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.

631 results found
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Percutaneous liver tumor ablation

Percutaneous liver tumor ablation techniques are well-established and effective therapeutic alternatives for the treatment of primary and secondary liver tumors. Hepatocellular carcinoma (HCC) and colorectal oligometastatic disease are the most common indications. There are specific indications ...
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Percutaneous transhepatic biliary drainage

Percutaneous transhepatic biliary drainage, also known as percutaneous transhepatic cholangial drainage (PTCD), is an interventional radiology procedure undertaken for those with biliary obstruction.  It is almost exclusively performed in those with a malignant obstruction, such as cholangiocar...
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Percutaneous transhepatic cholangiography

Percutaneous transhepatic cholangiography (PTC) is a radiographic technique employed in the visualization of the biliary tree and can be used as the first step in a number of percutaneous biliary interventions (e.g. percutaneous transhepatic biliary stent placement) Indications Purely diagnost...
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Periampullary diverticulum

A periampullary diverticulum is a location-specific type of duodenal diverticulum.  Epidemiology The incidence is reported to increase with age with reported rates as high as 27%. Pathology It is located close to the region of the duodenum often involving the D2 segment.  Associations can ...
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Periampullary tumors

Periampullary tumors are those that arise within 2 cm of the ampulla of Vater in the duodenum. Tumors that fall under this group include four main types of tumors 1,4 that will be approached in their specific articles: pancreatic head/uncinate process tumors: includes pancreatic ductal adenoca...
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Peribiliary cyst

Peribiliary cysts occur in the setting of chronic liver disease where it is a rare, benign, and often asymptomatic disorder. They consist of cystic formations around the intrahepatic biliary ducts, primarily in a hilar distribution. Unlike choledochal cysts (for example in Caroli disease), perib...
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Perihilar cholangiocarcinoma (staging)

Perihilar cholangiocarcinoma staging is, for prognostication, most commonly conducted using the TNM staging classification of the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC). As of 2018, the staging criteria are in their 8th edition and reflected below...
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Peripancreatic pseudoaneurysm

Peripancreatic pseudoaneurysm refers to the formation of a pseudoaneurysm around the pancreatic gland. It is a rare but potentially lethal complication 5. Epidemiology Formation of pseudoaneurysm can occur in as many as 10% of cases of pancreatitis. The time interval is variable, ranging from ...
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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...
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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...
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Periportal hyperechogenicity

Periportal hyperechogenicity can result from many causes including: pneumobilia cholecystitis schistosomiasis of the portal region recurrent pyogenic cholangitis (oriental) inflammatory bowel disease: has been described to give "echo-rich" periportal cuffing 2​
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Periportal hypoechogenicity

Periportal hypoechogenicity can result from many causes: orthotopic liver transplant rejection congestive hepatopathy malignant lymphatic obstruction cholangitis viral hepatitis See also periportal hyperechogenicity periportal halo
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Peritoneal hydatidosis

Peritoneal hydatidosis occurs secondary to seeding of echinococcosis to the peritoneum, usually secondary to rupture of hydatid disease of liver. Pathology Seeding involves the entire peritoneum and gives appearance of a multiloculated mass.  Classification Peritoneal hydatidosis can be prim...
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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 ch...
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Pleuro-biliary fistula

Pleuro-biliary fistulae refer to abnormal fistulous communications between the biliary tree and pleural space. It forms the large portion of thoraco-biliary fistulas and can occur in various situations such as with complications secondary to trauma, infection, malignancy, biliary disease, or per...
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Pneumobilia

Pneumobilia, also known as aerobilia, is the accumulation of gas in the biliary tree. It is important to distinguish pneumobilia from portal venous gas, the other type of branching hepatic gas. There are many causes of pneumobilia and clinical context is often important to distinguish between th...
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Pneumobilia vs portal venous gas (mnemonic)

Pneumobilia and portal venous gas are two causes of an intrahepatic branching gas pattern. The two have different causes and implications and need to be distinguished on imaging, and a simple mnemonic can help. Mnemonic A simple mnemonic for remembering the difference in appearance is: portal...
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Point-of-care ultrasound (curriculum)

The point-of-care ultrasound (PoCUS) curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core applications of ultrasonography in a point-of-care setting. Point-of-care ultrasound refers to ultrasonography which may be simultaneously performed,...
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Polyarteritis nodosa

Polyarteritis nodosa (PAN) is a systemic inflammatory necrotizing vasculitis that involves small to medium-sized arteries (larger than arterioles).  Epidemiology PAN is more common in males and typically presents around the 5th to 7th decades. 20-30% of patients are hepatitis B antigen positiv...
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Polycystic liver disease

