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Reynolds pentad

Reynolds pentad is a combination of clinical signs found in acute cholangitis. It consists of Charcot triad 2-4: fever and/or chills RUQ pain jaundice as well as: delirium or lethargy, and shock Usefulness Sensitivity of Reynolds pentad from a large systematic review of nine studies was ...

Enlarged hilar periportal space sign

The enlarged hilar periportal space sign refers to the widening of the periportal space seen on MRI in early liver cirrhosis. Usage Enlarged hilar periportal space sign is one of the early signs of cirrhosis and may be used to detect fibrotic changes in the liver in patients who do not yet hav...

Zebra sign (disambiguation)

The evocative appearance of the coat of a zebra has been used for several distinctive signs in radiology: zebra sign: cerebellar hemorrhage 1 zebra sign: amyotrophic lateral sclerosis 2 zebra spleen: arterial phase appearance of normal spleen 4,5 zebra stripe sign: treated osteogenesis imper...

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...

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...

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).

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 ...

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...

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...

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 ...

Exclamation mark sign (limy bile)

The exclamation mark sign is a pathognomonic imaging sign of the rare diagnosis of limy bile on plain abdominal radiography. It occurs when there is both limy bile and a gallstone in the common bile duct. The linear vertical radiopaque bile forms the line of the exclamation mark (i.e. !), whilst...

Starry sky appearance (disambiguation)

Starry sky appearance is a radiological sign used to describe the appearance of the liver on two different imaging modalities: starry sky appearance (ultrasound) starry sky appearance (MRI) starry sky artifact (MRI)

Caput medusae sign (disambiguation)

Caput medusae sign can refer to: caput medusae sign (portal hypertension) caput medusae sign (developmental venous anomaly) History and etymology The appearance is reminiscent of Medusa, a gorgon of Greek mythology, who was encountered and defeated by Perseus.

Starry sky appearance (MRI)

Starry sky appearance on MRI refers to the appearance of small innumerable T2 hyperintense bile duct hamartomas and biliary microhamartomas, scattered throughout the T2 hypointense hepatic parenchyma, which resembles a “starry sky”. The high T2 signal lesions represent Von Meyenburg complexes se...

Astronomical inspired signs

Many signs in radiology have been inspired by astronomical phenomena: comet tail (disambiguation) comet tail artifact (ultrasound) color comet tail artifact comet tail sign (chest) comet tail sign (phleboliths) earth-heart sign galaxy sign (chest) loss of half-moon overlap sign milky wa...

Cluster sign

The cluster sign is a finding on MRI and CT that is associated with pyogenic hepatic abscesses and can help differentiate pyogenic abscesses from other types of liver lesions. Radiographic features The cluster sign is best seen on MRI T2-weighted and postcontrast T1-weighted sequences. Small n...

Spider web appearance

Spider web appearance is a classic appearance seen on venography in a patient with hepatic venous outflow obstruction. It refers to the dense network of hepatic venous collaterals seen.

Serpent sign

The serpent sign, a.k.a. snake sign, is described in hydatid disease. The WHO classification (2001) or Gharbi classification (1985) of hydatid disease describe several stages on ultrasound 1. During the active stage, the cyst is composed of three layers: the outer (pericyst), the middle (ectocy...

Round belly sign (abdominal compartment syndrome)

Round belly sign is a sign of increased abdominal pressure of greater than 20 mmHg in abdominal compartment syndrome where the abdomen has a rounded appearance of transverse section on CT, rather than its typical oval shape. The sign is positive when the AP to transverse diameter of the abdomen...

Charcot triad

Charcot triad is the finding of pyrexia, right upper quadrant pain and jaundice, and is a traditional clinical sign of acute cholangitis. A meta-analysis of 4288 patients in 16 studies found that the sensitivity of Charcot triad for acute cholangitis was poor (36.3%) with a much better specific...

