Aniridia refers to either the clinical sign of a complete/partial absence of the iris, or more specifically to the disease entity classic aniridia. Rarely other genetic conditions may cause this sign.
Classic aniridia is inherited as an autosomal dominant condition and is seen in ...
Anisocoria is present when an individual's pupils differ in size. If a person's pupils are symmetric there is said to be isocoria.
The prevalence of transient physiological anisocoria of >0.4 mm is found in up to 20% population. However persistent anisocoria seems to be rarer, in ...
The ballet sign refers to the paralysis of voluntary movements of the eyeball with preservation of the automatic movements. Sometimes this sign is present with exophthalmic goiter and hysteria.
Battle sign is an eponymous term given to mastoid ecchymosis (bruising of the scalp overlying the mastoid process) and is strongly suggestive of a base of skull fracture, most commonly a petrous temporal bone fracture.
History and etymology
Mr William Henry Battle (1855-1936) was an English s...
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...
The broken heart sign describes the appearances of incudomalleolar disarticulation.
This sign is identified on CT in the coronal plane, being formed by the widening of the incudomalleolar joint and lateral displacement of the short process of the incus relative to the head of the malleus 1,2.
The Capps triad refers to the constellation of clinical and imaging findings in patients with spontaneous retropharyngeal hematomas, and consists of:
tracheal and esophageal compression
anterior displacement of the trachea
subcutaneous bruising over the neck and anterior chest
History and et...
Cloverleaf skull, also known as kleeblattschädel, refers to a type of severe craniosynostosis which gives the skull a cloverleaf shape. It is very rare, with less than 130 case reports globally. It typically results from intrauterine premature closure of the sagittal, coronal and lambdoid suture...
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...
A convoluted cerebriform pattern is a term used to denote the appearance of a 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 pre...
Thickening of the insertion of the lateral pterygoid muscle can mimic an anterior displaced temporomandibular 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.
The fistula test is used when examining a 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.g. cholesteat...
Garrington sign is thickening of the periodontal ligament/membrane space of involved teeth in the setting of gnathic osteosarcoma. Symmetrical widening of the space can be seen early in the disease process due to infiltration of tumor cells.
A geographic skull is a radiographic appearance which is seen in eosinophilic granuloma (EG) and characterized by destructive lytic bone lesions, the edges of which may be bevelled, scalloped or confluent.
Giraffe pattern (also known as the pseudonodular appearance) is a distinctive ultrasound appearance characteristic of Hashimoto thyroiditis. Bonavita originally described a thyroid gland with multiple echogenic nodules, separated from one another by bands of hypoechogenicity, reminiscent of a gi...
Griesinger sign, named after Wilhelm Griesinger, a German psychiatrist and neurologist (1817-1868) 3 refers to edema 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 ass...
The Guttman test is a clinical test 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.
The harlequin eye deformity is characterized by elevation of the superolateral corner of the orbit. It may be seen in unilateral (plagiocephaly) or bilateral (brachycephaly) coronal suture synostosis.
History and etymology
The term harlequin eye derives from the appearance of the eyes on a har...
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 Ménière disease.
It has been postulated that the vestibular stimulation is mediated by fibrous bands between foot...
The hockey stick sign can refer to a variety of different signs and appearances:
hockey stick sign (thyroid hemiagenesis)
hockey stick sign (Creutzfeldt-Jakob disease)
hockey stick sign (ureters)
Hockey stick sign has been used to describe the appearance of the thyroid gland in cases of thyroid hemiagenesis when investigated with thyroid scan (Tc-99m) 1. The unilateral lobe and isthmus make a shape reminiscent of a hockey stick.
hockey stick sign (Creutzfeldt-Jakob disease)
The Holman-Miller sign (also called the antral sign) is seen in juvenile nasopharyngeal angiofibroma; it refers to the anterior bowing of the posterior wall of the maxillary antrum as seen on a lateral skull radiograph or cross-sectional imaging 1,2.
This is a non-specific sign that can be prod...
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 external nasal branch of the nasociliary nerve (branch of the ophthalmic division of the trigeminal nerve) and thu...
Hutchinson 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:
History and etymology
Hyoid elevation on a modified barium swallow study indicates that the pharyngeal muscles are contracting appropriately.
Modified barium swallow
With real time fluoroscopy (or videofluoroscopy) during the act of swallowing, the larynx moves upward and forward when there i...
The ice cream cone sign may refer to:
the appearance of the head of malleus and the body and short process of the incus on axial CT scan: failure of this normal configuration suggests incudomalleolar dysarticulation
the ball of the ice cream is formed by the head of the malleus and cone is for...
Kayser-Fleischer rings, sometimes shortened to K-F rings, are caused by copper deposition in the cornea and are a specific, clinical sign of Wilson disease.