Polycystic liver disease (PCLD) is a hereditary condition that may arise either in patients with autosomal dominant polycystic kidney disease (ADPKD) or in patients with a different genetic mutation that results solely in autosomal dominant polycystic liver disease. Clinical presentation Most ...
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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...
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Porta hepatis

The porta hepatis is a deep fissure in the inferior surface of the liver through which all the neurovascular structures (except hepatic veins) and hepatic ducts enter or leave the liver 1. It runs in the hepatoduodenal ligament and contains: right and left hepatic ducts right and left branches...
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Portal biliopathy

Portal biliopathy or portal ductopathy refers to biliary obstruction that is associated with cavernous transformation of the portal vein due to portal vein thrombosis 1,2. Clinical presentation Portal biliopathy may present as jaundice, cholangitis due to bile duct obstruction, or rarely as he...
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Portal hypertension

Portal hypertension is defined as hepatic venous pressure gradient (HVPG) greater than 5 mmHg. HVPG is a surrogate for the portosystemic pressure gradient. Clinically significant portal hypertension is defined as a gradient greater than 10 mmHg and variceal bleeding may occur at a gradient great...
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Portal hypertensive gastropathy / enteropathy / colopathy

In portal hypertension, chronic portal venous congestion leads to dilatation and ectasia of the submucosal vessels in the stomach (portal hypertensive gastropathy), small bowel (portal hypertensive enteropathy) and/or large bowel (portal hypertensive colopathy). This may result in upper or lower...
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Portal vein

The portal vein (PV) (sometimes referred to as the main or hepatic portal vein) is the main vessel in the portal venous system and drains blood from the gastrointestinal tract and spleen to the liver. Gross anatomy The portal vein usually measures approximately 8 cm in length in adults with a ...
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Portal vein embolization

Portal vein embolization (PVE) is a technique used to selectively occlude the blood supply to one of the liver lobes, diverting portal blood flow to the other lobe, the future liver remnant (FLR). This diversion will increase the size of the post-hepatectomy future liver remnant, which improves...
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Portal vein thrombosis

Portal vein thrombosis may be seen in a variety of clinical contexts, and when acute can be a life-threatening condition. It is a major cause of non-cirrhotic presinusoidal portal hypertension. Portal vein thrombus may be either bland and/or malignant (i.e. tumor thrombus), and it is a critical ...
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Portal venous gas

Portal venous gas is the accumulation of gas in the portal vein and its branches. It needs to be distinguished from pneumobilia, although this is usually not too problematic when associated findings are taken into account along with the pattern of gas (i.e. peripheral in portal venous gas, centr...
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Portal venous varix

A portal venous varix (plural: portal venous varices) refers to a segments of aneurysmal / variceal dilatation of the portal vein are extremely rare and represent only 3% of all aneurysms of the venous system. They are still however the most common visceral varix 8. Clinical presentation Most ...
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Portopulmonary hypertension

Portopulmonary hypertension (POPH/PPHTN) refers to pulmonary artery hypertension that develops in the setting of portal hypertension (with or without underlying liver disease). It falls under group 1.4 of the Dana point 2008 pulmonary hypertension classification system. Epidemiology The preval...
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Portosystemic collateral pathways

Portosystemic collateral pathways (also called varices) develop spontaneously via dilatation of pre-existing anastomoses between the portal and systemic venous systems. This facilitates shunting of blood away from the liver into the systemic venous system in portal hypertension, as a means for r...
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Posterior parahepatic cyst

Posterior parahepatic cysts are an incidental finding of a small, isolated, nodular structure adjacent to the posterior segment of the right hepatic lobe.  Pathology Due to the benign imaging characteristics and stability on long-term imaging, no pathologic diagnosis of these lesions has been ...
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Posterior right subhepatic space

The posterior right subhepatic space (also known as the hepatorenal fossa or Morison pouch) separates the liver from the right kidney. It is a potential space that is not filled with any fluid in normal conditions. Gross anatomy The posterior right subhepatic space is a subcompartment of the s...
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Posttransplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD), also referred as post-transplant lymphoproliferation disorder, represents a variety of conditions ranging from lymphoid hyperplasia to malignancy, included in the WHO classification of tumors of hematopoietic and lymphoid tissues. It can be a ...
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Primary biliary cholangitis

Primary biliary cholangitis (PBC) is a chronic progressive cholestatic liver disease that is the cause of 1-2% of deaths from cirrhosis and constitutes the third most common indication for liver transplantation in adults. Terminology The name of this disease was changed from primary biliary ci...
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Primary effusion lymphoma

