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.

722 results found
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Abnormal bowel wall attenuation patterns

Abnormal bowel wall attenuation patterns on CT scan can be grouped under five categories: white enhancement gray enhancement water halo sign fat halo sign black attenuation The first three patterns are seen on contrast studies. White enhancement It is defined as uniform enhancement of th...
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Abnormally eccentric gestational sac

An eccentrically-located gestational sac towards the fundus of the uterus is the normal sonographic appearance; however an abnormally eccentric gestational sac on ultrasound may be apparent due to a number of causes They include interstitial ectopic pregnancy 1 normally implanted pregnancy in...
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Absent bow tie sign (knee)

The absent bow tie sign represents the loss of the normal appearance of the menisci on parasagittal MRI images, and is suggestive of meniscal injury. Normally the medial and lateral menisci appear as low signal bow-tie-shaped structures between the femoral condyles and tibial plateaux. As the n...
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Absent nasal bone

In fetal sonographic assessment, an absent nasal bone is a feature which can sometimes be used as an adjunctive marker for fetal aneuploidy. Radiographic assessment Antenatal ultrasound It is assessed on a midline sagittal view. In this section the nasal bone is often seen as a bright echogen...
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Accordion sign (colon)

The accordion sign is seen on CT examinations of the abdomen and refers to the similarity between the thickened oedematous wall of pseudomembranous colitis and the folds of an accordion. This appearance is the result of oral contrast being trapped between oedematous haustral folds and pseudomemb...
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Ace-of-spades sign (heart)

Ace-of-spades sign refers to the pathognomonic configuration of the left ventricle as seen in apical hypertrophy 1-3. It consists of marked ventricular wall thickening at the apex resulting in cavity narrowing at the apex with a relatively normal appearance of the mid-ventricular to basal wall ...
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Adie pupil

Adie pupil (also known as tonic pupil) is caused by idiopathic degeneration of the ciliary ganglion, which sometimes occurs following a viral or bacterial illness. It is usually unilateral and typically affects young females 1. Adie pupil represents a large dilated "tonic pupil", which does not...
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Air bronchogram

Air bronchogram refers to the phenomenon of air-filled bronchi (dark) being made visible by the opacification of surrounding alveoli (grey/white). It is almost always caused by a pathologic airspace/alveolar process, in which something other than air fills the alveoli. Air bronchograms will not ...
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Air crescent sign (lung)

An air crescent sign describes the crescent of air that can be seen in invasive aspergillosis, semi-invasive aspergillosis or other processes that cause pulmonary necrosis. It usually heralds recovery and is the result of increased granulocyte activity. In angioinvasive fungal infection, the no...
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Air trapping

Air trapping in chest imaging refers to retention of excess gas (“air”) in all or part of the lung, especially during expiration, either as a result of complete or partial airway obstruction or as a result of local abnormalities in pulmonary compliance. It may also sometimes be observed in norma...
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Andersson lesion

Andersson lesions refer to an inflammatory involvement of the intervertebral discs by spondyloarthritis. Epidemiology Rheumatic spondylodiscitis is a non-infectious condition that has been shown to occur in about 8% of patients with ankylosing spondylitis, as detected at radiography. Patholog...
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Angular interface sign

The angular interface sign is used to characterise an exophytic renal mass, in which the exophytic renal mass has an angular interface with the renal parenchyma. In other words, the exophytic lesion has a tapered pyramidal contour or definite apex within the renal parenchyma. Due to its high se...
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Animal and animal produce inspired signs

Animal and animal produce inspired signs may sound a little silly, but the radiology literature is replete with such signs, some more fanciful than others. Fish and seafood fish vertebra (also known as codfish vertebra): biconcave vertebrae as seen in osteoporosis fishtail deformity of the el...
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Ankle teardrop sign

Ankle teardrop sign is one of the radiological signs of an ankle joint effusion. It represents the presence of fluid in the inferior part of the anterior compartment of ankle. Pathology Aetiology trauma gout rheumatoid arthritis synovitis infectious arthritis Radiographic appearance Pla...
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Anteater nose sign (foot)