Lollipop sign (hepatic epithelioid hemangioendothelioma)

The lollipop sign is seen in hepatic epithelioid hemangioendothelioma (HEHE). It represents hepatic/portal vein and/or their tributaries/branches tapering and terminating at or just within the edge of a well defined peripherally enhancing (or non-enhancing) lesion with an avascular core on CT or...

Intrabiliary rupture of hepatic hydatid cyst

Intrabiliary rupture of hepatic hydatid cyst is a common complication associated with hepatic hydatid cysts. It is important to appreciate the direct and indirect signs of this condition. Radiographic features The radiological features of intrabiliary rupture of a hepatic hydatid cyst can be c...

Right posterior hepatic notch sign

The right posterior hepatic notch sign is a sharp indentation of the normally smooth posterior right hepatic lobe margin. It is associated with cirrhosis, although the mechanism is not entirely clear. It has been suggested that this may be an indication of relative caudate lobe hypertrophy and d...

Turtleback sign

Turtleback sign, also known as tortoise shell appearance, represents a characteristic appearance of chronic hepatic schistosomiasis in which liver margins are irregular and nodular. Dystrophic calcifications within a polygonal network of fibrous septa are seen in the periphery, often perpendicul...

Double target sign (hepatic abscess)

The double target sign is a characteristic imaging feature of liver abscess on contrast-enhanced CT scans, in which a central, fluid-filled low attenuation lesion is surrounded by a high attenuation inner rim and a low attenuation outer ring 1,2. The inner ring (abscess membrane) demonstrates e...

Target sign (tuberculosis)

The target sign of tuberculosis refers to the bull's eye appearance of some parenchymal tuberculomas involving the brain (see: CNS tuberculosis) and solid abdominal organs (see: hepatic and splenic tuberculosis) on cross-sectional imaging. Radiographic features Ultrasound hypoechoic nodules ...

Tensile gallbladder fundus sign

The tensile gallbladder fundus sign is positive when the gallbladder fundus is seen to bulge into, and distort, the anterior abdominal wall and is a feature of acute cholecystitis. It is particularly useful as an early sign of the condition on CT as it has around a 75% sensitivity and 95% speci...

Courvoisier sign (hepatobiliary)

Courvoisier sign or Courvoisier-Terrier sign states that in a patient with painless jaundice and an enlarged gallbladder (or right upper quadrant mass), the cause is unlikely to be gallstones and therefore presumes the cause to be an obstructing pancreatic or biliary neoplasm until proven otherw...

Reverse target sign (cirrhotic nodules)

A reverse target sign is a potential ultrasound marker for cirrhotic nodules on ultrasound. It represents central iso-hyperechogenicity with surrounding hyperechoic rim. This sign is useful to differentiate metastases from cirrhotic nodules, conversely the target sign is seen with liver metastas...

Atoll sign (disambiguation)

The atoll sign in radiology can refer to: reverse halo sign: atoll sign in thoracic CT atoll sign in liver MRI: suggestive of an inflammatory hepatic adenoma

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 center of the lesion appearing isointense to the background of non-cirrhotic liver on T2WI mimicking an atoll. The peripheral rim shows hyperenhancement in the por...

Focal hepatic hot spot sign

The focal hepatic hot spot sign, also known as the hot quadrate sign can be seen on technetium 99m sulfur colloid scans of the liver and spleen, as well as CT studies. Radiographic features It occurs as a focal area of increased radiopharmaceutical uptake, or iodinated contrast accumulation, i...

Double barrel sign (disambiguation)

Double barrel sign is an imaging appearance of two lumens adjacent to each other. It can be seen in: dilated bile duct adjacent to portal vein double barrel aorta: aortic dissection double barrel esophagus: esophageal dissection

Duct penetrating sign (pancreas)

Duct penetrating sign is a radiographic sign that can be useful in differentiating between focal pancreatitis (inflammatory pancreatic mass) from pancreatic carcinoma. A positive sign is when a mass is penetrated by an unobstructed pancreatic duct; this makes focal pancreatitis the most likely ...