Primary effusion lymphoma is a rare form of non-Hodgkin lymphoma (diffuse large cell B cell lymphoma) characterized by malignant fluid accumulation in the absence of lymphadenopathy. Typical sites of accumulation include pleural space pericardium peritoneal space Associations immunodeficie...
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Primary hepatic lymphoma

Primary hepatic lymphoma (PHL) is rare, with roughly 100 described cases. If it is being considered as a diagnosis, distal lymphadenopathy, splenomegaly, bone marrow disease, and leukemia should not be present for at least 6 months after the liver tumor is detected (see: secondary hepatic lympho...
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Primary hyperoxaluria

Primary hyperoxaluria, also referred as primary oxalosis, is a congenital autosomal recessive disease related to a liver enzyme deficiency leading to massive cortical nephrocalcinosis and renal failure.  Please, refer on secondary oxalosis for a discussion on the acquired form of hyperoxaluria....
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Primary myelofibrosis

Primary myelofibrosis is a myeloproliferative neoplasm in which there is the replacement of bone marrow with collagenous connective tissue and progressive fibrosis. It is characterized by: extramedullary hematopoiesis progressive splenomegaly anemia variable change in the number of granulocy...
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Primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is an uncommon inflammatory condition, which affects the biliary tree resulting in multiple strictures, liver damage, and eventually cirrhosis. The diagnosis can be made when there are classical imaging features in the correct clinical context, and secondary...
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Prolonged heterogeneous liver enhancement (CEUS)

Prolonged heterogeneous liver enhancement (PHLE), also informally termed as the "disappearing liver" phenomenon, is a very rare, benign complication of ultrasound contrast media, of currently unknown etiology 1. PHLE manifests itself as confluent, rapidly appearing hyperechoic foci in the liver,...
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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...
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Pseudocirrhosis

Pseudocirrhosis is a radiological term used to convey the imaging findings of cirrhosis, but emphasize that it occurs in the setting of hepatic metastases. It is most commonly reported following chemotherapeutic treatment of breast cancer metastases, although has also been reported before treatm...
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Pseudocyst

A pseudocyst is an abnormal fluid-filled cavity which is not lined by epithelium.  It is this fact that distinguishes it pathologically from a cyst, which is lined by epithelium. Examples of pseudocysts include: adrenal pseudocyst auricular pseudocyst meconium pseudocyst pancreatic pseudocy...
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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...
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Pseudolipoma of the Glisson capsule

Pseudolipoma of the Glisson capsule is an uncommon developmental anomaly in which a piece of colonic epiploic fat becomes ectopically located within the liver capsule. Radiographic features CT well-circumscribed fat attenuation (-20 to -70 HU) nodule at the liver surface it can sometimes hav...
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Pseudopancreatitis

Pseudopancreatitis refers to the presence of fluid in or around the pancreas in the setting of trauma but in the absence of direct signs of traumatic pancreatic injury. Most patients will have a normal serum lipase level, but amylase has a limited sensitivity and specificity for pancreatic traum...
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Puestow procedure

The Puestow procedure or lateral pancreaticojejunostomy is a lateral side-to-side pancreaticojejunostomy that is used for the treatment of chronic pancreatitis. The pancreas is essentially filleted along its long axis from the uncinate process to the tail and connected to a Roux en-Y loop of je...
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Pulsatile portal venous flow

A pulsatile portal venous flow pattern can result from both physiological and pathological causes. In well subjects mild pulsatility, or in rare situations, even marked pulsatility has been described, particularly in thin subjects, with a venous pulsatility index of >0.5 with an inverse correla...
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Pylephlebitis

Pylephlebitis, also known as ascending septic thrombophlebitis, is a thrombotic occlusion of the portal vein or its branches secondary to infection in regions that drain to the portal venous system. Clinical Presentation Clinical presentation is often vague. Patients may initially present with...
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Radiation-induced liver disease

Radiation-induced liver disease (RILD), also referred to as radiation hepatitis, represents the toxic effect of radiation therapy on normal hepatocytes.   This article will discuss liver toxicity appearances after external beam radiotherapy techniques. Please refer to the dedicated article on s...
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Radioembolization

Radioembolization is the delivery of radioactive microspheres to cancers using an endovascular approach. It is often performed as an outpatient procedure.  Indications hepatocellular carcinoma hepatic metastases from colorectal carcinoma Contraindications Absolute contraindications excessi...
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Recurrent pyogenic cholangiohepatitis

