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.

39 results found
Article

Ballet sign

The Ballet sign refers paralysis of voluntary movements of the eyeball with preservation of the automatic movements. Sometimes this sign is present with exophthalmic goitre and hysteria.
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Black turbinate sign

The black turbinate sign refers to an area of non-enhancing mucosa on MRI in a patient with angioinvasive fungal sinus infection / rhinocerebral mucormycosis. Mucormycosis is caused by fungi that include Mucor, Rhizopus, and Absidia species.  It is seen in diabetic and immunocompromised patient...
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Capp triad

The Capp triad refers to the constellation of clinical and imaging findings in patients with spontaneous retropharyngeal haematomas, and consists of: tracheal and oesophageal compression anterior displacement of the trachea subcutaneous bruising over the neck and anterior chest
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Cloverleaf skull

A cloverleaf skull (also known as kleeblattschädel) refers to type of severe craniosynostosis which gives the skull a cloverleaf shape. It typically results from intrauterine premature closure of sagittal, coronal and lambdoid sutures. Pathology Associations thanatophoric dysplasia: classical...
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Coca-Cola bottle sign

The coca-cola bottle sign refers to the appearance of the muscles of the orbit in thyroid eye disease.  The belly of the muscle enlarges with sparing of the tendinous insertion, giving the appearance of the traditional coca-cola bottle. The enlargement of the muscles follows the I'M SLOW format...
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Convoluted cerebriform pattern

A convoluted cerebriform pattern is a term used to denote the appearance of an sinonasal inverted papilloma on MRI. The appearance is seen on both T2 and post contrast T1 images and appears as alternating roughly parallel lines of high and low signal intensity. This sign has been reported as p...
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Disc herniation

Disc herniation refers to displacement of intervertebral disc material beyond the normal confines of the disc, but involving less than 25% of the circumference (to distinguish it from a disc bulge. A herniation may contain nucleus pulposus, vertebral endplate cartilage, apophyseal bone/osteophyt...
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Double disc sign

Thickening of the insertion of the lateral pterygoid muscle can mimic an anterior displaced TMJ disc. When both thickening of the inferior belly insertion and an anteriorly displaced disc are present, the two structures parallel each other; the so called "double disc" sign.
Article

Fistula test

The fistula test is used when examining patient with recurrent vertigo. A finger is abruptly applied to the external meatus which causes a pulse of air-transmitted pressure. If nystagmus is induced in association with vertigo, it indicates bony destruction within the inner ear e...
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Geographic skull

A geographic skull is a radiographic appearance which is seen at eosinophilic granuloma (EG) and characterized by destructive lytic bone lesion, edges of which may be bevelled, scalloped or confluent.
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Griesinger sign

Griesinger sign, named after Wilhelm Griesinger, a German psychiatrist and neurologist (1817-1868) refers to oedema of the postauricular soft tissues overlying the mastoid process as a result of thrombosis of the mastoid emissary vein. It is a complication of acute otomastoiditis and may be asso...
Article

Guttman sign

Guttman sign is a clinical sign relating to the function of the larynx. In normal subjects, frontal pressure on the thyroid cartilage lowers the tone of voice produced and lateral pressure produces a higher tone of voice. The opposite is true with paralysis of the cricothyroid muscle.
Article

Hennebert sign

The Hennebert sign describes a positive fistula test without clinical evidence of middle ear or mastoid disease. It is associated with congenital syphilis and may also be present in Meniere disease. It has been postulated that the vestibular stimulation is mediated by fibrous bands between foo...
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Holman-Miller sign

The Holman-Miller sign (also called antral sign) is seen in juvenile nasopharyngeal angiofibroma. The anterior bowing of the posterior wall of the maxillary antrum which is seen on lateral skull film or cross-sectional imaging 1-2. This is a nonspecific sign that can be produced by any slowly g...
Article

Hutchinson sign

The Hutchinson sign can refer to two signs.  Hutchinson sign (ophthalmology) Relates to involvement of the tip of the nose from facial herpes zoster. It implies involvement of the nasal branch of the nasociliary nerve (branch of the ophthalmic division of the trigeminal nerve) and thus raises ...
Article

Hutchinson teeth

Hutchinson’s teeth are smaller and more widely spaced than normal and are notched on their biting surfaces. It is a sign of congenital syphilis and should not be confused with: Hutchinson's triad Hutchinson pupil Hutchinson freckle Hutchinson's sign Hutchinson syndrome History and etymolo...
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Hutchinson triad

Hutchinson triad of congenital syphilis consists of: dental abnormalities interstitial keratosis deafness History and etymology Named after Sir Johnathan Hutchinson, English surgeon, ophthalmologist and pathologist (1828 - 1913). Hutchinson's triad should not be confused with: Hutchinson ...
Article

Hyoid elevation

Hyoid elevation is an indication on a modified barium swallow study that the pharyngeal muscles are contracting appropriately. Radiographic findings Modified barium swallow With real time fluoroscopy (or videofluoroscopy) during the act of swallowing, the larynx moves upward and forward when ...
Article

Ice-cream cone sign

The ice cream cone sign may refer to: the appearance of the malleus head and the incus body on axial CT scan: failure of this normal configuration suggests incudomalleolar dysarticulation. Ball of the icecream is formed by head of malleus and cone is formed by body of incus. Space between ice c...
Article

