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.

16,861 results found
Article

Temporal encephalocele

Temporal encephaloceles are usually small encephaloceles, often asymptomatic, but increasingly recognized as potential causes of refractory epilepsy and as a sequela of idiopathic intracranial hypertension. Epidemiology Temporal encephaloceles can be congenital or secondary to trauma, idiopath...
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Encephalocele

Encephalocele, also known as meningoencephalocele, is a form of neural tube defect and a type of cephalocele where brain tissue and overlying meninges herniate out through a defect in the cranium.  Terminology Although the terms encephalocele and meningoencephalocele are often used interchange...
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Sphenoidal encephalocele

Sphenoidal encephaloceles represent meningoencephaloceles which extend into or through the sphenoid bone. Terminology Sphenoidal meningoencephalocele can be divided in a number of ways: content: meningoceles vs encephaloceles location: medial vs lateral (see below) extent: instrasphenoidal ...
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Osteochondral defect

Osteochondral defects (OCD) or lesions (OCL) are focal areas of articular cartilage damage and injury of the adjacent subchondral bone plate and subchondral cancellous bone.  Terminology Osteochondral defect is a broad term that describes the morphological changes associated to a localized gap...
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Percutaneous endoscopic gastrostomy

Percutaneous endoscopic gastrostomy (PEG) is a procedure where a flexible feeding tube (commonly known as a PEG tube) is inserted through the abdominal wall and into the stomach via endoscopy. Alternatively a tube can be placed under radiological guidance, known as a radiologically inserted gast...
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Penetrating thoracic trauma

Penetrating thoracic trauma, namely gunshot and stab injuries, vary widely in incidence globally but nevertheless result in high mortality and serious morbidity. CT is the modality of choice in imaging these patients and can reduce the need for surgical exploration.  Pathology Penetrating thor...
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Germinal matrix hemorrhage (grading mnemonic)

A mnemonic to remember the radiological grading of germinal matrix hemorrhage is: CV2P  Mnemonic It can be read as a central venous line C: limited to the caudothalamic groove/ germinal matrix ( grade I ) V: expansion into ventricles less than 50% ( grade II ) V: dilated ventricles ( grade...
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Penetrating abdominopelvic trauma

Penetrating abdominopelvic trauma usually occurs in the setting of gunshot and stab injuries and is associated with high morbidity and mortality. CT is the modality of choice in imaging if the patient is stable enough before surgery. The most common injuries include small bowel, large bowel, liv...
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Using and attributing images from Radiopaedia

Using images from Radiopaedia in your presentations is not only OK but is actively encouraged. Radiopaedia is all about sharing our knowledge and cases and by so doing, makes it easier to teach and to learn from each other.  To download an image, just click the download icon (little cloud with ...
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Germinal matrix hemorrhage (grading)

Grading of germinal matrix hemorrhage has taken several forms over the years. The most commonly used system is the sonographic grading system proposed by Burstein, Papile, et al.  Classification grade I restricted to subependymal region/germinal matrix which is seen in the caudothalamic groov...
Article

Cerebral small vessel disease

Cerebral small vessel disease, also known as cerebral microangiopathy, is an umbrella term for lesions in the brain attributed to pathology of small arteries, arterioles, capillaries, venules, or small veins. It is the most common cause of vascular dementia/cognitive impairment and is a major ca...
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Playlists

Playlists are a fantastic way of collecting, organizing and sharing cases. They are an ordered collection of cases that you can then play from start to finish. We have gathered some examples of educational playlists for you to browse.  Playlists can also have intervening static slides. The res...
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Dose length product

Dose length product (DLP) is a measure of CT tube radiation output/exposure (measured in mGy.cm). It is related to volume CT dose index (CTDIvol), but CTDIvol represents the dose through a slice of an appropriate phantom. The dose length product accounts for the length of radiation output along ...
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Postaxial polydactyly

Postaxial polydactyly refers to polydactyly where the additional digit is on the ulnar margin of the hand, or lateral to the 5th (little) toe. Epidemiology Postaxial polydactyly is more common than preaxial polydactyly, with an estimated incidence of 1 in 3000 5. Associations trisomy 13 Bar...
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Brain death

Brain death (or death by neurological criteria) refers to the irreversible end of all brain activity and is usually assessed clinically. Radiographic testing may be used as additional support for a clinical diagnosis of brain death, such as when clinical tests are impossible to perform, e.g. fac...
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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)...
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Empty light bulb sign (brain death)

In brain death, on Tc-99m HMPAO imaging there is absent or reduced flow in the internal carotid arteries and increased flow within the external carotid arteries. This leads to absent uptake in the brain with subsequent increased perfusion in the nasal region. This appearance has been called the ...
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Hot nose sign

The hot nose sign refers to increased perfusion in the nasal region on nuclear medicine cerebral perfusion studies in the setting of brain death. The absent or reduced flow in the internal carotid arteries is thought to lead to increased flow within the external carotid arteries and subsequent i...
Article

Intrapelvic cup migration

Intrapelvic cup migration is a serious complication after total hip arthroplasty, in which the prosthetic acetabular cup migrates or drifts into the pelvic inlet. Epidemiology Fortunately, this complication is very rare. There seems to be a female predisposition 1-3. Risk factors Factors inc...
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Fecal impaction

Fecal impaction is the inability to spontaneously evacuate solid feces. It is common in the elderly population. A severe form of fecal impaction is often referred to as a fecaloma.  Terminology Fecal loading is a poorly defined term but generally refers to the volume of fecal material in the c...

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