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.

1,061 results found
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Contrast agent pooling sign

The contrast agent pooling sign is a CT sign characterized by dense intravenous contrast agent pooling in veins, and may signal imminent cardiac arrest. Radiographic features The contrast agent pooling sign is characterized by dense intravenous iodinated contrast media pooling and layering in ...
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Speed test (shoulder)

A speed test is a clinical tests in assessing the shoulder.  In this test examiner places the patient's arm in shoulder flexion, external rotation, full elbow extension, and forearm supination. Manual resistance is then applied by the examiner in a downward direction or the patient is asked to ...
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Feeding artery sign (endometrial polyp)

Feeding artery sign (a.k.a. pedicle artery sign) refers to the presence of a single feeding artery to endometrial lesion using color/power Doppler on ultrasonography. It is often seen in endometrial polyps 1. The feeding vessel indicates the stalk attachment of the polyp to the uterus. Endometr...
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Notch sign (primary CNS lymphoma)

The notch sign refers to abnormally deep depression at the tumor margin in contrast-enhanced MRI in primary CNS lymphoma 1. It is not an uncommon sign in primary CNS lymphoma and can be seen in both immunocompetent and immunocompromised patients. It suggests an irregular growth pattern as well a...
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Mickey Mouse sign (anencephaly)

The Mickey Mouse sign in obstetric ultrasound denotes the characteristic "floating appearance" of the fetal cerebral lobes due to the absence of the cranium due to anencephaly.  Radiographic features The sign is best seen in the coronal plane (in relation to the fetal head), where the cerebral...
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Frog eye sign

The frog eye sign is seen when the orbital structures show a characteristic protrusion due to fetal anencephaly. The term is particularly used in point of care ultrasound (POCUS) 1.  Radiographic features On obstetric ultrasound the frog eye sign is best appreciated in the coronal plane (in re...
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Harris ring

A Harris ring is a ring-like shadow observed at the base of the odontoid process on a lateral radiograph of the cervical spine. It is formed by the superimposition of the lateral masses of the C2 vertebra (axis) on its body. Disruption of the Harris ring is seen in type III, and less commonly, ...
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Superior triangle sign (right lower lobe collapse)

The superior triangle sign is seen with complete right lower lobe (RLL) collapse alone or combined with right middle lobe collapse on PA chest x-rays. This sign can be a useful indirect sign of right lower lobe collapse where typical features are absent. Radiographic features Plain radiograph ...
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V sign of interphalangeal joint dislocation

The V sign is characterized on a lateral radiograph of the digit by the separation of the dorsal base of the dislocated phalanx and the head of the phalanx proximal to the incongruent joint 1,2. Before reduction, the V sign might be assessed to identify more subtle dorsal subluxations 1. If th...
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Scaphoid abdomen

Scaphoid abdomen is the term given to an inward concavity of the anterior abdominal wall. It is used both for the clinical appearance and its radiological equivalent.  In children it maybe a sign of congenital diaphragmatic hernia. In both adult and pediatric patients, it raises the possibility...
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Coandă effect (physics)

The Coanda effect refers to the phenomenon by which a narrow jet of liquid (or air) passing through an orifice directly in sequence with a solid (especially convex) surface will deviate from its path and adhere to this curved surface, following its shape in parallel. The mechanism is thought to...
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Dragonfly sign

Dragonfly sign describes the appearance of the cerebellum on coronal images, which is seen secondary to cerebellar atrophy in pontocerebellar hypoplasia 1. The sign is so called as the whole cerebellum resembles the shape of a dragonfly if one imagines the vermis is the body of the insect and t...
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Collar sign in spondylolysis

The Collar sign in spondylolysis refers to a break in the pars interarticularis of the vertebra on oblique radiographs that can have the appearance of a collar around the Scotty dog's neck. unilateral or bilateral 90% seen at the L5 level and less than10% noted at the L4 level1,2 65% of patie...
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Mackler's triad

Mackler's triad consists of the clinical symptoms of vomiting, followed by severe pain in the chest, usually retrosternal, lower thoracic, and upper abdominal, associated with subcutaneous emphysema detected on physical examination, which is suggestive of esophageal rupture (Boerhaave syndrome) ...
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Anderson triad