The anteater nose sign refers to an anterior tubular elongation of the superior calcaneus which approaches or overlaps the navicular on a lateral radiograph of the foot. This fancifully resembles the nose of an anteater and is indicative of calcaneonavicular coalition 1,2.  History and etymolog...
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Anterior bronchus sign

The anterior bronchus sign refers to the appearance of the anterior segmental bronchus of the upper lobes as seen on a frontal chest radiograph. Normal anatomy The anterior segment bronchus of the upper lobes courses anteriorly and laterally. When the orientation is predominantly anteriorly th...
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Anterior tibial translocation sign

The anterior tibial translocation sign or anterior drawer sign (a.k.a. anterior translation of tibia) is seen in cases of complete rupture of the anterior cruciate ligament, and refers to anterior translocation (anterior tibial subluxation) of the tibia relative to the femur of more than 7 mm 1. 
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Antral nipple sign

The antral nipple sign refers to redundant pyloric mucosa protruding into the gastric antrum and is seen in pyloric stenosis. See also cervix sign of pyloric stenosis target sign of pyloric stenosis shoulder sign of pyloric stenosis
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Antral pad sign

The antral pad sign is a feature seen on a spot radiograph of the upper gastrointestinal tract obtained with orally-administered contrast material. It refers to the extrinsic impression or indentation on the posteroinferior aspect of the antrum. The impression is generally arcuate and smooth, an...
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Apple core sign (colon)

The apple core sign, also known as a napkin ring sign (bowel), is most frequently associated with constriction of the lumen of the colon by a stenosing annular colorectal carcinoma. Differential diagnosis The appearance of the apple-core lesion of the colon also can be caused by other diseases...
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Apple core sign (femur)

The apple core sign has been used to describe the circumferential erosion of the femoral neck seen in synovial chondromatosis. Although this is the most common process that may lead to an apple core erosion of the femoral neck, this has also been observed with: pigmented villonodular synovitis ...
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Apple-peel intestinal atresia

Apple-peel intestinal atresia, also known as type IIIb or Christmas tree intestinal atresia, is a rare form of small bowel atresia in which the duodenum or proximal jejunum ends in a blind pouch and the distal small bowel wraps around its vascular supply in a spiral resembling an apple peel. Oft...
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Arcuate sign (knee)

The arcuate sign is often a subtle but important finding on knee x-rays and represents an avulsion fracture of the proximal fibula at the site of insertion of the arcuate ligament complex, and is usually associated with cruciate ligament injury (~90% of cases) 2. The fracture fragment is attache...
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Argyll Robertson pupil

Argyll Robertson pupil is usually bilateral and presents as bilaterally miotic and irregular pupils, which constrict briskly with accommodation but do not react to bright light therefore displaying light-near dissociation 1.  It is a highly specific sign of late neurosyphilis, however can also ...
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Arrowhead sign (caecum)

The arrowhead sign refers to the focal caecal thickening centred on the appendiceal orifice, seen as a secondary sign in acute appendicitis. The contrast material in the caecal lumen assumes an arrowhead configuration, pointing at the appendix.   The arrowhead sign is applicable only when enter...
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Atoll sign (liver MRI)

The atoll sign in hepatic imaging has been described when a liver lesion shows a peripheral rim of high T2 signal intensity with the centre of the lesion appearing isointense to the background of non-cirrhotic liver on T2WI mimicking an atoll. It is considered a characteristic sign of an inflamm...
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Atrial escape

Atrial escape refers to a chest x-ray sign of massive left atrial enlargement and is an exaggerated version of the double density sign.   Normally, the right border of the left atrium is not visible. As it enlarges it forms a distinct border projecting through the right heart shadow, medial to ...
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Aubergine sign (penis)

The aubergine sign (also known as egg-plant sign or deformity) is a clinical sign of a fractured penis. Haemorrhage beyond the tunica albuginea produces swelling and bruising of the penis simulating the appearance of an aubergine.  
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Baastrup syndrome

Baastrup syndrome (also referred to as kissing spines) results from adjacent spinous processes in the lumbar spine rubbing against each other and resulting in hypertrophy and sclerosis with focal midline pain and tenderness relieved by flexion and aggravated by extension.  Epidemiology It tend...
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Backwash ileitis

