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
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
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
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
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
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...
Article
Polydactyly
Polydactyly (less commonly called hyperdactyly) refers to the situation where there are more than the usual number of digits (five) in a hand or foot. It can be broadly classified as:
preaxial polydactyly: extra digit(s) towards the thumb/hallux (radially)
postaxial polydactyly: extra digit(s)...
Article
Susac syndrome
Susac syndrome, also known as retinocochleocerebral vasculopathy or SICRET syndrome (small infarctions of cochlear, retinal and encephalic tissue), is a rare syndrome typically affecting young to middle-aged women that is clinically characterized by the triad of acute or subacute encephalopathy,...
Article
Colonic lipoma
Colonic lipomas are benign nonepithelial adipocytic tumors and a location-specific subtype of gastrointestinal lipomas.
Epidemiology
Colonic lipomas are rare, with an estimated frequency between 0.2 and 4.4%. They are seen more frequently in women aged between 40 and 70 years 1,2.
Clinical Pr...
Article
Traumatic spinal cord injury
Traumatic spinal cord injury can manifest as a wide variety of clinical syndromes resulting from damage to the spinal cord or its surrounding structures. It can result from minor injury if the spine is weakened from disease such as ankylosing spondylitis or if there is pre-existing spinal stenos...
Article
Myocardial edema
Myocardial edema refers to an increased water content of the myocardium particularly within the extracellular interstitium 1.
Clinical presentation
Myocardial edema often reflects an acute or subacute cardiac event, most often either ischemic or inflammatory and thus can be associated with che...
Article
Myocardial injury
Myocardial injury is defined by an elevation of cardiac troponin values above the 99th percentile upper reference limit. It is considered a prerequisite for the diagnosis of myocardial infarction but also an entity in itself and can arise from non-ischemic or non-cardiac conditions 1,2.
Termino...