The Anderson triad consists of the clinical findings of tachypnea and abdominal rigidity with lower thoracic or epigastric pain, associated with subcutaneous emphysema, which is usually related to esophageal rupture. 
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Sea anemone sign

The sea anemone sign is a unique (but not wholly exclusive) appearance seen in ovarian serous surface papillary borderline tumors (SSPBT). It refers to its surface stroma frequently branches into exophytic papillary stalks, macroscopically 1. Radiographic features On cross-sectional imaging, p...
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Comma sign of subscapularis tear

The comma sign of subscapularis tear was first described on arthroscopy but recognized later on MRI. The comma sign represents a full thickness partial width superior subscapularis tear along with torn superior glenohumeral and coracohumeral ligament insertional fibers vertically retracted via a...
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Tram-track sign (knee)

The tram-track sign refers to the posterior cruciate ligament (PCL) appearance when it has a diffuse or partial thickening of the anteroposterior diameter greater than 7 mm. It is associated with longitudinal intraligamentous signal abnormalities showing fluid signal characteristics (hyperintens...
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Bow-tie sign

"Bow-tie sign" refers to the appearance of rotated facets in unilateral facet joint dislocation. Facet joint displacement coupled with a rotational deformity gives a bow-like like appearance on a lateral view radiograph of spine 1.
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Talar shift

Talar shift is a concept, sign and/or measurement describing a displacement of the talus in relation to the articular surface of the distal tibia and the malleolar end segment. The direction of the talar shift is further described in the medical literature and lateral talar shift receives the mo...
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Lead pipe fracture

The term lead pipe fracture is the term for a radiographic appearance given to a simultaneous greenstick fracture of one side of the bone (usually metaphysis) with a buckle fracture of the opposing cortex of the same bone.  There are differing opinions in texts as to whether this term should be...
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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...
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Crescent sign (disambiguation)

The characteristic shape of the crescent has been given to many radiological signs over the years. crescent sign (disambiguation) crescent sign (arterial dissection) crescent sign (inguinal hernia) crescent sign (intravenous pyelogram) crescent sign (lung hydatid) crescent sign (osteonecro...
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Doughnut sign (missed testicular torsion)

The doughnut sign, also known as the bull's-eye, halo or ring sign, is the name of a distinctive appearance of a missed testicular torsion on scrotal scintigraphy.  In a missed torsion (i.e. established testicular infarction), there is a reactive hyperperfusion of the ipsilateral dartos muscle ...
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Joint mouse

A joint mouse (plural: joint mice) is a historical synonym for an intra-articular loose body. This evocative term predates the discovery of x-rays and originated in orthopedics. It derives from the way in which some intra-articular osteochondral fragments appeared to move rapidly around the insi...
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Corkscrew sign (diffuse esophageal spasm)

A corkscrew esophagus, also known as a rosary bead esophagus, is a classic appearance of distal esophageal spasm on a barium swallow. It is actually quite a rare appearance which is seen in <5% cases of distal esophageal spasm. The finding is caused by multiple tertiary (non-propulsive) contract...
Article

Bowler hat sign

The bowler hat sign refers to an appearance on a GI contrast study, which may be seen with both polyps and diverticula of the bowel. The filling defect produced by the pathology mimics the outline of a bowler hat. It was originally described for colonic lesions, but can be seen with lesions thro...
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Rice signs (disambiguation)

Two different radiological signs are named for their similarity in size and shape to grains of rice. rice bodies (intra-articular) rice grain calcification (cysticercosis)
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Onion signs (disambiguation)

​Due to its distinctive morphology and its layered internal structure the onion has given rise to a number of signs in imaging: onion bulb nerves: Charcot-Marie-Tooth type 1A and chronic inflammatory demyelinating polyneuropathies (CIDP) onion peel sign: pulmonary hydatid cyst onion skin peri...
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Salt and pepper noise (MRI artifact)

Salt and pepper noise, also known as impulse noise, has been used to describe the characteristic appearance of a certain artifact seen on MRI. The artifact looks like innumerable black and white pixels throughout the image. Smoothing filters are algorithms designed to diminish the noise whilst ...
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Salt and pepper sign (autosomal recessive polycystic kidney disease)