They are usually brown or dark reddish in color. Early on they may need a slit lamp to be visible before they becom...
The term kissing carotids refers to tortuous and elongated vessels which touch in the midline. They can be be found in:
within the pituitary fossa
within sphenoid sinuses
within sphenoid bones
The significance of kissing carotids is two-fold:
may mimic intr...
Low attenuation lymphadenopathy suggests underlying necrosis and can be seen in:
metastatic carcinoma (or lymphoma)
infections (tuberculous or fungal)
inflammatory necrotic disorders (e.g. Kikuchi-Fujimoto disease)
extra adrenal myelolipoma
The lyre sign refers to the splaying of the internal and external carotid by a carotid body tumor. Classically described on angiography it is also visible on CT angiography.
The Martini glass sign describes the appearance of the globe in persistent hyperplastic primary vitreous (PHPV).
On MRI the retrolenticular tissue characteristic of this condition has a triangular shape, like that of a martini glass appearing as low T2 signal against the normal high T2 signal o...
Morning glory disc anomaly (MGDA), also known as morning glory syndrome, is a rare congenital malformation of the optic nerve which is frequently associated with midline abnormalities of the brain and skull 1.
Morning glory disc anomaly is rare and is more commonly found in female...
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.
A perilymphatic fistula (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 fistu...
Polycoria is the presence of more than one true pupil in the iris, each possessing their own fully functional sphincter pupillae muscle, which responds appropriately to light and drugs. It is a very rare entity with only a few case reports in the global literature 1,2. Pseudopolycoria occurs whe...
The 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 spi...
Ptosis (or blepharoptosis) is a drooping or falling of the upper eyelid. Complete ptosis is due to complete oculomotor nerve palsy. Partial ptosis is due to a dysfunction of the sympathetic pathway leading to paralysis of Muller muscle.
Note that facial nerve paralysis prevents screwing of the...
Raccoon eyes sign (or panda eyes in the UK and Ireland) is due to periorbital ecchymosis and is specific for base of skull fracture of the anterior cranial fossa.
However it is not pathognomonic for trauma, and there are several rare causes described, including metastatic neuroblastoma, Kaposi ...
The raindrop skull appearance of calvarial multiple myeloma is the presence of multiple, well-defined lytic lesions (punched out lesions) of various size scattered throughout the skull. This term is applied as an analogy to rain hitting a surface and splashing, where it leaves a random pattern o...
Romana sign, also known as chagoma, refers to periorbital swelling, palpebral edema and conjunctivitis seen 1-2 weeks following infection with Trypanosoma cruzi (causative agent in Chagas disease).
Romana sign is associated with ipsilateral regional lymphadenopathy.
History and etymology
The sack of marbles sign refers to aggregations of multiple small globules of fat within a cyst mimicking marble spheres within a sack. They appear hyperechoic on ultrasound, fat attenuation on CT, and high signal on T1WI and T2WI on MRI. It is considered highly suggestive of a dermoid cyst 1.
Salt and pepper sign or pepper pot skull refers to multiple tiny well-defined lucencies in the calvaria caused by resorption of trabecular bone in hyperparathyroidism. There is a loss of definition between the inner and outer tables of the skull and a ground-glass appearance as well as spotty de...
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
Snake eyes, also known as snail eyes, is a term used to refer to the appearance of the facial nerve on coronal CT within its canal in the petrous temporal bone as the tympanic segment doubles back next to the labyrinthine segment. Anteriorly, these two segments converge at the geniculate ganglio...
A stuck disc refers to a temporomandibular joint (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.
The thumb sign in epiglottitis is a manifestation of an edematous 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.
Thumb sign is ...
Thyroid inferno refers to the color 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 color flow seen diffusely throughout the gland representing increased vascularity and arteriovenou...
Trousseau sign of latent tetany (not to be confused with Trousseau syndrome) is highly specific for hypocalcemia 1. It may be elicited by placing a blood pressure cuff over the upper arm and inflating to above systolic pressure for 2-3 minutes. This reduces arterial supply to the forearm. The is...
A trumpeted internal acoustic meatus (IAM) is an indirect sign of an acoustic schwannoma and is useful in helping to differentiate between one and other cerebellopontine angle entities, especially from a meningioma which typically does not extend into the meatus and is more often associated with...
The Tullio phenomenon describes the precipitation of vertigo and nystagmus by a loud noise.
The tympanic membrane and ossicular chain must be intact with a mobile footplate. It may be seen in several situations:
superior semicircular canal dehiscence syndr...
Widow's peak hair anomaly refers to a frontal hairline projection.
Prominent V-shaped hairline projection. Ocular hypertelorism might be...