Three line sign (common bile duct)

The three line sign refers to an MRI term that describes the appearance of roundworm Ascaris lumbricoides within the CBD lumen which appears as two hypointense lines representing the worm walls and hyperintense center which represents the worm gut. See also biliary ascariasis

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...

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...

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 ...

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...

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 ...

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...

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...

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...

Sonographic Murphy sign

Sonographic Murphy sign is defined as maximal abdominal tenderness from pressure of the ultrasound probe over the visualized gallbladder 1,2. It is a sign of local inflammation around the gallbladder along with right upper quadrant pain, tenderness, and/or a mass 2. It is one of the most import...

Starry sky appearance (ultrasound)

A starry sky appearance , also known as a centrilobular pattern 7, refers to a sonographic appearance of the liver parenchyma in which there are bright echogenic dots throughout a background of decreased liver parenchymal echogenicity. Although usually associated with acute hepatitis, this sign ...

Wall-echo-shadow sign (ultrasound)

The wall-echo-shadow sign (also known as WES sign) is an ultrasonographic finding within the gallbladder fossa referring to the appearance of a "wall-echo-shadow": a curvilinear hyperechogenic line representing the gallbladder wall a thin hypoechoic space representing a small amount of bile a...

Triangular cord sign (biliary atresia)

The triangular cord sign is a triangular or tubular echogenic cord of fibrous tissue, representing the ductal remnant of the extrahepatic bile duct, seen in the porta hepatis at ultrasonography, and is relatively specific for the diagnosis of biliary atresia 1,2. This sign is useful in the eval...

Bunch of grapes sign (disambiguation)

Bunch of grapes sign refers to the imaging appearance of multiple cystic spaces or lesions and it has been described for multiple pathologies: bunches of grapes sign (hepatic abscess) 8 bunch of grapes sign (botryoid rhabdomyosarcoma) 5 bunch of grapes sign (bronchiectasis) 3 bunch of grapes...

Bright dot sign (atypical liver hemangioma)

The bright dot sign refers to the presence of a bright dot within a lesion which remains hypoattenuating on arterial and portal venous phase CT, corresponding to early nodular enhancement seen on dynamic MRI of liver hemangioma. This can be used as an indicator that the lesion in question is a...

Sonographic halo sign

Sonographic halo sign is used in a number of situations. They include: hypoechoic halo sign (also known as target or bull's eye sign) in liver metastases: used in hepatobiliary imaging, is a concerning feature for malignant lesion if the lesion is a hyperechoic liver lesion 1,2 ultrasound halo...

Mickey Mouse sign (disambiguation)

In medical imaging, a Mickey Mouse sign or appearance has been given to imaging features that mimic Mickey Mouse when viewed from the front. It has been described in the following: anencephaly 2 progressive supranuclear palsy 1 synonymously with a finger in glove sign the flared shape of the...

Periportal halo (CT/US)

Periportal halo or periportal collar sign refers to a zone of low attenuation seen around the intrahepatic portal veins on contrast-enhanced CT or hypoechogenicity on liver ultrasound. It likely represents periportal edema, which is often used as a synonymous term. Periportal haloes may occur ar...

Wheel within a wheel sign (hepatic candidiasis)

The wheel within a wheel sign describes one of several possible ultrasound findings of hepatic candidiasis. The finding consists of a round lesion with three layers corresponding to the following histopathological changes 2: peripheral hypoechoic area (fibrosis) middle hyperechoic area (inflam...

Double duct sign

The double duct sign refers to the presence of simultaneous dilatation of the common bile and pancreatic ducts. Being an anatomical sign it can be seen on all modalities that can visualize the region, including: MRI, CT, ultrasound and endoscopic retrograde cholangiopancreatography (ERCP). In ge...

Porcelain gallbladder

Porcelain gallbladder refers to extensive calcium encrustation of the gallbladder wall. The term has been used to emphasize the blue discolouration and brittle consistency of the gallbladder wall at surgery but is often an incidental finding on multiple different imaging modalities. Clinical p...