Backwash ileitis is seen in patients with ulcerative colitis (UC), where the entire colon is involved. In such cases the terminal ileum is oedematous. Backwash ileitis extends contiguously backward from the caecum without skip regions. One source estimates it to occur in 6% of patients with UC,...
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Ball of wool sign (hydatid cyst)

The ball of wool sign, also referred to as the yarn sign or congealed water lily sign, is an ultrasound appearance, representing degeneration of hydatid cysts (WHO class CE 4). The inner side of the cyst detaches from the cyst wall and folds on itself, causing a change from anechoic (fluid) to a...
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Ballet sign

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 goitre and hysteria.
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Balloon on a string sign (ureter)

The balloon on a string sign refers to the appearance of the ureter on intravenous urography in ureteropelvic junction obstruction. It is seen due to the high and eccentric point of the exit of ureter from a dilated renal pelvis. 
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Bamboo spine

Bamboo spine is a radiographic feature seen in ankylosing spondylitis that occurs as a result of vertebral body fusion by marginal syndesmophytes. It is often accompanied by fusion of the posterior vertebral elements as well.  A bamboo spine typically involves the thoracolumbar and/or lumbosacr...
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Banana sign (cerebellum)

The banana sign is one of the many notable fruit inspired signs. It is seen on axial imaging through the posterior fossa of the fetus and is associated with the Chiari II malformation. It describes the way the cerebellum is wrapped tightly around the brain stem as a result of spinal cord tether...
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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...
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Bat wing 4th ventricle

Bat wing 4th ventricle sign refers to the morphology of the fourth ventricle in the Joubert anomaly and related syndromes. The absence of a vermis with apposed cerebellar hemispheres give the fourth ventricle an appearance reminiscent of a bat with its wings outstretched. It is best demonstrate...
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Bat wing opacities (lungs)

Bat's wing or butterfly pulmonary opacities refer to a pattern of bilateral perihilar shadowing. It is classically described on a frontal chest radiograph but can also refer to appearances on chest CT 3-4. Differential diagnosis Bat's wing pulmonary opacities can be caused by: pulmonary oedem...
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Bayonet deformity

Bayonet deformity is a term used to describe the shape of the wrist in certain conditions: Madelung deformity hereditary multiple exostosis with pseudo-Madelung deformity retarded bone growth of the distal ulna with outward bowing of the radius with distal radioulnar joint subluxation Colles...
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Beak sign (arterial dissection)

The beak sign of arterial dissection represents a wedge of haematoma at the distal end of the false lumen. It is here that false lumen propagation is occurring. It manifests as an acute angle between the dissection flap and the outer wall. It may be filled with contrast-enhanced blood (high atte...
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Beak sign (pyloric stenosis)

Beak sign in pyloric stenosis is one of the fluoroscopic (barium meal) findings which is useful in the diagnosis of congenital hypertrophic pyloric stenosis.  Radiographic features Barium meal A beak-like tapering projection of barium is seen entering into the narrowed and compressed pyloric ...
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Bear paw sign (kidney)

The bear paw sign is seen in xanthogranulomatous pyelonephritis and refers to the cross-sectional appearance of the kidney which is said to resemble the paw of a bear. The renal pelvis is contracted whereas the calyces are dilated, mimicking the toe-pads of the paw.
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Beck triad

Beck triad is a collection of three clinical signs associated with pericardial tamponade which is due to an excessive accumulation of fluid within the pericardial sac. The three signs are: low blood pressure (weak pulse or narrow pulse pressure) muffled heart sounds  raised jugular venous pre...
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Big rib sign

The big rib sign is a sign to differentiate right and left ribs on lateral chest radiographs.  It exploits a technique of magnification differences on lateral projections between right and left ribs. For example, on right lateral projections the left ribs appear larger than right ribs.  This s...
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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 paediatric and small adult series or individual cases of haemorrhagic shock, pancreatitis,...
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Bird beak sign (disambiguation)

Bird beak sign is used in many contexts to denote a rapid tapering to a point, reminiscent of a bird's beak. Described bird beak signs include:  beak sign (arterial dissection) beak sign (pyloric stenosis) bird beak sign (oesophagus) bird beak sign (right colon) bird beak sign (sigmoid colo...
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Bird beak sign (oesophagus)

