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.
16,854 results found
Article
Mitral annular calcification
Mitral annular calcification refers to the deposition of calcium (along with lipid) in the annular fibrosa of the mitral valve.
Epidemiology
Annular calcification is seen in up to 35% of elderly patients. It is common in females over 65 years, in those with myxomatous degeneration of the mitra...
Article
Intraosseous lipoma
Intraosseous lipomas are rare benign lesions that account for about 0.1-2.5% of all bone tumors. They are, however, the most common lipogenic tumors in bone 6.
Intraosseous lipomas account for one of the 'I's in the popular mnemonic for lucent bone lesions FEGNOMASHIC.
Epidemiology
Intraosseo...
Article
Lucent/lytic bone lesion - differential diagnosis (mnemonic)
Mnemonics for the differential diagnosis of lucent/lytic bone lesions include:
FEGNOMASHIC
FOG MACHINES
They are anagrams of each other and therefore include the same components. They are by no means exhaustive lists, but are a good start for remembering a differential for a lucent/lytic bone...
Article
Langerhans cell histiocytosis (skeletal manifestations)
The skeleton is the most commonly involved organ system in Langerhans cell histiocytosis (LCH) and is by far the most common location for single-lesion LCH, often referred to as eosinophilic granuloma (EG) (the terms are used interchangeably in this article). For a general discussion of this dis...
Article
Dengue fever
Dengue fever is a mosquito-borne acute systemic viral infection caused by any of the four serotypes of the dengue virus.
Epidemiology
Dengue virus infections occur predominately in tropical and subtropical regions 3.
Clinical presentation
The infection can lead to a broad spectrum of sympto...
Article
Unlisted cases
Unlisted cases are great if you don't want other users to see them but still want to be able to easily share them with others.
When you have created a case you can set its visibility to unlisted.
Unlisted cases are:
not...
visible to other users when browsing Radiopaedia.org
indexed by se...
Article
Steelpan sign (sigmoid volvulus)
The steelpan sign refers to the close resemblance of sigmoid volvulus on CT to the percussion instrument known as the steelpan. The steelpan, also known as steel drum or pan, is a Caribbean musical instrument invented in Trinidad and Tobago by the mid-1930s, which became very popular in Trinidad...
Article
CT myelography
CT myelography (CTM) is a myelography technique used mainly to assess for potential spinal canal stenosis when MRI is contraindicated or when dynamic imaging is required.
History
CT myelography was first performed in 1976 2 and became the gold standard for imaging the spinal canal and cord unt...
Article
Spatial resolution (CT)
Spatial resolution in CT is the ability to distinguish between objects or structures that differ in density.
A high spatial resolution is important for one to discriminate between structures that are located within a small proximity to each other.
Factors affecting CT spatial resolution
fiel...
Article
Sharing cases and playlists
Sharing cases and playlists is a cornerstone of what Radiopaedia is all about. As such we offer a number of ways for cases and playlists to be shared and these can be accessed via the "share" button. Each of the ways of sharing has its own URL and all you need to do is copy one and share online,...
Article
Paralabral cyst of the hip
Paralabral cysts of the hip joint are a location-specific subtype of paralabral cysts. They are predominantly small, sometimes septate, well-defined multiloculated fluid intensity lesions. They are closely associated with acetabular labral tears. Their presence requires a thorough search for a l...
Article
LI-RADS
Liver Imaging Reporting and Data System (LI-RADS) is a set of standardized terminology and classification systems for imaging findings in liver lesions. The LI-RADS score for a liver lesion is an indication of its relative risk for hepatocellular carcinoma (HCC).
The classification system is me...
Article
Talus
The talus (plural: tali 4), historically known as the astragalus, is a tarsal bone in the hindfoot that articulates with the tibia, fibula, calcaneus, and navicular bones. It has no muscular attachments and around 60% of its surface is covered by articular cartilage.
Gross anatomy
The talus h...
Article
Short tau inversion recovery
Short tau inversion recovery (STIR), also known as short TI inversion recovery, is a fat suppression technique with an inversion time TI = ln(2)·T1fat, where the signal of fat is zero. This equates to approximately 140 ms at 1.5 T.
To distinguish two tissue components with this technique, their...
Article
Kayser-Fleischer rings
Kayser-Fleischer rings, sometimes shortened to K-F rings, are caused by copper deposition in the cornea and are a specific, clinical sign of Wilson disease.
Clinical presentation
They are usually brown or dark reddish in color. Early on they may need a slit lamp to be visible before they becom...
Article
Morquio syndrome
Morquio syndrome (in older literature it is sometimes called Morquio-Brailsford syndrome) is an autosomal recessive mucopolysaccharidosis (MPS) type IV.
Epidemiology
Incidence estimated at ~1:40,000.
Clinical presentation
Many cases present at ~2 years of age and have normal intelligence. Cl...
Article
Aortic valve
The aortic valve (AV) is one of the four cardiac valves. It is the semilunar valve that allows blood to exit the left ventricle (LV). It opens during systole and closes during diastole.
The valve has left, right, and posterior cusps, the bases of which attach around the valve orifice to a fibro...
Article
Babygram
Babygram is a radiograph that captures the newborn's entire body, including limbs. Alternatively, it may only capture the chest and abdomen.
Indications
Babygram is done in AP and lateral views in post-mortem studies of the stillborn foetus or after the termination of pregnancy due to gross co...
Article
Spinal cord stimulator
Spinal cord stimulators, also known as dorsal column stimulators, are surgically placed devices intended to provide symptom relief in individuals with chronic neurological pain (e.g. failed back syndrome, brachial plexopathy, complex regional pain syndrome).
However, their use remains controver...
Article
Hysterosalpingogram
A hysterosalpingogram (HSG) is a fluoroscopic examination of the uterus and the fallopian tubes, most commonly used in the investigation of infertility or recurrent spontaneous abortions.
Indications
infertility: to assess uterine morphology and tubal patency
Contraindications
pregnancy
act...