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
Tracheomalacia (differential)
A dilated trachea has numerous causes, and in almost all cases represents tracheomalacia (increased size and increased compliance).
As is almost always the case, various diameters have been used. Typical figures include >26 mm in men, >23 mm in women or >30 mm for both genders ref.
Although ma...
Article
Post-primary pulmonary tuberculosis
Post-primary tuberculosis is also known as reactivation tuberculosis or secondary tuberculosis. The typical upper zone predominant destructive pneumonia is due to an adaptive immune response in an immunocompetent host 1.
Pathology
Location
The upper zone predominance of pulmonary cavitation c...
Article
Valveless vein
The valveless veins are veins that lack venous valves. Most veins contain valves (known as the valvula venosa in the TA) to prevent backflow, i.e. ensuring that blood flow is always towards the heart 1.
It has been shown that veins that were previously thought to be valveless actually do have v...
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
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
Interstitial lung abnormality
Interstitial lung abnormality (ILA) refers to incidental bilateral non-dependent CT patterns including reticulation, traction bronchiectasis and honeycombing that may be symptomatic, may progress to fibrosis and portend a higher all cause mortality risk 7.
Epidemiology
Although may vary from p...
Article
Benign enhancing foramen magnum lesion
Benign enhancing foramen magnum lesions, also described as high signal lesions, are an incidental finding on 3D FLAIR MRI in a typical location in the foramen magnum just posterior to the intradural vertebral artery.
Epidemiology
The prevalence of this finding was 3% in a retrospective review...
Article
Myocardial infarction
Myocardial infarction (MI), colloquially known as a heart attack, an acute coronary syndrome, results from interruption of myocardial blood flow and resultant ischemia and is a leading cause of death worldwide.
Epidemiology
Risk factors
male > females
age
>45 years for males
>55 years for...
Article
MR tagging
Cardiac MR tagging or myocardial tagging refers to an MRI-based acquisition method designed for the analysis of myocardial deformation.
Technique
The method exploits tissue magnetization as a tissue property. A local magnetic saturation grid of dark-lined tissue markers known as tags are induc...
Article
Tension pneumocephalus
Tension pneumocephalus is a neurosurgical emergency that occurs when subdural air causes a mass effect over the underlying brain parenchyma, often from a ball-valve mechanism causing one-way entry of air into the subdural space 1.
Clinical presentation
Tension pneumocephalus has a varied clini...
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
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
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...