The bird's beak sign of the oesophagus is used to refer to the tapering of the inferior oesophagus in achalasia. The same appearance (although it is difficult to see the similarity) is also referred to as the rat-tail sign. The appearance, although classically occurring in primary achalasia, ca...
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Bird beak sign (right colon)

The bird beak sign of the right colon is tapering obstruction of the inferior part of right colon seen on contrast enema or CT scan with rectal contrast indicating caecal volvulus. This sign can help to differentiate caecal volvulus from caecal bascule, in particular on a contrast/barium enema ...
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Bird beak sign (sigmoid colon)

Bird's beak sign of the sigmoid is one of the signs of sigmoid volvulus. It represents gradual narrowing/tapering of sigmoid colon up to the level of obstruction during contrast/barium insertion to the rectum or on CT. When located in the sigmoid colon, it suggests the diagnosis of sigmoid volv...
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Black turbinate sign (nasal cavity)

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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Blade of grass sign (Paget disease)

The blade of grass sign, also called the candle flame sign, refers to the lucent leading edge in a long bone seen during the lytic phase of Paget disease of bone.  The blade of grass sign is characteristic of Paget disease of bone. This is akin to osteoporosis circumscripta cranii seen in the s...
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Blend sign (brain)

The blend sign refers to a CT appearance of early intracranial haematoma growth. It is defined as blending of a hypoattenuating area and a hyperattenuating region with a well-defined margin.
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Bone within a bone appearance

Bone within a bone is a descriptive term applied to bones that appear to have another bone within them. There are numerous causes including: normal thoracic and lumbar vertebrae (neonates and infants) growth recovery lines (after infancy) cortical splitting and new periostitis sickle cell d...
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Boomerang sign (knee)

The boomerang sign is defined as a small displaced flap from a longitudinal horizontal type medial meniscal tear which is displaced inferiorly into the medial meniscotibial recess. The imaging diagnosis of this type of tear is crucial because it is normally hidden from the surgeon during routine...
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Boomerang sign (splenium)

The boomerang sign refers to a boomerang-shaped splenial lesion (splenium of corpus callosum) which is seen as a hyperintense lesion on T2-WI, FLAIR and DWI 1. This sign can be seen in: transient lesion of the splenium ischaemia posterior reversible encephalopathy syndrome (PRES) diffuse ax...
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Bouchard node

Bouchard nodes are a clinical sign relating to bony nodules of the the proximal interphalangeal joints, and are much less common than Heberden nodes. They generally (but not always) correspond to palpable osteophytes. Clinical presentation They are sometimes painful, and are typically associat...
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Bouquet of flowers appearance (medullary sponge kidney)

A bouquet of flowers appearance is a description given to the appearances of medullary sponge kidney on a traditional intravenous pyelogram (IVP) study. The ectatic distal collecting ducts contain the microcalcifications typical of the disease. This is also known as the bunch of grapes appearanc...
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Boutonniere deformity

Boutonniere deformity is one of the musculoskeletal manifestations of rheumatoid arthritis in the hand with: flexion contracture of the proximal interphalangeal (PIP) joints extension of the distal interphalangeal (DIP) joints  The defect appears in the tendon which splays open. The appearanc...
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Box-shaped heart

A box-shaped heart is a radiographic description given to the cardiac silhouette in some cases of Ebstein anomaly. The classic appearance of this finding is caused by the combination of the following features: huge right atrium that may fill the entire right hemithorax shelved appearance of th...
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Bracket sign (pars marginalis)

The bracket sign of the pars marginalis, also known as the pars bracket sign, refers to the appearances of the superior most extent of the pars marginalis of the cingulate sulcus on axial imaging. It forms two roughly symmetric brackets, open anteriorly. The next sulcus anteriorly is the central...
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Bracket sign (pericallosal lipoma)

The bracket sign refers to a radiographic appearance seen with the tubulonodular variety of pericallosal lipoma. It reflects calcification seen at the periphery of the midline lipoma. It is best seen on coronal imaging and historically was identified on frontal radiographs. It should not be con...
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Breast within a breast sign

The breast within a breast sign refers to the common mammographic appearance of breast hamartomas (fibroadenolipomas). Since these benign lesions are well-circumscribed and contain a mixture of fibrous, glandular and fatty tissue (just like normal breast), it is not surprising that they appear v...
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Bridging vessel sign