The salt and pepper sign has been given to the heterogeneous echotexture of the enlarged kidneys on ultrasound in children with autosomal recessive polycystic kidney disease (ARPCKD).
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Salt and pepper sign (Sjögren syndrome)

The salt and pepper sign has been used to describe the MRI appearance of the parotid gland in Sjögren syndrome. This pertains to a combination of punctate regions of calcification (pepper) and fatty replacement (salt) 1.
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Salt and pepper sign (paraganglioma)

The salt and pepper sign is used to describe a typical MRI appearance of some highly vascular tumors which contain foci of hemorrhage, typically a paraganglioma 1-3. The appearance is on T1-weighted sequences, and is made up of: punctate regions of hyperintensity = salt small flow voids = pepp...
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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...
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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

The crisscross sign

The crisscross sign is a fetal ultrasound sign that describes the normal relationship between the ventricular outflows tracts of the fetal heart. The left ventricular outflow tract (LVOT); represented by the take-off of the aorta (Ao) from the left ventricle, is perpendicular (90o) to the right ...
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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...
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Rib-within-a-rib appearance

Rib-within-a-rib appearance refers to a feature that may be present on plain radiographs of the patients with β thalassemia. As the name suggests, the ribs take on an appearance of having another rib superimposed. The phenomenon is usually visible in the anterior and middle segments of the ribs ...
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Northern lights phenomenon

The northern lights phenomenon represents an echogenic band slowly descending distal to the ultrasound transducer, and is exclusively seen during high mechanical index (MI) B-mode scanning after the administration of ultrasonic contrast media. It is not to be confused with prolonged heterogeneou...
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Pseudoneuroma sign (plantar plate tear)

The pseudoneuroma sign is an indirect sign of plantar plate tears at the metatarsophalangeal joint (MTPJ) on MRI. This sign refers to pericapsular ill-defined and eccentric to the intermetatarsal space soft tissue thickening and is helpful for raising the accurate diagnosis of a plantar plate te...
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Apical rocking

Apical rocking is a radiographic sign that might be seen either on echocardiography or cine imaging on cardiac MRI in the four-chamber view and refers to a movement of the cardiac apex in cardiac dyssynchrony. It is characterized by the following 1-3: short-timed movement of the apex towards th...
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Ram's horn sign

The Ram's horn sign, also known as Shofar sign, is the tubular, conical appearance of the stomach antrum seen on a barium meal. The stomach is less distensible and the curved conical appearance resembles the horn of a ram. This is seen in granulomatous disease, typically Crohn disease, but also...
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Rosenbach sign (disambiguation)

Rosenbach sign may refer to several different clinical signs: Rosenbach sign (AV regurgitation) Rosenbach sign (eye) Rosenbach sign (hemiplegia) History and etymology Ottomar Ernst Felix Rosenbach (1851-1907), a German physician born in Prussian County in Silesia, graduated from medicine in...
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Rosenbach sign (eye)

The Rosenbach sign of the eyes is a clinical sign of Graves disease. It consists of fine tremors of the eyelids when gently closed 1,2. History and etymology Ottomar Ernst Felix Rosenbach (1851-1907), a German physician born in Prussian County in Silesia, graduated from medicine in Breslau in ...
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Rosenbach sign (hemiplegia)

Rosenbach sign or phenomenon is a clinical sign described in hemiplegia.  The sign refers to the absence of an abdominal wall skin reflex when stroking the paralyzed side of a patient; conversely on the unaffected side, the reflex is normal 1. See also Rosenbach gave his name to two other cli...
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Rosenbach sign (aortic valve regurgitation)

Rosenbach sign is a clinical sign that is seen in severe aortic/tricuspid valve regurgitation. It is elicited as pulsation of the liver, during systole, and it is primarily due to the increased cardiac output and associated retrograde blood flow into the liver 1-3. See also Rosenbach also gave...
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Obturator sign

Obturator sign is a clinical sign of acute appendicitis, it is defined as discomfort felt by the subject/patient on the slow internal movement of the hip joint, while the right knee is flexed. It indicates an inflamed pelvic appendix that is in contact with the obturator internus muscle 1-3. Se...
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Steelpan sign (sigmoid volvulus)

