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 edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

19 results found
Article

Waldenström sign

Waldenström sign is the increased distance between the pelvic tear drop and the femoral head. It is a non-specific sign of hip joint effusion. Radiographic features Radiograph >11 mm total distance or >2 mm difference compared to contralateral hip 1, 2 measured between the lateral aspe...
Article

Walking man sign

The walking man sign is seen on lateral chest radiograph and is a sign of left atrial enlargement. It results from posterior displacement of the left main bronchus such that it no longer overlaps the right bronchus. The left and right bronchus thus appear as an inverted 'V', mimicking the legs o...
Article

Wasp-waist sign

The wasp-waist sign is a radiographic appearance seen in patients with Klippel Feil syndrome. It results from fusion of the vertebral bodies such that the anteroposterior diameter at the level of the affected discovertebral joint is smaller than the diameter at the superior and inferior limits o...
Article

Water bottle sign

The water bottle sign or configuration refers to the shape of the cardiac silhouette on erect frontal chest x-rays in patients who have a very large pericardial effusion. Typically the effusion has accumulated over many weeks to months (e.g. in patients with malignancy) and the pericardium has g...
Article

Water-lily sign

The water-lily sign is seen in hydatid infections when there is detachment of the endocyst membrane which results in floating membranes within the pericyst that mimic the appearance of a water lily. It is classically described on plain radiographs (mainly chest X-ray) when the collapsed membran...
Article

Wave sign

The wave sign refers to the indentation of the normal thymus in young children by the ribs, resulting in a wavy border.
Article

Weapon and munition inspired signs

Weapons and munition inspired signs include the following with their corresponding pathologic conditions: bayonet deformity Turner syndrome chondrodysplasia bullet-shaped vertebra ​mucopolysaccharidosis achondroplasia cannonball metastases ​metastases from renal cell carcinoma dagger si...
Article

Westermark sign

Westermark sign is a sign of pulmonary embolus (PE) seen on chest radiographs. Along with Fleishner sign and Hampton hump, it makes one of the one of the three described signs of pulmonary embolus on chest radiographs. Pathology In one study (PIOPED) this sign was present on ~10% of chest x-r...
Article

Wheels within wheels sign

This sign is seen in USG of patient with the hepatic candidiasis and described as central hypoechoic area (necrosis containing fungi) surrounded by an echogenic zone (inflammatory cells). Differs from bull’s-eye sign for reverse echogeniticity, as it consists a central echogenic nidus surrounde...
Article

Whirlpool sign

The whirlpool sign, also known as the whirl sign, is seen when structures twist on itself. It is most commonly described in the abdomen bowel rotates around its mesentery, with mesenteric vessels creating the whirls but is also seen in ovarian torsion. Whirlpool sign: mesenteric It is seen in ...
Article

White cerebellum sign

White cerebellum sign, also called reversal sign or dense cerebellum sign, is encountered when there is a diffuse decrease in density of the supratentorial brain parenchyma, with relatively increased attenuation of the thalami, brainstem and cerebellum. This sign indicates irreversible brain dam...
Article

White matter buckling sign

The white matter buckling sign is helpful in distinguishing an extra-axial mass from an intra-axial one, and represents the white matter projecting into gyri being compressed and displaced by the mass, even in the presence of oedema (which would usually expand gyri, if the mass were intra-axial)...
Article

White pyramid sign

Medullary pyramids of kidney can be seen normally on unenhanced CT scans as high-attenuation structures and this is known as the white pyramid sign: bilateral high-attenuation renal pyramids are an occasional incidental normal finding unilateral appearance of white pyramids is subtle secondary...
Article

Widened intercondylar notch

A widened intercondylar notch on knee radiographs is a sign associated with: haemophilic arthropathy juvenile rheumatoid arthritis
Article

Wimberger ring sign

Wimberger ring sign refers to a circular calcification surrounding the osteoporotic epiphyseal center of ossification in scurvy, which may result from bleeding. It must not be confused with Wimberger sign, pathognomonic of congenital syphilis.
Article

Wimberger sign

The Wimberger sign, also called Wimberger corner sign, refers to localised bilateral metaphyseal destruction of the medial proximal tibias. It is a pathognomonic sign for congenital syphilis. It must not be confused with Wimberger ring sign seen in scurvy, which is sometimes also referred to as...
Article

Windsock sign (aortic dissection)

The windsock sign refers to appearances seen in type A thoracic aortic dissections on contrast CT. It results from intimo-intimal intussussception between the true and false dissected lumens of the thoracic aorta. The altering density of contrast between the dissection lumens which taper distall...
Article

Windsock sign (duodenal web)

The windsock sign is a typical appearance of a duodenal web (intraluminal duodenal diverticulum) on upper gastrointestinal contrast series which consists of an intraduodenal barium-contrast filled sac that is surrounded by a narrow lucent line (web or intraluminal mucosal diaphragm) which is wel...
Article

Winking owl sign

The (absent) pedicle sign, also called the winking owl sign, occurs on plain film when a pedicle is absent. The term, winking owl sign, where the missing pedicle corresponds to the closed eye, the contralateral pedicle to the other open eye, and the spinous process to the beak of the animal on ...

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