The bridging vessel sign refers to an appearance of vessels coursing from the uterus into an adjoining pelvic mass (a vascular bridge). This sign helps to differentiate a pedunculated subserosal uterine leiomyoma from other juxtauterine masses of ovarian, adnexal or bowel origin. Colour and pow...
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Bright dot sign (atypical liver haemangioma)

The bright dot sign refers to the presence of a bright dot within a lesion which remains hyperattenuating on arterial and portal venous phase CT, corresponding to early nodular enhancement seen on dynamic MRI of liver haemangioma.  This can be used as an indicator that the lesion in question is...
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Bright rim sign (anterior talofibular ligament injury)

The bright rim sign in anterior talofibular ligament injury refers to a sign seen on MRI. A cortical defect with a bright dot-like or curvilinear high-signal-intensity, usually at the fibular attachment site, is seen on MRI. It has been described as an indicator of ATFL injury 1. See also brig...
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Bright rim sign in dysembryoplastic neuroepithelial tumours

The bright rim sign has been described in dysembryoplastic neuroepithelial tumours (DNETs) and is seen, as the name so aptly describes, as a rim of high signal around the DNET on FLAIR sequences.
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Bronchial cut-off sign

The bronchial cut-off sign refers to the abrupt truncation of a bronchus from obstruction, which may be due to cancer, mucus plugging, trauma or foreign bodies. Typically, there is associated distal lobar collapse. 
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Bronchorrhoea

Bronchorrhoea is the expectoration of copious amounts of mucus from the lungs. It has been defined as production of more than 100 mL of mucus in 24 hours, which is more than is usually seen in chronic lung disease (e.g. chronic bronchitis typically produces 25 mL/24 hrs) 2. It may be a feature o...
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Brudzinski sign (meningism)

Brudzinski sign occurs in meningitis (of any aetiology) where passive flexion of one leg causes flexion in the opposite leg. Passive flexion of the neck brings about flexion of the legs as well. Historical context First described by Jósef Brudziñski (1874-1917), paediatrician from Warsaw, Pola...
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Bubbly consolidation

Bubbly consolidation describes internal or central lucencies which represent normal aerated lung lobule within infarcted, consolidated, lung parenchyma. It is one of the highly specific imaging appearances of focal pulmonary haemorrhage or possibly pulmonary infarct secondary to pulmonary emboli...
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Bulging fissure sign

The bulging fissure sign refers to lobar consolidation where the affected portion of the lung is expanded. It is now rarely seen due to the widespread use of antibiotics. The most common infective causative agents are 1: Klebsiella pneumoniae: Klebsiella pneumonia Streptococcus pneumoniae: pn...
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Bullet and bodkin sign

Bullet and bodkin sign is the appearance of the ureter when there is an abrupt transition in the ureteral caliber. Bullet in the name is represented by the dilated proximal ureteric segment which appears to be perched on the constricted / non-dilated encased ureter which gives an appearance of a...
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Bullet-shaped vertebra

Bullet-shaped vertebra refers to the anterior beaking of the vertebral body. It is seen in the following conditions: mucopolysaccharidosis (Morquio disease, Hurler disease) achondroplasia congenital hypothyroidism  See also weapons and munitions inspired signs
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Bunch of grapes sign (disambiguation)

Bunch of grapes sign refers to the ultrasound appearance of multiple cystic spaces or lesions and it has been described in a number of settings: within the uterus as a result of hydropic swelling of trophoblastic villi within a hydatidiform mole in bronchiectasis, where on a chest radiograph, ...
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Butterfly glioma

Butterfly gliomas are a high grade astrocytoma, usually a glioblastoma (WHO grade IV), which crosses the midline via the corpus callosum. Other white matter commissures are also occasionally involved. The term butterfly refers to the symmetric wing-like extensions across the midline.  Most freq...
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Butterfly sign (choroid plexus)

The butterfly sign refers to the normal appearance of the choroid plexuses on axial imaging of the fetal brain, commonly observed on the antenatal ultrasound. Its absence may suggest holoprosencephaly 1. In the CNS, the term should not be confused with a butterfly glioma, which is a glioblastom...
Article

