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.
1,099 results found
Article
Dot in box appearance
A "dot in box" appearance is a pattern that has been described with pulmonary lymphangitis carcinomatosis. The interlobular septal thickening from lymphangitis forms polygonal arcades accounting for the box while the prominence of the centrilobular bronchovascular bundle is thought to represent...
Article
Rigler notch sign (lungs)
The Rigler notch sign refers to an indentation in the border of a solid lung mass, which is thought to represents a feeding vessel, thus suggesting the presence of a bronchial carcinoma 1. However, this sign is also observed in other conditions, including granulomatous infections, and its differ...
Article
Figure of eight appearance
The following lesions may resemble a figure of eight (sometimes referred to as snowman shaped):
supracardiac variety of total anomalous pulmonary venous return 1
pituitary macroadenoma with suprasellar extension 2
intraspinal neurofibroma with extraspinal extension through neural for...
Article
Dark bronchus sign
The dark bronchus sign is the appearance of a relatively darker bronchus as compared to adjacent ground glass opacity. Normally, the density of lung parenchyma and the bronchiolar lumen is similar. In cases of ground glass opacity, the bronchiolar lumen within the affected lung parenchyma appear...
Article
Y sign (epidural lipomatosis)
The Y sign refers to a common appearance in lumbar epidural lipomatosis where excess fat in the extradural space compresses the dural sac into the shape of the letter "Y".
NB: Y sign also refers to the appearance of incudomalleolar disarticulation on CT, more commonly known to radiologists as t...
Article
Manta ray sign (bladder)
The manta ray sign is a radiographic appearance in bladder exstrophy. It describes wide midline separation of the pubic bones simulating the appearance of a manta ray swimming towards you 1. The sacrum and iliac wings recall the manta ray’s head and body, with the widely spaced pubic rami formin...
Article
Panzerherz (heart)
Panzerherz (or armoured heart) is a term used to describe the appearance of the heart in calcified constrictive pericarditis.
The pericardium becomes circumferentially thickened with calcification, limiting the ability of the heart to contract. The rim of dense calcification describes how the h...
Article
Silhouette sign (x-rays)
Silhouette sign is somewhat of a misnomer and in the true sense actually denotes the loss of a silhouette, thus, it is sometimes also known as loss of silhouette sign or loss of outline sign 4.
The differential attenuation of x-ray photons by two adjacent structures defines the silhouette, e.g...
Article
Chorionic bump
Chorionic bump is a finding that can be uncommonly seen in a first-trimester scan. It may represent a small hematoma bulging into the gestational sac or an anembryonic (failed) second pregnancy that is being resorbed. It is also seen in some patients undergoing infertility treatment.
Epidemiolo...
Article
Chang sign (pulmonary embolism)
The Chang sign refers to the dilatation and abrupt change in caliber of the main pulmonary artery due to pulmonary embolism 1. It is one of several described signs of pulmonary embolus on chest radiographs.
History and etymology
It is named after C H Joseph Chang, (7 July 1929 - 15 November 20...
Article
Aubergine sign (penis)
The aubergine sign (also known as egg-plant sign or deformity) is a clinical sign of a fractured penis. Hemorrhage beyond the tunica albuginea produces swelling and bruising of the penis simulating the appearance of an aubergine.
Article
Napkin-ring sign (heart)
The napkin-ring sign is a feature of high-risk coronary artery atherosclerotic plaque on CT coronary angiogram (coronary CTA). It has been shown to possess a high predictive value in predicting future cardiac events and is considered one of the imaging correlates of an unstable plaque.
It is n...
Article
Bucket handle appearance (disambiguation)
Bucket handle appearance is used in imaging to refer to several different entities:
bucket handle fracture - non-accidental injury
bucket handle fracture of the pelvis
bucket handle meniscal tear
bucket handle mesenteric injury
Article
Westermark sign
Westermark sign is a sign of pulmonary embolus seen on chest radiographs. It is one of several described signs of pulmonary embolus on chest radiographs.
Pathology
The theory behind the sign is either obstruction of the pulmonary artery or distal vasoconstriction in hypoxic lung 3.
In one stu...
Article
Disproportionate posterior horn sign (meniscal tear)
The disproportionate posterior horn sign is a feature described with a meniscal tear having a posteriorly flipped fragment.