Kissing carotids

The term kissing carotids refers to tortuous and elongated vessels which touch in the midline. They can be be found in:  retropharynx 2 intra-sphenoid 1 within the pituitary fossa within sphenoid sinuses within sphenoid bones The significance of kissing carotids is two-fold: may mimic int...
Article

Leontiasis ossea

Leontiasis ossea is largely a historical term used to describe a number of conditions that result in the affected patient's face resembling that of a lion. Although it is most frequently associated with craniofacial fibrous dysplasia, it has a broader meaning encompassing other lesions that have...
Article

Low attenuation lymphadenopathy

Low attenuation lymphadenopathy suggests underlying necrosis and can be seen in: metastatic carcinoma (or lymphoma) infections (tuberculous or fungal) Whipple disease coeliac sprue See also lymphadenopathy low attenuating lymphadenopathy high attenuating lymphadenoapthy
Article

Lyre sign

The lyre sign refers to the splaying of the internal and external carotid by a carotid body tumour. Classically described on angiography it is also visible on CT angiography.
Article

Meth mouth

Meth mouth is the name given to the overt dental disease that is one of the signs of methamphetamine use. Clinical presentation Clinical examination often reveals blackened, stained, rotting or crumbling teeth. Serial studies only a few years apart may show a striking deterioration in the pati...
Article

Omega sign

The omega sign refers to the thickened aryepiglottic folds and epiglottis seen in epiglottitis, when the larynx is seen endoscopically or via laryngoscope, and not to the appearance on lateral plain films. CT would show the finding, but placing a child with epiglottitis supine to CT their neck i...
Article

Orbital emphysema

Orbital emphysema is the presence of gas within the orbital soft tissues. It is usually due to orbital fractures communicating with the paranasal sinuses but can be caused by penetrating trauma and infection. It is a common finding also after orbital or ocular surgery.  Location preseptal pos...
Article

Perilymphatic fistula

A perilymphatic fistula (PLF) (also known as a labyrinthine fistula) is a pathologic communication between the fluid-filled space of the inner ear and the air-filled space of the middle ear, most commonly occurring at either the round or oval window. The primary manifestations of perilymphatic...
Article

Powers ratio

Powers ratio is a measurement of the relationship of the foramen magnum to the atlas, used in the diagnosis of atlanto-occipital dissociation injuries. The ratio, AB/CD, is measured as the ratio of the distance in the median (midsagittal) plane between the: basion (A) and the posterior spinola...
Article

Raccoon sign

Raccoon sign is periorbital ecchymosis and is indicative of skull base fracture of anterior cranial fossa.
Article

Raindrop skull

The appearance of multiple, well-defined lytic lesions (punched out lesions) of various size scattered throughout the skull constitutes the raindrop skull appearance of multiple myeloma. This term is applied as an analogy to rain hitting a surface and splashing, where it leaves a random pattern ...
Article

Romana sign

Romana sign, also known as chagoma, refers to periorbital swelling, palpebral oedema and conjunctivitis seen 1-2 weeks following infection with Trypanosoma cruzi (causative agent in the Chagas disease).  Romana sign is associated with ipsilateral regional lymphadenopathy.  History and etymolog...
Article

Salt and pepper sign - skull

Salt and pepper sign or pepperpot skull of the calvarium refers to multiple tiny well defined lucencies in the skull vault caused by resorption of trabecular bone in hyperparathyroidism. There is loss of definition between the inner and outer tables of the skull and a ground-glass appearance as...
Article

Sitting duck appearance

The sitting duck appearance denotes the normal anatomical configuration of the jugular foramen: the head of the duck (pointing backwards on the right side) represents the anteromedial pars nervosa the body of the duck representing the pars vascularis
Article

Steeple sign

The steeple sign, also called wine bottle sign, refers to the tapering of the upper trachea on a frontal chest radiograph reminiscent of a church steeple. The appearance is suggestive of croup, which should be obvious clinically. A corresponding lateral x-ray would show narrowing of the subglott...
Article

Stuck temporomandibular joint disc

A stuck disc refers to a TMJ disc which does not translate anteriorly out of the mandibular fossa onto the articular eminence, but rather remains (thus "stuck") in the fossa. It is a form of TMJ dysfunction and is typically associated with restricted range of motion. Treatment is wit...
Article

Thumb sign of epiglottitis

The thumb sign is a manifestation of an oedematous and enlarged epiglottis which is seen on lateral soft-tissue radiograph of the neck, and it suggests a diagnosis of acute infectious epiglottitis. This is the radiographic corollary of the omega sign 1-3.  Terminology Thumb sign is a term also...
Article

Thyroid inferno

Thyroid inferno refers to the colour Doppler appearance of the thyroid gland in active Graves disease (inclusive of variants such as Marine Lenhart syndrome), and consists of multiple small areas of colour flow seen diffusely throughout the gland representing increased vascularity and arterioven...
Article

Trumpeted internal acoustic meatus sign

A trumpeted internal acoustic meatus (IAM) is an indirect sign of an acoustic schwannoma and is useful in helping differentiating between one and other cerebellopontine angle entities, especially from a meningioma which typically does not extend into the meatus 1. It is characterized by widenin...
Article

Tullio phenomenon

The Tullio phenomenon describes the precipitation of vertigo and nystagmus by a loud noise. Aetiology The tympanic membrane and ossicular chain must be intact with a mobile footplate. It can be present in may situations congenital syphilis, with a semicircular canal fistula post-fenestratio...

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