Recurrent pyogenic cholangiohepatitis, previously known as oriental cholangiohepatitis, is a condition most commonly found in patients residing in or immigrated from Southeast Asia and is characterized by intra and extrahepatic bile duct strictures and dilatation with an intraductal pigmented st...
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Regenerative liver nodule

Regenerative liver nodules are a form of non-neoplastic nodules that arise in a cirrhotic liver. Terminology This may be slightly different from the term nodular regenerative hyperplasia, which are described histopathologically as regenerative nodules with little or no hepatic fibrosis and lar...
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Retained gallstone

Retained gallstones, also called dropped or slipped gallstones, are common during a laparoscopic cholecystectomy, with a reported incidence of 0.1–20%, and occur when gallstones are inadvertently spilled into the peritoneal cavity. Clinical presentation Many cases of dropped gallstones will be...
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Reticuloendothelial system

The reticuloendothelial system (RES) comprises a number of tissues: spleen bone marrow liver Kupffer cells
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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 metastases.
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Revised Atlanta classification of acute pancreatitis

The Revised Atlanta classification of acute pancreatitis from 2012 is an international multidisciplinary classification of the severity of acute pancreatitis, updating the 1992 Atlanta classification. The worldwide consensus aims for an internationally agreed-upon classification of acute pancre...
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Rhabdomyosarcomas (biliary tract)

Rhabdomyosarcomas of the biliary tract are rare tumors, usually identified in children, with a very poor prognosis. They are usually grouped under botryoid rhabdomyosarcomas. For a general discussion of this type of tumor, please refer to the article on rhabdomyosarcomas. Epidemiology Rhabdom...
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Riedel lobe

Riedel lobe is a common anatomical variant of the liver to be aware of because it can simulate a mass. Its misidentification as a pathologic abdominal mass has led to surgery. Pathology can also occur within it (e.g. malignancy or even torsion) and cause atypical hepatic symptoms low in the pelv...
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Right hepatic artery

The right hepatic artery (RHA) is formed when the proper hepatic artery (PHA) bifurcates. The hepatic arteries provide 25% of the blood supply and 50% of the oxygen supply to the liver. Gross anatomy The proper hepatic artery bifurcates into the right and left hepatic arteries at or before rea...
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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...
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Right subphrenic space

The right subphrenic space (a.k.a. right anterior space, right subdiaphragmatic space) is a potential space that lies between the right lobe of the liver and the inferior surface of the diaphragm. Gross anatomy This is a subcompartment of the supracolic compartment. It reaches as far as the up...
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Right triangular ligament of the liver

The right triangular ligament is a peritoneal suspensory ligament of the liver. It is formed by the fusion of the superior and inferior reflections of the right coronary ligament. It is longer than the left triangular ligament and compartmentalises the right subphrenic and subhepatic spaces.
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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...
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Rokitansky-Aschoff sinuses

Rokitansky-Aschoff sinuses are diverticula of the gallbladder wall which may be microscopic or macroscopic. Histologically, they are outpouchings of gallbladder mucosa that sit within the gallbladder muscle layer. Related pathology They are not of themselves considered abnormal, but may be ass...
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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...
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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.
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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...
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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...
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Santorinicele

A santorinicele refers to a cystic dilatation of the end of the dorsal pancreatic duct (duct of Santorini) 1,2 and is believed to be analogous to a dilatation of the most distal common bile duct, which is commonly known as a choledochocele 3.  It usually occurs in association with pancreas divi...
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Sarcoidosis (abdominal manifestations)

Sarcoidosis is a systemic inflammatory disease of unknown origin characterized by the formation of non-caseating granulomas. Virtually any organ system may be involved. Although less common than pulmonary and mediastinal disease, abdominal sarcoidosis can mimic more common infectious or neoplast...
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Schistosomiasis

Schistosomiasis (also referred to as bilharzia or snail fever) is the result of infection by blood fluke (trematode worm) of the Schistosoma species. Epidemiology Schistosomiasis is very common, affecting over 200 million people, with the vast majority (85%) in Africa. It is prevalent in tropi...
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Schistosomiasis (hepatic manifestations)

Schistosomiasis hepatic manifestations are a chronic result of the deposition of eggs into small portal venules leading to periportal fibrosis and liver cirrhosis.   For a general view over this trematode infection, please refer to the main article on schistosomiasis. Epidemiology Association...
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Scleroderma

Scleroderma, also known as systemic sclerosis, is an autoimmune connective tissue disorder characterized by multisystem fibrosis and soft tissue calcification. As such, it affects many separate organ systems, which are discussed separately: musculoskeletal manifestations of scleroderma pulmona...
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Scleroderma (hepatobiliary manifestations)