The steelpan sign refers to the close resemblance of sigmoid volvulus on CT to the percussion instrument known as the steelpan. The steelpan, also known as steel drum or pan, is a Caribbean musical instrument invented in Trinidad and Tobago by the mid-1930s, which became very popular in Trinidad...
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Split-wall sign (sigmoid volvulus)

The split-wall sign is one of the signs of sigmoid volvulus. This sign is characterized by the separation of the walls of a single loop of the sigmoid colon due to the invagination of mesenteric fat between them. The intervening fat causes the loop to appear bilobed or C-shaped on axial images, ...
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Shrimp sign (progressive multifocal leukoencephalopathy)

The shrimp sign is an MRI marker of cerebellar progressive multifocal leukoencephalopathy, characterized by T2-hyperintensity in the cerebellar white matter abutting but sparing the dentate nucleus. The white matter lesion resembles a shrimp, with the dentate nucleus outlining the belly of the ...
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Kussmaul sign

Kussmaul sign is a clinical sign, seen as a paradoxical increase in the jugular venous pressure in response to inspiration. This is opposed to the normal physiological response of inspiration resulting in decreased jugular venous pressure 1. Pathology Etiology This sign typically arises secon...
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Boas sign

Boas sign is a clinical sign that is defined as hyperesthesia felt by the patient to light touch in the right lower scapular region or the right upper quadrant of the abdomen. It is classically seen in patients with acute cholecystitis. History and etymology Ismar Isidor Boas (1858–1938), was ...
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Carnett sign

The Carnett sign describes an examination finding used to distinguish pain arising from the abdominal wall from pain arising from within the abdomen itself. Eliciting the sign was described as a two-stage procedure. First the examiner locates the point of maximal tenderness through palpation of...
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Fothergill sign

The Fothergill sign describes an examination finding used to distinguish an abdominal wall mass from one arising in the abdomen itself. The sign is said to be present if a mass remains palpable and becomes fixed when the rectus muscles are contracted, such as when the patient lifts their head f...
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Blumberg sign

Blumberg sign is defined as discomfort on the manual application of tension over the abdomen observed by simultaneously watching the subjects face. On the removal of the examiner's hand the patient should be again asked whether he or she is feeling pain or not. It is expressive of peritoneal irr...
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Rovsing sign

Rovsing sign is commonly used to describe pain elicited in the right iliac fossa on deep palpation of the left iliac fossa.  It is used in clinical examination to detect peritoneal irritation in the right iliac fossa, most frequently associated with acute appendicitis. Most teaching erroneously...
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Aaron sign

Aaron sign is a clinical sign that is defined as a feeling of distress and pain in the epigastric, umbilical and praecordial regions, on steady pressure over McBurney point, it is suggestive of chronic appendicitis. History and etymology Charles Dettie Aaron (1866–1951) was an American gastroe...
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Clinical signs

Clinical signs are really important to know in radiology. They are part of the communication strategy that clinical colleagues use to tell us what they are thinking. As such, it is vital that we understand that: these signs exist what they mean how specific and sensitive they are (if known)
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Cullen sign

Cullen sign refers to superficial edema visible as periumbilical discolouration and is most commonly seen in patients with acute pancreatitis 1-3. Clinical presentation Clinically patients with pancreatitis present with epigastric pain that radiates to the umbilical/periumbilical region and th...
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Coiled catheter sign (ureter)

The coiled catheter sign is sometimes seen in transitional cell carcinoma of the ureter. When a retrograde ureteropyelogram is attempted in the afflicted ureter, the catheter tip is seen to coil in the dilated portion of the ureter distal to the obstruction 1. 
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Uhthoff phenomenon (multiple sclerosis)

Uhthoff phenomenon refers to the temporary exacerbation (lasting less than 24 hours) of neurological symptoms secondary to increases in body temperature. This phenomenon is experienced by multiple sclerosis patients, though it also occurs in other demyelinating diseases 1.  History and etymolog...
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Trigonum parietale (azygos lobe)

The trigonum parietale refers to a triangular opacity seen on chest radiograph that correlates with a small piece of extrapleural areolar tissue that lies between the layers of pleura in the fissure of an azygos lobe 1-4. It may be seen at the most superior portion of the azygos fissure and shou...
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Pumice stone sign