Pathology
Bucket handle tears of meniscus of the knee joint constitute 10% of meniscal tears. They consist of a vertical or longitudinal tear (which includes vertical-obl...
Article
Hyperattenuating ring sign (epiploic appendagitis)
The hyperattenuating ring sign is a sign that has been described with epiploic appendagitis and refers to a hyperattenuating ring of visceral peritoneum surrounding an inflamed epiploic appendage 1. On CT it can be seen as a ring of soft tissue surrounding a region of fat attenuation adjacent to...
Article
Tattoo sign (mammogram)
The tattoo sign is a feature given to describe dermal calcifications seen on mammography 1. The basis of this sign is that dermal calcifications maintain fixed relationships to one another that are reproducible with similar projections at different times. This is in contrast to intramammary calc...
Article
Ring of fire sign (adnexa)
The ring of fire sign, also known as ring of vascularity, signifies a hypervascular lesion with peripheral vascularity on color or pulsed Doppler examination of the adnexa due to low impedance high diastolic flow 1.
This sign can be seen in:
corpus luteum cyst (more commonly)
ectopic pregnancy
Article
Scham sign (hip)
The Scham sign of slipped capital femoral epiphysis is one of the subtle signs that may be seen on the AP view of an adolescent hip radiograph with early slip.
In the normal adolescent hip, an intra-articular portion of the diaphysis of the collum overlies the posterior wall of the acetabulum i...
Article
Interface sign (HRCT chest)
The interface sign is a feature seen on HRCT chest imaging and refers to the presence of irregular interfaces at the margins of pulmonary parenchymal structures or the pleural surface of the lung. It suggests interstitial thickening.
Article
Egg-on-a-string sign (heart)
Egg-on-a-string sign, also referred to as egg on its side, refers to the cardiomediastinal silhouette seen in transposition of the great arteries (TGA).
The heart appears globular due to an abnormal convexity of the right atrial border and left atrial enlargement and therefore appears like an ...
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
White pyramid sign (kidney)
The white pyramid sign, also known as dense renal medulla sign (DRM) or hyperdense renal pyramids sign, refers to the CT appearance of the medullary pyramids of the kidney which can be seen normally on unenhanced CT scans as high-attenuation triangular structures.
Pathology
Etiology
incidenta...
Article
Lucent liver sign
The lucent liver sign is represented by a reduction of hepatic radiodensity on supine radiograph when there is a collection of free intraperitoneal gas located anterior to the liver.
Article
Hitchhiker thumb deformity
Hitchhiker thumb deformity is a musculoskeletal manifestation of rheumatoid arthritis presenting in the thumb, with the combination of:
flexion of the metacarpophalangeal (MCP) joint
hyperextension of the interphalangeal (IP) joint
Terminology
Hitchhiker thumb deformity, also known as Z-thum...
Article
Molar tooth sign (abdomen)
The abdominal molar tooth sign refers to the appearance of contrast media which has spilled out of the urinary bladder on CT cystography after extraperitoneal bladder rupture.
Contrast flows out of the ruptured bladder, occupying the preperitoneal cavum Retzii and surrounds the bladder in the s...
Article
Coin lesion (lung)
A coin lesion refers to a round or oval, well-circumscribed solitary pulmonary lesion. It is usually 1-5 cm in diameter and calcification may or may not be present 1,3. Typically but not always the patient is asymptomatic 1.
Differential diagnosis
The differential diagnosis for such lesions i...
Article
Empty light bulb sign (brain death)
In brain death, on Tc-99m HMPAO imaging there is absent or reduced flow in the internal carotid arteries and increased flow within the external carotid arteries. This leads to absent uptake in the brain with subsequent increased perfusion in the nasal region. This appearance has been called the ...
Article
Snowman sign (total anomalous pulmonary venous return)
Snowman sign refers to the configuration of the heart and the superior mediastinal borders resembling a snowman. This is seen in total anomalous pulmonary venous return (TAPVR) type I (supracardiac type). It is also referred to as the figure of 8 sign.
It is an abnormality of the fetal circulat...
Article
Bullet-shaped vertebra
Bullet-shaped vertebra, also known as ovoid 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
progressive pseudorheumatoid dysplasia 4
Wils...
