Items tagged “signs”

24 results found
Article

Positive metacarpal sign

In the metacarpal sign, a line drawn along the heads of the 4th and 5th metacarpals will intersect the head of the 3rd metacarpal if shortening is present. The shortened 4th metacarpal is the key to the sign. The sign is positive in up to 9.6% of normal individuals 3. It is however seen in a va...
Article

Open ring sign

The open ring sign is a relatively specific sign for demyelination, most commonly multiple sclerosis (MS), and is helpful in distinguishing between the causes of ring-enhancing lesions.  Radiographic features The enhancing component is thought to represent advancing front of demyelination and ...
Article

Caput medusae sign (developmental venous anomaly)

The caput medusae sign, refers to developmental venous anomalies of the brain, where a number of veins drain centrally towards a single drain vein. The appearance is reminiscent of Medusa, a gorgon of Greek mythology, who was encountered and defeated by Perseus. The sign is seen on both CT and ...
Article

Fallen fragment sign

The fallen fragment sign refers to the presence of a bone fracture fragment resting dependently in a cystic bone lesion. This finding is said to be pathognomonic for a simple (unicameral) bone cyst following a pathological fracture. Although it has occasionally been reported with other cystic le...
Article

Pancake brain

Pancake brain, is the classical sign of alobar holoprosencephaly. It is due to fusion of the cerebral hemispheres leaving a single ventricle in its center. It is the most severe form of holoprosencephaly. It is associated with multiple facial abnormalities. See also pancake vertebra vegetable...
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

Bare orbit sign (sphenoid wing)

The bare orbit sign, is described as a characteristic appearance of the orbit, seen when the innominate line is absent. The innominate line is a projection of the greater wing of the sphenoid, and its absence or destruction is responsible for this appearance. It is the classical frontal radiogr...
Article

Leopard skin sign (white matter)

The leopard skin sign (also known as tigroid pattern or stripe sign) results from dark-spots or stripes (spared perivascular white matter) within bright demyelinated periventricular white matter on T2W images. It is characteristically seen in: metachromatic leukodystrophy Pelizaeus-Merzbacher ...
Article

Tau sign

The tau sign represents the appearance of a persistent trigeminal artery on the sagittal plane of an angiogram or on sagittal MRI images. It resembles the greek letter τ, pronounced 'tau'. Persistent trigeminal artery arises from the junction between the petrous and cavernous ICA and runs poster...
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CT comma sign

The CT comma sign is a characteristic sign seen in head trauma. It is the presence of concurrent epidural and subdural hematomas, which gives the characteristic appearance of this sign as a "comma" shape.
Article

Shmoo sign

Shmoo sign refers to the appearance of a prominent, rounded left ventricle and dilated aorta on a plain AP chest radiograph giving the appearance of Shmoo, a fictional cartoon character in the comic strip Li'l Abner, which first appeared in 1948. This sign is indicative of left ventricular enlar...
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Snowcap sign (avascular necrosis)

Snowcap sign or snowcapping is defined as the appearance of dense sclerosis over the head of humerus or femur in cases of avascular necrosis as seen on plain radiographs, which resembles a snowcapped mountain.
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Sandwich sign (Marchiafava-Bignami disease)

Sandwich sign of Marchiafava-Bignami disease is described as the appearance due to the involvement of central layers of the corpus callosum. T2 and FLAIR hyperintensities are seen in the central region of body and splenium of corpus callosum with sparing of peripheral dorsal and ventral layers ...
Article

Bilateral adrenal gland hyperenhancement

Bilateral adrenal gland hyperenhancement or intense adrenal enhancement may be a feature of hypotension and forms part of the CT hypoperfusion complex. Adrenal gland hyperenhancement has been described in pediatric and small adult series or individual cases of hemorrhagic shock, pancreatitis, s...
Article

Double axillary pouch sign

The double axillary pouch sign is a collection of fluid between a torn anteroinferior glenoid labrum and the glenoid rim, giving the appearance of a second axillary pouch. The sign is seen best with MR arthrography on the coronal view, and is considered by some, a very specific sign for an ante...
Article

Higoumenakis sign (clavicle)

Higoumenakis sign is the unilateral enlargement of the sternal end of the clavicle in patients with late congenital syphilis. Pathology Treponema pallidum becomes readily localized in the lymphatic spaces and may remain in the connective tissues without manifestation in childhood. Through mech...
Article

Sliver sign (patella)

The sliver sign refers to a curvilinear intra-articular osteochondral fragment in the knee joint on conventional knee radiographs. In the context of acute knee trauma and in association with joint effusion this sign is highly predictive of a recent transient lateral patellar dislocation 1. Path...
Article

Double Oreo cookie sign (glenoid labrum)

The double Oreo cookie sign refers to the presence of two hyperintense lines in the superior glenoid labrum, one of which represents a superior labral tear and the other a physiological sublabral recess 1, 2. This pattern is likened to an Oreo cookie with two layers of (white) cream and three l...
Article

Pooping duck sign

Pooping duck sign indicates the presence of a triquetral fracture, 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 the poop dorsal to the duck. The ...
Article

Trident acetabulum

Trident acetabulum is an appearance which can be seen in several skeletal dysplasias 1. It is characterized by small bony spurs at the medial and lateral acetabular margins with a more subtle central spur, resembling a trident, the three-pronged spear of classical Greece 1.  The appearance has...

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