Hepatobiliary manifestations of scleroderma are only present symptomatically in a minority of patients. Around 2.5% of patients with scleroderma develop clinically significant primary biliary cholangitis, however, antibody studies suggest that subclinical disease may be present in as many as 15%...
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Sclerosing cholangitis

There are three forms of sclerosing cholangitis: primary sclerosing cholangitis IgG4-related sclerosing cholangitis secondary sclerosing cholangitis
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Secondary hepatic involvement with lymphoma

Secondary hepatic involvement with lymphoma (secondary hepatic lymphoma) is common, much more so than primary hepatic lymphoma.  Clinical presentation Hepatomegaly with deranged liver function tests is the most common presentation. Jaundice is common. Rarely, patients may present with acute li...
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Secondary sclerosing cholangitis

Secondary sclerosing cholangitis refers to manifestations of sclerosing cholangitis that resemble primary sclerosing cholangitis but can be attributed to known insults to the biliary tree. Pathology Secondary sclerosing cholangitis is a chronic cholestatic disease. The entity is characterized ...
Article

Selective internal radiation therapy

Selective internal radiation therapy (SIRT), also known as hepatic radioembolization, is a relatively new and developing modality for treating non-resectable liver tumors. The procedure consists of a transcatheter injection of radioactive particles via the hepatic artery.  It is generally consi...
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Selenium toxicity

Selenium toxicity (rarely: hyperselenemia) is caused by excessive intake of the non-metallic element selenium (Se) in the diet. Epidemiology It is less common than selenium deficiency. It is most frequently seen in some parts of India, in which there are naturally high levels of selenium in th...
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Septate gallbladder

Septate gallbladder is a congenital variant where there may be a single septum or multiple septa in the gallbladder splitting its lumen into several parts. There can be communication between the separated parts of gallbladder through small pores. The condition is mostly asymptomatic and incident...
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Serous cystadenoma of pancreas

Serous cystadenoma of the pancreas, also referred as microcystic adenoma, is an uncommon type of benign cystic pancreatic neoplasm.  Epidemiology There is a recognized strong female predilection (M:F ~ 1:4) and usually presents in middle age to elderly patients (>60 years of age).  Clinical p...
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Serpent sign

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

Serum ascites albumin gradient

The serum–ascites albumin gradient (SAAG) is the difference between the concurrently obtained serum albumin concentration and the albumin concentration of the ascitic fluid obtained during paracentesis.  Pathology A difference ≥1.1 grams/deciliter (g/dL) indicates portal hypertension as the li...
Article

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...
Article

Sickle cell disease

Sickle cell disease (SCD) (historically known as drepanocytosis) is a hereditary (autosomal recessive) condition resulting in the formation of abnormal hemoglobin (a hemoglobinopathy), which manifests as multisystem ischemia and infarction, as well as hemolytic anemia.  Hemoglobin SC (HbSC) dis...
Article

Sickle cell disease (abdominal manifestations)

Abdominal manifestations of sickle cell disease (SCD) are wide and can involve many organs. For a general discussion, please refer to sickle cell disease. Splenic splenomegaly may occur transiently with the sequestration syndrome, where rapid pooling of blood occurs in the spleen, resulting ...
Article

Simple hepatic cyst

Simple hepatic cysts are common benign liver lesions and have no malignant potential. They can be diagnosed with ultrasound, CT, or MRI. Epidemiology Simple hepatic cysts are one of the commonest liver lesions, occurring in ~2-7% of the population 1,2. There may be a slight female predilection...
Article

Sinistral portal hypertension

Sinistral portal hypertension (also known as left-sided portal hypertension or segmental portal hypertension) is an uncommon form of portal hypertension. Clinical presentation Sinistral portal hypertension is most commonly found incidentally in asymptomatic patients. In symptomatic patients, t...
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Sinusoidal obstruction syndrome

Sinusoidal obstruction syndrome (SOS), previously known as hepatic veno-occlusive disease (VOD), is a condition arising from occlusion of hepatic venules. Clinical presentation right upper quadrant pain painful hepatomegaly ascites abnormal liver function tests Pathology Toxic injury to l...
Article

Situs inversus

Situs inversus, (rare plural: sitūs inversi) short form of the Latin “situs inversus viscerum”, is a term used to describe the inverted position of chest and abdominal organs. It is called situs inversus totalis when there is a total transposition of abdominal and thoracic viscera (mirror image ...

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