Article
Weapon and munition inspired signs
Weapon and munition inspired signs include the following with their corresponding pathologic conditions:
arrowhead sign
appendicitis
bayonet artifact
bayonet deformity
Turner syndrome
chondrodysplasia
bullet-shaped vertebra
mucopolysaccharidosis
achondroplasia
cannonball metastases
me...
Article
Mondor sign (foot)
The Mondor sign is a sign seen clinically and on CT, and refers to a hematoma that is formed and extends distally along the sole of the foot 1. Its presence is considered pathognomonic for a calcaneal fracture 1.
History and etymology
It was named after Henri Mondor (1885-1962), a French surge...
Article
Fleischner sign (tuberculosis of ileocecal junction)
The Fleischner sign (also known as the inverted umbrella sign), refers to a widely gaping, thickened, patulous ileocecal valve and a narrowed, ulcerated terminal ileum associated with tuberculous involvement of the ileocecum.
See also
gastrointestinal tuberculosis
Stierlin sign
not to be con...
Article
Stierlin sign (tuberculosis of ileocecal junction)
The Stierlin sign refers to repeated emptying of the cecum, seen radiographically as barium remaining in the terminal part of the ileum and in the transverse colon. This occurs due to irritation of the cecum caused by M. tuberculosis. It is not specific for tuberculosis and can also be seen in C...
Article
Sandwich sign (Marchiafava-Bignami disease)
The sandwich sign of Marchiafava-Bignami disease has been described for the appearance of the central layers of the corpus callosum which are preferentially involved by this disease.
T2 and FLAIR hyperintensities are seen in the central region of body and splenium of corpus callosum with sparin...
Article
Thoracoabdominal sign
Thoracoabdominal sign, a variation of the silhouette sign, is a frontal chest radiograph sign which helps to localize a thoracic lesion.
Since the posterior costophrenic sulcus is more caudal than the anterior lung, a thoracic lesion must be posterior if its caudal end is visible below the dome...
Article
Medial stripe sign
The medial stripe sign refers to an area of increased lucency at the interface of the medial lung and the mediastinum on a chest radiograph in a case of medial pneumothorax. A small pneumothorax generally accumulates anteriorly or medially which may be difficult to detect, hence this sign holds ...
Article
Hatchet sign (ankylosing spondylitis)
The hatchet sign refers to the limited erosion of the lateral aspect of the humeral head that produces a hatchet-shaped deformity. This finding is typically associated with ankylosing spondylitis.
In the absence of osteoporosis and the presence of sclerosis, this sign helps to differentiate it ...
Article
Onion bulb formation
Onion bulb formation is a histopathologic finding in hypertrophic neuropathies such as Charcot-Marie-Tooth type 1A (CMT1A) and chronic inflammatory demyelinating polyneuropathy (CIDP).
Pathology
Onion bulb formations are concentric layers of Schwann cell processes and collagen surrounding axon...
Article
Rolling stone sign
The rolling stone sign refers to the presence of gallstones within the gallbladder that are mobile when the patient moves.
Small gallstones can sometimes be difficult to diagnose due to the absence of posterior shadow artefact but the presence of a rolling stone sign increases the confidence of...
Article
Snowcap sign (osteonecrosis)
Snowcap sign, or snowcapping, is defined as the appearance of dense sclerosis over the head of the humerus or femur in cases of osteonecrosis as seen on plain radiographs, which resembles a snowcapped mountain.
Article
Nubbin sign
Nubbin sign (also called as cystic duct sign) is an important sign in a HIDA scan (cholescintigraphy using iminodiacetic acid analogs) that may be seen in cases of gallbladder neck obstruction. The "nubbin" refers to a small amount of radiotracer activity in the cystic duct, with absence of trac...
Article
Shifting granuloma sign
Shifting granuloma sign refers to a shift in the location of a parenchymal lesion visible on prior films that may be seen in the presence of atelectasis.
For example, this occurs when a calcified granuloma is present in a lung and a significant parenchymal collapse "shifts" it from one location...
Article
Light bulb sign (pheochromocytoma)
The light bulb sign of an adrenal pheochromocytoma is an MRI feature of this tumor. It refers to marked hyperintensity on T2 weighted sequences, however, this finding is neither sensitive nor specific and pheochromocytomas are more often heterogeneous with intermediate or high T2 signal intensit...
