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
Snowstorm sign (extracapsular breast implant rupture)
The snowstorm sign on breast ultrasound imaging represents the presence of free silicone droplets mixed with breast parenchymal tissue causing characteristic homogeneously hyperechoic dense shadowing with dispersion of the ultrasound beam. It is considered the most reliable sign of extracapsular...
Article
Intracerebral hemorrhage
An intracerebral hemorrhage, or intraparenchymal cerebral hemorrhage, is a subset of an intracranial hemorrhage as well as of stroke, defined by the acute accumulation of blood within the brain parenchyma.
This article concerns non-traumatic intracerebral hemorrhages; traumatic hemorrhagic cere...
Article
Lipomatous hypertrophy of the interatrial septum
Lipomatous hypertrophy of the interatrial septum is a relatively uncommon disorder of the heart characterized by benign fatty infiltration of the interatrial septum. It is commonly found in elderly and obese patients as an asymptomatic incidentally discovered finding.
Epidemiology
The prevale...
Article
Subacromial impingement
Subacromial impingement is the most common form of shoulder impingement and occurs secondary to attrition between the coracoacromial arch and the underlying supraspinatus tendon or subacromial bursa, leading to tendinopathy and bursitis respectively.
Pathology
Etiology
acromial shape
os acro...
Article
Brachial plexus injuries
Brachial plexus injuries are a spectrum of upper limb neurological deficits secondary to partial or complete injury to the brachial plexus, which provides the nerve supply of upper limb muscles.
Clinical presentation
Trauma, usually by motor vehicle accidents, involves severe traction on the ...
Article
Vasa vasorum
The vasa vasorum represents the supporting microvasculature of the larger caliber arteries and veins of the body.
Gross anatomy
The vasa vasorum has two subtypes in humans 2,3:
arterial vasa vasorum: arises from various arteries based on anatomical location (e.g. intercostal arteries for desc...
Article
Cardiac CT
Computed tomography of the heart or cardiac CT is routinely performed to gain knowledge about cardiac or coronary anatomy, to detect or diagnose coronary artery disease (CAD), to evaluate patency of coronary artery bypass grafts or implanted coronary stents or to evaluate volumetry and cardiac f...
Article
Greater tubercle fracture of the shoulder
Greater tubercle/tuberosity fractures of the shoulder are a subtype of proximal humeral fractures.
Gross anatomy
The greater tubercle is the most lateral bony part of the shoulder. It is the site where three of the rotator cuffs insert to abduct or laterally rotate the shoulder joint (supraspi...
Article
Tangent sign of supraspinatus muscle belly atrophy
The tangent sign is useful in helping to quantify supraspinatus muscle belly atrophy with a positive sign implicated with a poorer outcome after supraspinatus tendon tear repair.
Measurement
On a sagittal oblique plane, a line is drawn between the upper surface of the scapular spine and the up...
Article
Digital breast tomosynthesis
Digital breast tomosynthesis (DBT) is an imaging technique that allows a volumetric reconstruction of the whole breast from a finite number of low-dose two-dimensional projections obtained by different X-ray tube angles, with a geometric principle very similar to that applied in stratigraphic te...
Article
Koos grading scale
The Koos grading scale 1 is frequently used as a classification system for vestibular schwannomas.
Classification
grade 1: small intracanalicular tumor
grade 2: small tumor with protrusion into the cerebellopontine cistern (CPA); no contact with the brainstem
grade 3: tumor occupying the cer...
Article
Carotidynia
Carotidynia, also known as Fay syndrome, is a rare syndrome characterized by neck pain in the region of the carotid bifurcation.
It was classified by the International Headache Society (IHS) in 1988 as an idiopathic neck pain syndrome associated with tenderness over the carotid bifurcation with...
Article
Systemic hypertension
Systemic hypertension is defined medically as a blood pressure greater than 140/90 mmHg. The American College of Cardiology (ACC) and American Heart Association (AHA) have changed guidelines to indicate that pressures above 130/80 mmHg will be considered hypertension, however, the European Socie...
Article
Diffusion tensor imaging and fiber tractography
Diffusion tensor imaging (DTI) is an MRI technique that uses anisotropic diffusion to estimate the axonal (white matter) organization of the brain.
Fiber tractography (FT) is a 3D reconstruction technique to assess neural tracts using data collected by diffusion tensor imaging.
Diffusion-weigh...
Article
Pulmonary artery catheter
Pulmonary artery catheters (PAC or Swan-Ganz catheters) are balloon flotation catheters that are inserted into the pulmonary arteries. They can be inserted simply, quickly, with little training and without fluoroscopic guidance at the bedside, even in the seriously ill patient.
Usage
Historica...
Article
All-trans-retinoic acid syndrome
All-trans-retinoic acid (ATRA) syndrome, is the more common cause of differentiation syndrome 8. Acute promyelocytic leukemia (APL) cells respond to therapeutic levels of this normal plasma derivative of vitamin A by maturating into normal granulocytes which can cause capillary leakage and organ...
Article
Spinning top urethra
Spinning top urethra is non-obstructive posterior urethral dilatation seen on voiding cystourethrography, mainly in females. It was initially considered as an indicator of distal urethral narrowing/stenosis. However, it is now believed to be due to functional discoordinate voiding or bladder ins...
Article
Rectoanal intussusception
Rectoanal intussusception refers to the telescoping or infolding of the rectal wall within the rectum itself, or into the anal canal, or externally, during defecation.
Terminology
Rectoanal intussusception is also termed internal intussusception and internal procidentia1 .
Epidemiology
Recto...
Article
Intraductal papillary mucinous neoplasm
Intraductal papillary mucinous neoplasms or tumors (IPMNs or IMPTs) are epithelial pancreatic cystic tumors of mucin-producing cells that arise from the pancreatic ducts. They are most commonly seen in elderly patients.
On imaging, particularly MRCP, they are characterized by single or multipl...
Article
Transsphenoidal hypophysectomy
Transsphenoidal hypophysectomy is a commonly used surgical approach for pituitary region masses, with many significant advantages over open craniotomy.
History
The transsphenoidal approach was first described in 1907 by Schloffer, modified by Halstead and subsequently popularized by Harvey Cu...