The pumice stone sign is a recently described distinctive imaging appearance of emphysematous osteomyelitis on CT described as clusters of greater than 3 distinct foci of intramedullary gas with irregularly irregular sizes ranging between 2 and 5 mm with resemblance to surface appearance of pumi...
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Blunting of the costophrenic angle

Blunting of the costophrenic angle (also known as blunting of the costophrenic sulcus) is a chest radiograph sign usually indicative of a small pleural effusion. It may be seen on either frontal or lateral erect projections. It has been found that approximately 200 mL pleural fluid needs to be p...
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Bird’s nest sign (lungs)

The bird’s nest sign refers to the appearance created by a reverse halo sign with associated irregular and intersecting areas of stranding or irregular lines within the area of ground-glass opacity 1. Both bird's nest sign and reverse halo signs are suggestive of invasive pulmonary fungal infec...
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Beak sign (gallbladder)

The beak sign of gallbladder volvulus describes tapering of the distended gallbladder lumen as it transitions to a fulcrum point at the pedicle, resembling a curved beak.  Terminology The term bird's beak sign is used in a number of other contexts: see bird beak sign (disambiguation). 
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Backfill

Backfill refers to intra-articular high signal intensity on T1 weighted images seen in axial spondylarthritis within the sacroiliac joint filling up excavated bone erosions 1. It has been characterized as a complete loss of the cortical bone within the sacroiliac joint at the anticipated locatio...
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Iris sign

The iris sign is the imaging appearance of deep medullary venous thrombosis/congestion-related white matter injury in neonates created by fan-shaped, outwards radiating hemorrhages or cytotoxic edema in the subcortical and periventricular cerebral white matter. The appearance resembles the flowe...
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Pancake organ (disambiguation)

A variety of organ abnormalities have been described as having an appearance similar to a pancake. pancake adrenal  pancake brain pancake kidney pancake vertebra
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Braid-like sign (spinal sarcoidosis)

The braid-like sign is an imaging pattern of sarcoidosis spinal cord involvement. It is characterized by a ventral subpial enhancement in the spinal cord.
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Tulip sign

The tulip sign is a sonographic clue for in-utero diagnosis of severe hypospadias. The configuration of a tulip is given by the severe curvature of the penis in association with the penoscrotal transposition of a bifid scrotum. History and etymology The tulip sign was first described in 2002 ...
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Walnut kernel microbleed pattern

The walnut kernel microbleed pattern along with the starfield pattern and corpus callosum diffusion restriction appears to be the most important imaging markers of cerebral fat embolism 1-3. In this pattern, there is a diffuse presence of round microbleeds (punctate focal hypointensities) of si...
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P sign

The alphabet P sign, or just P sign, is a sonographic finding in acute epiglottitis. Using point of care ultrasound (POCUS), on a longitudinal view at the level of the thyrohyoid membrane, a P-shaped hypoechogenicity is apparent. The curved portion of the P is formed from the edematous epiglotti...
Article

O sign

The O sign is a radiographic sign described in gastric band slippage. Normally, a correctly-sited laparoscopic gastric band lies such that its anterior and posterior margins are superimposed in the anteroposterior orientation and a oblong morphology is visible on a frontal radiograph.  When a g...
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Flip-flop renal enhancement

Flip-flop renal enhancement describes when an infarcted renal parenchyma alternates between hypoattenuation during the arterial phase, and hyperattenuation on the delayed phase of a contrast enhanced CT 1,2.  Terminology Flip-flop renal enhancement should not be confused with the flip-flop eff...
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Guitar pick sign (orbits)

Guitar pick sign refers to conical deformation (tenting) of the posterior ocular globe indicating severely increased intraorbital pressure (orbital compartment syndrome) Presence of a guitar pick sign on imaging is associated with acute and permanent visual damage.
Article

Flail leaflet

Flail leaflet or leaflet flail refers to an abnormally increased leaflet mobility of the atrioventricular valves associated with valvular prolapse and a systolic excursion of the leaflet tip or edge into the atria. Pathology Flail leaflet can be seen in leaflets of the mitral and tricuspid val...
Article

Optic nerve calcification

Optic nerve calcification is a rare radiological finding, with only a short differential diagnosis, many of which have only been described in isolated case reports 1-4. Differential diagnosis optic nerve meningioma optic nerve head drusen idiopathic dural optic nerve sheath calcification ca...
Article