Rosary sign (gallbladder)

The rosary sign is a CT finding in adenomyomatosis of the gallbladder. It is formed by the enhanced proliferative mucosal epithelium, with the intramural diverticula surrounded by the unenhanced hypertrophied muscle coat of the gallbladder. The rosary sign is similar to the pearl necklace sign.

Saber sign (pneumobilia)

The saber sign refers to a pattern of gas distribution seen in supine abdominal radiographs of patients with pneumobilia. A sword-shaped lucency is apparent in the right paraspinal region of the upper abdomen representing arching gas extending from the common bile duct into the left hepatic duc...

Seurat spleen

Seurat spleen is an angiographic appearance seen following blunt trauma to the spleen. Multiple small punctate regions of intraparenchymal contrast extravasation lead to a spotted appearance. Pathology Several mechanisms are thought to to attribute to this appearance which include sinusoidal s...

Pseudocalculus sign (common bile duct)

The pseudocalculus sign is a term coined to describe a mimic of a distally impacted common bile duct (CBD) stone on ERCP, MRCP and the various forms of cholangiography, including T-tube, CT, intraoperative, and percutaneous 1. It results from the forceful contraction of the choledochal sphincte...

Target sign (choledocholithiasis)

The target sign of choledocholithiasis is a finding seen on contrast-enhanced CT and comprises: central density within the bile duct: stone surrounding low density: bile or mucosa

Pearl necklace sign

The pearl necklace sign occurs in adenomyomatosis of the gallbladder, on both oral cholecystograms and MRCP. It represents the contrast/fluid-filled intramural mucosal diverticula (Rokitansky-Aschoff sinuses); lined up, these are reminiscent of pearls on a necklace. It is synonymous with the CT ...

Cottage loaf sign (liver)

The cottage loaf sign occurs as a result of a right-sided diaphragmatic rupture with partial herniation of the liver through the diaphragmatic defect. The herniated component is separated by a waist at the diaphragm from the larger intra-abdominal component. This shape is reminiscent of a cottag...

Rigler triad (gallstone ileus)

Rigler triad consists of three findings seen in gallstone ileus: pneumobilia small bowel obstruction ectopic calcified gallstone, usually in the right iliac fossa History and etymology It is named after Leo George Rigler, American radiologist (1896-1979) 1. Practical points Rigler triad s...

Caput medusae sign - developmental venous anomalies

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 M...

Water-lily sign (hydatid cyst)

The water-lily sign, also known as the camalote sign, is seen in hydatid infections when there is detachment of the endocyst membrane which results in floating membranes within the pericyst that mimic the appearance of a water lily. It is classically described on plain radiographs (mainly chest...

Strawberry gallbladder

Strawberry gallbladder refers to the surface appearance (not shape) of the mucosa of the gallbladder due to multiple small collections of triglycerides and cholesterol esters within the lamina propria of the gallbladder wall (gallbladder wall cholesterolosis). Strawberry gallbladder represents...

Phrygian cap

Phrygian caps are the most common congenital anatomic variant of the gallbladder. It denotes folding of the fundus back upon the gallbladder body and is asymptomatic with no pathological significance. Radiographic findings A Phrygian cap may be identified on ultrasound, multiphase CT/MRI, or c...

Nutmeg liver

A nutmeg liver appearance is due to a perfusion abnormality of the liver usually as result of hepatic venous congestion. When hepatic veins are congested, contrast is prevented from diffusing through the liver in a normal manner. This results in a mottled pattern of contrast enhancement in the a...

Mercedes-Benz sign (gallbladder)

In the gallbladder, the Mercedes-Benz sign describes a star-shaped pattern of gas-fissuring within gallstones initially described on an abdominal radiograph 2. Fissures, usually fluid-filled, are present in close to 50% of gallstones. Less than half of these fissured gallstones contain some amo...

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