Articles
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More than 200 results
Article
Extrapleural fat sign
The extrapleural fat sign is an imaging feature which can be seen on CT under certain circumstances. It occurs from the inward displacement of extrapleural fat by an extrapleural fluid collection, extrapleural hematoma or extrapleural mass. The presence of the extrapleural fat sign is indicative...
Article
Pooping duck sign
Pooping duck sign indicates the presence of a triquetral fracture on a lateral wrist radiograph, where an avulsed fracture fragment from the dorsal cortex of the triquetrum projects along the dorsal aspect of the osseous structures of the wrist.
In this sign, the fracture fragment represents th...
Article
Bird beak sign (esophagus)
The bird's beak sign of the esophagus is used to refer to the tapering of the inferior esophagus in achalasia. The same appearance is also referred to as the rat's tail sign.
The appearance, although classically occurring in primary achalasia, can also occur in pseudoachalasia due to a gastric ...
Article
H-shaped vertebra
H-shaped vertebrae, also known as Lincoln log vertebrae, are a characteristic finding of sharply delimited central endplate depression, classically seen in approximately 10% of patients with sickle cell disease, and results from microvascular endplate infarction (Figure 1) 3.
It may occasionall...
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Thumb sign (chordoma)
The thumb sign or thumbing of the pons is described in chordomas as is meant to be relatively specific. It is seen in midline sagittal projection as a projection of the tumor indenting the pons 1,2.
See also
thumb sign (disambiguation)
Article
Small heart sign
The small heart sign represents a rarely encountered but critical sign on chest caused by a sudden reduction of heart size caused by cardiac tamponade due to either tension pneumopericardium or pneumomediastinum.
A sudden, >2 cm reduction in the transverse cardiac diameter is considered highly...
Article
Centrilobular micronodules
Centrilobular micronodules are an image descriptor that refers to centrilobular nodules when the nodules are very small and present in a centrilobular distribution in the lungs. They are usually seen with bronchiolitis and can blend into tree-in-bud opacities.
Radiographic features
CT
Postpr...
Article
Bilateral middle cerebellar peduncle lesions
Bilateral lesions of the middle cerebellar peduncles, resulting in the middle cerebellar peduncle sign, are uncommon and can be seen either in isolation (rare) or along with other regions of involvement.
Despite their relative rarity, they have a fairly long list of potential causes (see below)...
Article
Upper lobe pulmonary venous diversion
Upper lobe pulmonary venous diversion (also described as cephalisation of the pulmonary veins) reflects elevation of left atrial pressure and is an early sign of pulmonary edema.
Clinical presentation
The normal left atrial pressure is 5-10 mmHg. An elevation of left atrial pressure to 10-15 m...
Article
Torricelli-Bernoulli sign
The Torricelli-Bernoulli sign denotes non-dependent air trapped in a necrotic ulcer in a gastrointestinal tumor seen on axial CT or MRI. Occasionally, a vertical stream of bubbles can be seen issuing from the orifice of the ulcer.
Terminology
Torricelli's theorem gives the relation of the velo...
Article
Cockade sign (intraosseous lipoma)
The cockade sign describes the classic appearance of a calcaneal intraosseous lipoma seen as a well-defined lytic lesion with a central calcification.
History and etymology
It is named after a cockade, which is a badge, usually in the form of a rosette or knot, generally worn on the hat.
Article
Sea anemone sign
The sea anemone sign is a unique (but not wholly exclusive) appearance seen in ovarian serous surface papillary borderline tumors (SSPBT). It refers to its surface stroma frequently branches into exophytic papillary stalks, macroscopically 1.
Radiographic features
On cross-sectional imaging, p...
Article
Baastrup disease
Baastrup disease or syndrome (also referred to as kissing spines) is a cause of low back pain characterized by interspinous bursitis and other degenerative changes of the bones and soft tissues where adjacent spinous processes in the lumbar spine rub against each other.
Epidemiology
It tends t...
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Mackler's triad
Mackler's triad consists of the clinical symptoms of vomiting, followed by severe pain in the chest, usually retrosternal, lower thoracic, and upper abdominal, associated with subcutaneous emphysema detected on physical examination, which is suggestive of esophageal rupture (Boerhaave syndrome) ...
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Anderson triad
The Anderson triad consists of the clinical findings of tachypnea and abdominal rigidity with lower thoracic or epigastric pain, associated with subcutaneous emphysema, which is usually related to esophageal rupture.
Article
Cingulate sulcus sign
The cingulate sulcus sign has been proposed as being useful as an MRI feature of idiopathic normal pressure hydrocephalus (NPH). It denotes the posterior part of the cingulate sulcus being narrower than the anterior part. The divider between the anterior and posterior parts of the sulcus being a...
Article
Dural tail sign
The dural tail sign occurs as a result of thickening and enhancement of the dura and is most often seen adjacent to a meningioma.
Initially, the sign was felt to be pathognomonic of meningiomas, however, it has become increasingly noted to be present in many other conditions, although without t...
Article
Tam o' Shanter sign (skull)
This imaging sign is named after the Tam o' Shanter, a Scottish hat, named after the character in Robert Burns's 1 poem of the same name. The appearances of advanced Paget disease of the skull are similar in appearance to the hat.
Paget involvement of the skull, with widening of the diploic sp...
Article
Target sign (choledocholithiasis)
The target sign of choledocholithiasis is a finding seen on contrast-enhanced CT and comprises:
central density within the bile duct: stone
surrounding low density: bile or mucosa
Article
Contrast level within inferior vena cava
A dependent contrast level within the inferior vena cava is a situation that can be observed in some cases with inferior vena caval contrast reflux. Its presence is usually associated with very poor cardiac output and can be accompanied by dependent layering of venous refluxed contrast within th...
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