String of pearls sign (watershed infarction)

The string of pearls sign is seen on diffusion-weighted imaging of T2/FLAIR as a series of rounded areas of signal abnormality adjacent to, but separate from, the lateral ventricle. This represents a deep border zone infarct between the penetrating cortical arteries and ascending perforating art...
Article

Bright band sign

The bright band sign is a sonographic sign found in the context of splenic infarction. It consists of highly hyperechoic linear-shaped bands within splenic infarct lesions of different ages 1. Histological examinations of spleens with the sign suggest it might be caused by preserved fibrous tr...
Article

Roesler sign

Roesler sign is the name given to the inferior rib notching seen in coarctation of the aorta. Although by no means pathognomonic, the sign is fairly specific. Although many other causes of inferior rib notching have been recorded most of them are very rare 1. Strictly-speaking it is only called...
Article

Jail bar sign (vertebral hemangioma)

The jail bar sign refers to the vertically striated appearance seen in vertebral hemangiomas due to thickening of the bony trabeculae. It is the sagittal and coronal correlate of the polka-dot sign observed on axial imaging. It is caused by replacement of normal cancellous bone by coarse, scler...
Article

Doughnut sign (chest)

The doughnut sign can be appreciated on the lateral chest radiograph of patients with mediastinal adenopathy, most commonly seen in pediatric patients with pulmonary tuberculosis infection1. The sign is made up of precarinal, subcarinal and retrocarinal lymph nodes which surround the radiolucen...
Article

Windswept knees

Windswept knees refer to the appearance of a bilateral knee joint deformity where one knee is in valgus and the other is in varus. The name describes the position of the knees if the wind blew across the legs of a patient, causing this evocatively-named appearance. Pathology Etiology Most cau...
Article

V sign (disambiguation)

Signs inspired by the letter V have been described in several different pathologies: inverted V sign (pneumoperitoneum) inverted V sign (spinal cord) Naclerio V sign (pneumomediastinum) V sign (interphalangeal joint subluxation)
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Delta sign (disambiguation)

The delta sign has been described in several different pathologies: delta sign (brain) empty delta sign (brain) double delta sign (MSK)
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T sign (disambiguation)

The T sign has been described in several different pathologies: T sign (obstetrics) upper T sign (brain) lower T sign (brain)
Article

Target sign (cholangiocarcinoma)

The target sign of cholangiocarcinoma refers to the appearance of intrahepatic mass-forming cholangiocarcinoma on DWI consisting of a centrally hypointense area and peripherally hyperintense rim. The presence of this sign favors cholangiocarcinoma over hepatocellular carcinoma. It is present in ...
Article

Periportal halo sign (MRI)

The periportal halo sign on liver MRI is a specific sign of primary biliary cholangitis (formerly primary biliary cirrhosis) that is characterized by rounded low signal intensity around portal venous branches, 5-10 mm in size, on T1- and T2-weighted images. These lesions are usually numerous, in...
Article

Meniscus sign (cholangiography)

The meniscus sign on cholangiography suggests impacted choledocholithiasis and is characterized by a concave cutoff of the lower common bile duct lumen. When a stone is impacted in the distal duct, fluid may not be visualized on the sides of the stone and therefore the contour of the duct termin...
Article

Pleural pointillism

Pleural pointillism is multiple high signal regions on b=1000 diffusion-weighted imaging but not at lower b-values. It can be a reliable tool allowing differentiation of malignant from benign pleural lesions and can help guide biopsy 1-3.  Its sensitivity is reported to be 93-100% and specificit...
Article

Follicular ring sign

The follicular ring sign is considered as a characteristic sonographic sign for early diagnosis of ovarian torsion 1. It is defined as prominent (1-2 mm thick) hyperechoic margin seen concentrically around the antral follicles of the torsed ovary, which are usually small (3‐ to 7‐mm) and periphe...
Article

Chain of lakes sign

The chain of lakes sign is a radiological finding describing the appearance of the pancreatic ducts in cases of chronic pancreatitis. Due to repeated inflammation, fibrosis occurs and results in damage and atrophy of the pancreatic tissue as well as dilatation and beading of the main pancreatic ...

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