Butterfly vertebra

Butterfly vertebra is a type of vertebral anomaly that results from the failure of fusion of the lateral halves of the vertebral body because of persistent notochordal tissue between them. Pathology Associations an anterior spina bifida, with or without an anterior meningocele can be part of...
Article

Button sequestrum

A button sequestrum is a small sequestrum of devascularised bone surrounded by lucency. Although classically described in osteomyelitis and eosinophilic granuloma it is also occasionally seen in fibrosarcoma and lymphoma. Differential diagnoses osteoid osteoma tuberculous osteitis radiatio...
Article

C sign (talocalcaneal coalition)

The C sign is an important radiological sign which may be seen on a lateral radiograph of the ankle in those with a tarsal coalition (talocalcaneal coalition).  Radiographic appearance A continuous C-shaped arc is seen on a lateral ankle radiograph which is formed by the medial outline of the ...
Article

Caecal bar sign

The caecal bar sign is a secondary sign in acute appendicitis. It refers to the appearance of inflammatory soft tissue at the base of the appendix, separating the appendix from the contrast-filled caecum. See also arrowhead sign
Article

Callosal angle

The callosal angle has been proposed as a useful marker of patients with idiopathic normal pressure hydrocephalus (iNPH), helpful in distinguishing these patients from those with ex-vacuo ventriculomegaly (see hydrocephalus versus atrophy).  Method Ideally the angle should be measured on a cor...
Article

Calyceal crescent sign

The calyceal crescent sign (Dunbar crescents) refers to the early intravenous pyelogram (IVP) appearance of markedly dilated renal calyces. It is formed by early contrast opacification of the dilated collecting ducts and ducts of Bellini with the characteristic shape as a result of the associate...
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Cannonball metastases (lungs)

Cannonball metastases refer to large, well circumscribed, round pulmonary metastases that appear, well, like cannonballs. The French term "envolée de ballons" which translates to "balloons release" is also used to describe this same appearance. Metastases with such an appearance are classically...
Article

Capps triad

The Capps 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 History and ...
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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 ...
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Caput medusae sign (portal hypertension)

The caput medusae sign is seen in patients with severe portal hypertension. It describes the appearance of distended and engorged paraumbilical veins, which are seen radiating from the umbilicus across the abdomen to join the systemic veins.  History and etymology The appearance is reminiscent...
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Cardiac chamber enlargement

Cardiac chamber enlargement can be recognised by cardiac contour changes, new or different interfaces with adjacent lung, and/or displacement of adjacent mediastinal structures. These are discussed separately: right atrial enlargement right ventricular enlargement left atrial enlargement lef...
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Carman meniscus sign

The Carman meniscus sign describes the lenticular shape of barium in cases of large and flat gastric ulcers, in which the inner margin is convex toward the lumen. It usually indicates a malignant ulcerated neoplasm; in cases of benign gastric ulcers, the inner margin is usually concave toward th...
Article

Cartilage interface sign

Cartilage interface sign, also referred to as double cortex sign, refers to the sonographic presence of a thin markedly hyperechoic line at the interface between the normally hypoechoic hyaline articular cartilage of the humeral head and an abnormally hypoechoic supraspinatus tendon. This arises...
Article

Caton-Deschamps index (knee)

The Caton-Deschamps index is a ratio that is used in everyday practice as well as in research to measure patellar height and allows the diagnosis of patella alta and patella baja. Radiographic features The Caton-Deschamps index is the ratio between the distance between the lower pole of the pa...
Article

Celery stalk metaphysis

Celery stalk metaphysis refers to a plain film appearance of the metaphyses in a number of conditions characterised by longitudinally aligned linear bands of sclerosis. They are seen in: congenital infections congenital rubella congenital syphilis congenital cytomegalovirus (CMV) osteopathi...
Article

Celery stalk sign (anterior cruciate ligament)

The celery stalk sign is a term given to the appearance of the anterior cruciate ligament which has undergone mucoid degeneration and has been likened to that of a celery stalk. Its low signal longitudinal fibres are separated from each other by higher signal mucinous material, best appreciated ...
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Centipede sign (mesentery)

The centipede sign is seen as engorged mesenteric vessels in cases of acute sigmoid diverticulitis which gives an appearance similar to a centipede 1.

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