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.
86 results found
Article
Flame sign (carotid)
The flame sign refers to a gradual tapering of contrast opacification in the mid-cervical internal carotid artery, sparing the carotid bulb. The sign can be observed on angiography (digital subtraction angiography 1, CT angiography 1, or contrast-enhanced MR angiography 2) in either of two scena...
Article
Mickey Mouse sign (disambiguation)
In medical imaging, a Mickey Mouse sign or appearance has been given to imaging features that mimic Mickey Mouse when viewed from the front. It has been described in the following:
anencephaly 2
progressive supranuclear palsy 1
synonymously with a finger in glove sign
the flared shape of the...
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...
Article
Inferior vena caval contrast reflux
Reflux of contrast into inferior vena cava can be common findings seen on CT. It is considered a specific but insensitive sign of right-sided heart disease / right heart dysfunction at low contrast injection rates although the usefulness decreases with high injection rates.
Conditions associate...
Article
Kissing carotids
The term kissing carotids refers to tortuous and elongated carotid arteries which touch in the midline. They can be found in:
retropharynx 2
intrasphenoid 1
within the pituitary fossa
within sphenoid sinuses
within sphenoid bones
The significance of kissing ca...
Article
Pretzel sign (serpentine aneurysm)
The pretzel sign is seen on DSA and is indicative of a serpentine aneurysm 1.
The sign refers to the sinusoid configuration of the intra-aneurysmal vascular channel seen in serpentine aneurysms, giving it the appearance of a pretzel.
Article
Egyptian eye sign
"Egyptian eye sign" or "sonographic eye sign" refers to the normal appearance of great saphenous vein on ultrasound, in transverse view 1,2.
Ultrasound examination of the great saphenous vein shows echogenic fascia surrounding it, with the saphenous fascia superiorly and the muscular fascia inf...
Article
Yin-yang sign (vascular)
The yin-yang sign, also known as the Pepsi sign, is a radiological sign described in both true and false aneurysms on various imaging modalities.
Radiographic features
Ultrasound
On Doppler ultrasound, the yin-yang sign indicates bidirectional flow due to the swirling of blood within the true...
Article
Teardrop sign (superior mesenteric vein)
The teardrop sign of the superior mesenteric vein is one of the important signs in the local staging of pancreatic adenocarcinoma. Its importance lies in its diagnostic, as well as prognostic, significance. This sign is used in assessing the resectability of pancreatic cancer.
Radiographic feat...
Article
Flashlight sign (B-flow)
The flashlight sign is a B-flow vascular ultrasound sign caused by wall adherent and floating thrombi and emboli in arteries, which appear as bright spots on imaging.
Radiographic features
Ultrasound
The flashlight sign is described as a moving, very bright intraluminal focus of signal on B-f...
Article
Crescent sign of arterial dissection
The crescent sign refers to the high signal crescent seen in the wall of a vessel when dissected. This may be seen both on T1 or T2 sequences depending on the age of the blood (see aging blood on MRI). It is classically referred to in internal carotid artery dissection.
It should not be confuse...
Article
Tulip bulb sign
The tulip bulb sign refers to the characteristic appearance of annuloaortic ectasia as seen on CT angiography.
There is symmetric dilatation of the three sinuses of Valsalva, with extension into the ascending aorta and effacement of the sinotubular junction.
It is seen especially in Marfan sy...
Article
Double density sign (berry aneurysm)
Double density sign of berry aneurysms refers to the angiographic appearance of a small intracranial aneurysm projecting in front or behind a vessel of similar caliber. As such, the border of the aneurysm cannot easily be seen, but the extra contrast within it can be seen as a rounded area of in...
Article
Unfolded aorta
The term unfolded aorta refers to the widened and decreased curvature of the aortic arch on a frontal chest radiograph giving an ‘opened up’ appearance. It is one of the more common causes of apparent mediastinal widening and is seen with increasing age, usually associated with aortic calcificat...
Article
Floating viscera sign
The floating viscera sign is an angiographic sign that occurs when there is visualization of branches of the abdominal aorta (e.g. celiac axis, superior mesenteric artery, and renal arteries) during aortography with little or no visualization of the aortic lumen.
The floating viscera sign indic...
Article
Pseudovein sign (bowel)
The pseudovein sign can occur with active gastrointestinal bleeding where contrast extravasation during angiography may have a curvilinear appearance as it pools in the gastric rugae or mucosal folds of bowel, mimicking the appearance of a vein. However, contrast in the “pseudovein” persists bey...
Article
String sign (disambiguation)
The string sign may refer to:
angiographic string sign
gastrointestinal string sign
string sign of parosteal osteosarcoma
myositis ossificans string sign
Article
Temporal tap maneuver
Temporal tap maneuver consists in tapping over the ipsilateral superficial temporal artery while assessing the carotid bifurcation on Doppler ultrasound aiming to produce a reflected flow in the external carotid artery (ECA) and thus helping to distinguish which vessel is being assessed: externa...
Article
Cobweb sign of arterial dissection
The cobweb sign is seen in cases of arterial dissection (usually aortic dissection) on CT angiogram (CTA) examinations and represents strands or ribbons of media crossing the false lumen, and appearing as thin filiform filling defects.
Although it is a specific sign for the false lumen, it is i...
Article
Capps triad
Capps triad refers to the constellation of clinical and imaging findings in patients with a spontaneous retropharyngeal hematoma, and consists of:
tracheal and esophageal compression
anterior displacement of the trachea
subcutaneous bruising over the neck and anterior chest
History and etymo...
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