Article
Light bulb sign (hepatic hemangioma)
The light bulb sign of a hepatic hemangioma is a feature than can be seen on MRI imaging with a classic hepatic hemangioma. This refers to marked hyperintensity seen on heavily T2 weighted sequences that has been likened to a glowing light bulb.
See also
light bulb sign - shoulder
light bulb ...
Article
Pronator quadratus sign
The pronator quadratus sign, also known as MacEwan sign, can be an indirect sign of distal forearm trauma. It relies on displacement of the fat pad that lies superficial to the pronator quadratus muscle as seen on a lateral wrist radiograph.
Pathology
Displacement, anterior bowing, or oblitera...
Article
Teardrop sign (ankle)
The ankle teardrop sign is one of the radiological signs of an ankle joint effusion. It represents the presence of excess fluid in the inferior part of the anterior compartment of the ankle.
Pathology
Etiology
trauma
gout
rheumatoid arthritis
synovitis
septic arthritis
Radio...
Article
Teardrop sign (superior mesenteric vein)
The teardrop sign of the superior mesenteric vein is one of the important signs in the local staging of pancreatic adenocarcinoma. Its importance lies in its diagnostic, as well as prognostic, significance. This sign is used in assessing the resectability of pancreatic cancer.
Radiographic feat...
Article
Pseudogallbladder sign
Pseudogallbladder sign is a sonographic feature that can be seen in some children with biliary atresia.
Radiographic features
Ultrasound
Appears as a cystic structure seen in the liver which is confused with gallbladder in a few cases of biliary atresia. In these patients it is an important f...
Article
Nodule-in-nodule appearance (liver)
In hepatic imaging, a nodule-in-nodule appearance represents foci of abnormal arterial enhancement within a liver lesion, in cases of a liver regenerative nodule with a focus of hepatocellular carcinoma or high-grade dysplastic nodule. It is so called because of the nodular arterial enhancement ...
Article
Mushroom cap sign (endometriosis)
The mushroom cap sign is one of the important signs of deep rectosigmoid endometriosis seen on T2 weighted MRI sequence. It indicates the submucosal involvement in the rectosigmoid colon. The hypertrophic muscularis propria appears as heterogeneous low signal intensity surrounded by the high sig...
Article
Shmoo sign
Shmoo sign refers to the appearance of a prominent, rounded left ventricle and dilated aorta on a plain PA chest radiograph giving the appearance of Shmoo, a fictional cartoon character in the comic strip Li'l Abner, which first appeared in 1948 5. This sign is indicative of left ventricular enl...
Article
Eggshell calcification (breast)
Eggshell calcifications in the breast are benign peripheral rim like calcifications
Pathology
They are typically secondary to fat necrosis or calcification of oil cysts.
Radiographic features
thin rim-like calcification (<1 mm in thickness)
lucent centers
small to several centimeter...
Article
Punctate microcalcification within the breast
Punctate microcalcifications within the breast are defined as calcific opacities <0.5 mm in diameter seen within the acini of a terminal ductal lobular unit.
Epidemiology
Associations
fibrocystic changes
skin calcification
skin talc
rarely in DCIS: punctate, clustered, segmentally distribu...
Article
Popcorn calcification within the breast
Popcorn calcification in the breast is the classical description for the calcification seen in involuting fibroadenomas which, as the name suggests, has a popcorn-like appearance.
Pathology
A fibroadenoma in the long run may degenerate and calcify. Initially, there are a few punctate peripher...
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 the talocalcaneal subtype of tarsal coalition. It can be seen in both osseous and non-osseous coalition.
Radiographic appearance
A continuous C-shaped arc on a lateral ankle radiog...
Article
Tangential calcium sign
A tangential calcium sign is a sign seen with an aortic aneurysm rupture. The calcified intimal rim is discontinuous and is seen to tangentially point away from the aneurysmal lumen. This sign is seen at the point of breach. There is associated retroperitoneal leakage.
Article
Threads and streaks sign
The threads and streaks sign refers to an angiographic appearance of a vascularized tumor thrombus extending into the ipsilateral renal vein or the inferior vena cava from a renal cell carcinoma. This gives an appearance of linear, thread-like or string-like appearance of the involved vessel.
