are larger than the typical FOV 1....
Article
Abdominoperineal resection
Abdominoperineal resection (APR), or abdominoperineal excision of the rectum (APER), is a type of surgery for the treatment of predominantly low rectal carcinoma in which the sigmoid colon, rectum, and anal canal are removed leaving behind a permanent colostomy.
Indications
Most commonly in pa...
Article
Elbow
The elbow is a complex synovial joint formed by the articulations of the humerus, the radius, and the ulna.
Gross anatomy
Articulations
The elbow joint is made up of three articulations 2,3:
radiohumeral: capitellum of the humerus with the radial head
ulnohumeral: trochlea of the humerus w...
Article
Granulomatosis with polyangiitis
Granulomatosis with polyangiitis (GPA), previously known as Wegener granulomatosis, is a multisystem necrotizing non-caseating granulomatous c-ANCA positive vasculitis affecting small to medium-sized arteries, capillaries, and veins, with a predilection for the respiratory system and kidneys.
T...
Article
Agatston score
Agatston score is a semi-automated tool to calculate a score based on the extent of coronary artery calcification detected by an unenhanced low-dose CT scan, which is routinely performed in patients undergoing cardiac CT. Due to an extensive body of research, allows for early risk stratification...
Article
Aliasing phenomenon (ultrasound)
Aliasing is a phenomenon inherent to Doppler modalities which utilize intermittent sampling in which an insufficient sampling rate results in an inability to record direction and velocity accurately.
Physics
Unlike continuous wave Doppler, pulsed wave and color flow Doppler modalities alterna...
Article
Left hemicolectomy
Left hemicolectomy is a surgical procedure in which splenic flexure, descending colon, and a portion of the sigmoid colon are removed for radical treatment of various pathologies affecting the descending colon.
Indications
colon cancer
inflammatory bowel disease
isolated left diverticular di...
Article
Pituitary stalk interruption syndrome
Pituitary stalk interruption syndrome, also known as pituitary stalk transection syndrome, is a syndrome characterized by an absent or hypoplastic anterior pituitary gland, thin or absent infundibulum, and ectopic posterior pituitary location.
Epidemiology
Pituitary stalk interruption syndrome...
Article
Ectopic posterior pituitary
An ectopic posterior pituitary reflects a disruption of normal embryogenesis of the posterior pituitary and is one of the more common causes of pituitary dwarfism. Although it can be an isolated abnormality, numerous other congenital central nervous system malformations have been identified. Whe...
Article
Subependymal grey matter heterotopia
Subependymal grey matter heterotopia, also known as periventricular heterotopia, is the most common form of grey matter heterotopia and is characterized by nodules of grey matter located immediately beneath the ependyma of the lateral ventricles. It can be divided according to morphology into 2:...
Article
Pulse repetition frequency
Pulse repetition frequency (PRF) indicates the number of ultrasound pulses emitted by the transducer over a designated period of time. It is typically measured as pulses per second or hertz (Hz). In medical ultrasound the typically used range of PRF varies between 1 and 10 kHz 1. PRF is defined ...
Article
Genant classification of vertebral fractures
The Genant classification of vertebral fractures is based on the vertebral shape, with respect to vertebral height loss involving the anterior, posterior, and/or middle vertebral body as seen on lateral radiographs of the thoracic or lumbar spine 1.
Usage
The Genant classification has been use...
Article
Branches of the external carotid artery (mnemonic)
Mnemonics for the branches of the external carotid artery abound. A few colorful examples include:
Some American Ladies Found Our Pyramids Most Satisfactory
Some Anatomists Like Freaking Out Poor Medical Students
She Always Likes Friends Over Papa, Mama, and Sister
There are many many many ...
Article
Glomerulocystic kidney disease
Glomerulocystic kidney disease (GCKD) is a rare cystic kidney disease.
Epidemiology
Associations
Following syndromic associations have been proposed 4:
Down syndrome
asplenia with cardiovascular anomalies
multiple acyl-CoA dehydrogenase deficiency
Jeune syndrome
Marden-Walker syndrome
...
Article
Paracondylar process
The paracondylar process, also known as the paraoccipital, paramastoid, parajugular or estiloid process, is a rare anatomical variant of the occipital bone where a bony exostosis extends caudally from the paracondylar region (lateral to the native occipital condyles), typically articulating with...