...
Article
Spaghetti sign (bladder)
The spaghetti sign may be seen in upper urinary tract bleeding.
It refers to the presence of a linear worm- or spaghetti-like filling defect within a contrast-opacified bladder 1,2. This linear filling defect represents blood clot extruded from the ureter and thereby molded into a tubular shape...
Article
Extrapleural sign
The extrapleural sign refers to the appearance of a pulmonary opacity with oblique margins that taper slowly to the chest wall when the lesion is viewed tangentially to the x-ray beam. This appearance suggests that the lesion is pleural or extrapleural in nature, as opposed to intrapulmonary whe...
Article
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...
Article
Maiden waist deformity
A maiden waist deformity or sign is a name given to the appearance when there is medial deviation of both ureters. This typically occurs in retroperitoneal fibrosis. In this condition, there is medial indrawing of the ureters due to deposition of fibrous tissue in the retroperitoneum at the leve...
Article
Kidney sweat sign
The kidney sweat sign refers to the presence of thin, hypoechoic, extracapsular fluid collections around kidneys in renal failure patients. This fluid is thought to represent perirenal edema. It can be appreciated on ultrasound, CT and MRI.
Differential diagnosis
perirenal hematoma
perirenal...
Article
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...
Article
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.
Article
Renal arterial cut-off sign
Renal arterial cut-off sign, as the name suggests, is an abrupt termination of the contrast-opacified lumen of the renal artery. It may or may not be associated with contrast extravasation.
It is seen in a vascular injury, e.g. segmental or main renal artery thrombosis or occlusion.
Article
Female prostate sign
Female prostate sign is a characteristic imaging sign seen in patients with a large urethral diverticulum.
A large urethral diverticulum in females surrounds the urethra, and elevates the base of the bladder, mimicking the typical appearance of enlarged prostate in males.
Article
Beak sign (pyloric stenosis)
Beak sign in pyloric stenosis is one of the fluoroscopic (barium meal) findings that is useful in the diagnosis of congenital hypertrophic pyloric stenosis.
Terminology
The term bird's beak sign is used in a number of other contexts: see bird beak sign (disambiguation).
Radiographic features
...
Article
Tulip bulb sign
The tulip bulb sign refers to the characteristic appearance of annuloaortic ectasia as seen on CT angiography.
There is symmetric dilatation of the three sinuses of Valsalva, with extension into the ascending aorta and effacement of the sinotubular junction.
It is seen especially in Marfan sy...
Article
Perirenal cobweb
Perirenal cobwebs are the presence of prominent perinephric septa. It is best appreciated on CT images.
Pathology
The cobweb is considered to be due to engorged venous collaterals or due to edema and fluid extravasation into the perirenal space 1.
Perirenal cobwebs may be seen in many benign ...
Article
Cookie bite bone metastases
Cookie bite bone metastases are characterized by small focal eccentric lytic external cortical destruction in long tubular bones. This type of destruction is typically described for metastases from lung cancer, however, they can also occur with other tumors.
Article
Lying down adrenal sign
The lying down adrenal sign is a cross-sectional imaging sign of renal agenesis or ectopia in which the ipsilateral adrenal gland appears to be 'lying down' on the psoas muscle posteriorly. Due to the linear as opposed to Y-shaped configuration of the gland in such situations, it is also describ...
Article
Girdlestone procedure
The Girdlestone procedure (also known as a femoral head ostectomy or Girdlestone resection arthroplasty) is an excision arthroplasty of the hip. The procedure inevitably results in limb shortening.
Indications
peri-prosthetic infection
aseptic loosening
recurrent dislocation
failed interna...
Article
Intracranial arterial beading
Intracranial arterial beading represents alternating areas of constriction in the intracranial arteries that gives the appearance of beads strung together.
Differential diagnosis
The various conditions where this may be seen are:
cerebral vasculitis
radiation therapy
cerebral vasospasm post...
Article
Extrapleural air sign (pneumomediastinum)
The extrapleural air sign is one of the many signs of pneumomediastinum, and was first described by Lillard and Allen in 1965. It is defined as the presence of gas between the parietal pleura and the diaphragm. On a lateral projection, the gas forms a radiolucent pocket of gas posterior to the d...
Article
CT comma sign (head)
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
Gut signature sign
The gut signature sign is an ultrasound term used to describe the appearance of the gastrointestinal wall.
Radiographic features
Ultrasound
The bowel wall has five layers, composed of alternating hyperechoic and hypoechoic appearances. Anatomically these layers are as follows (innermost to o...
Article
Snake eyes (facial nerve)
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...
Article
Double delta sign (meniscal tear)
The double delta sign is a feature that has been described in a bucket handle meniscal tear when the inner meniscal fragment flipped anteriorly adjacent to the anterior horn of the donor site and is referred to as a displaced bucket handle tear. The original location of the posterior horn remain...
Article
Dual rim sign (brain abscess)
The dual or double rim sign is seen on MRI in approximately 75% of cerebral abscesses and is helpful in distinguishing an abscess from a glioblastoma.
On both susceptibility weighted imaging (SWI) and T2WI it consists of two concentric rims surrounding the abscess cavity, outer one of which is...
Article
Raindrop skull
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...
Article
Fleck sign (foot)
The fleck sign in the foot is a small bony fragment seen in the Lisfranc space (between the base of the 1st and 2nd metatarsal) associated with avulsion of the Lisfranc ligament (at the base of the 2nd metatarsal or the medial cuneiform). It is a very subtle, but important finding since it predi...
Article
Disappearing basal ganglia sign
The disappearing basal ganglia sign is one of the early signs of a middle cerebral artery (MCA) infarction. It is defined as the loss of delineation of the basal ganglia, due to blurring of their grey-white matter interface and hypoattenuation, consequent to cytotoxic edema at the time of an isc...
Article
Morning glory sign (midbrain)
Morning glory sign of progressive supranuclear palsy (PSP) and multisystem atrophy, not to be confused with morning glory syndrome, refers to the appearance of the midbrain on axial imaging 1.
Graphically this is identified on an axial image at the level of the midbrain by drawing 1:
a horiz...
Article
Fluid sign (vertebral collapse)
The fluid sign is one of the radiological features of osteoporotic fractures, and can be helpful in distinguishing them from metastatic vertebral fractures, as it is seen more often in osteoporotic fractures and is rarely seen in metastatic fractures 1. It is not as helpful as identifying a para...
Article
CT angiographic spot sign (intracerebral hemorrhage)
The spot sign is a CTA sign in acute intracerebral hemorrhage and representing the focal accumulation/pooling/extravasation of contrast containing blood within the hematomas. It is an important feature to identify during the evaluation of acute intracerebral hemorrhage as it significantly increa...
Article
Roberts sign (fetal demise)
Roberts sign refers to the presence of a gas shadow within the heart or the greater vessels, in cases of fetal death in utero. It is a rare sign caused by postmortem blood degeneration, usually seen 1-2 days after death; and may be seen as early as 12 hours.
History and etymology
First describ...
Article
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...
Article
Bright rim sign (disambiguation)
The bright rim sign on MRI can refer to
bright rim sign in DNETs
bright rim sign in ATFL injury 1
putaminal rim sign
Article
Intrahepatic arterioportal shunt
Intrahepatic arterioportal shunts represent abnormal flow between the portal venous system and a hepatic arterial system within the liver. They can be a reversible cause of portal hypertension.
Clinical presentation
Clinical features will depend on the size and other underlying pathology. Smal...
Article
Gallbladder ghost triad
Gallbladder ghost triad is a term used on ultrasound studies when there is a combination of three gallbladder features on biliary atresia:
atretic gallbladder, length less than 19 mm
irregular or lobular contour
lack of smooth/complete echogenic mucosal lining with an indistinct wall
The te...
Article
Cheerio sign (shoulder)
The Cheerio sign has been described as a sign seen in a type III superior labral anterior posterior tear (SLAP lesion) of the glenoid labrum. In the Cheerio sign, a rounded core of soft tissue is surrounded by a rim of contrast material and gas.
SLAP type III is the bucket handle tear of the s...
Article
Cheerio sign (pulmonary nodule)
Cheerio sign in thoracic imaging relates to pulmonary nodules with a central lucent cavity supplied by a patent bronchus as seen on CT 3. It is due to proliferation of (malignant or non-malignant) cells around an airway. They are so named because of their resemblance to the breakfast cereal, Che...