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Inferior pancreaticoduodenal artery

The inferior pancreaticoduodenal artery is the first branch of the superior mesenteric artery (SMA). It usually arises at the inferior border of the pancreas or with the first jejunal artery as part of the pancreaticoduodenojejunal trunk. It anastomoses with branches of the superior pancreati...

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...

Pancreatic trauma

The pancreas is uncommonly injured in blunt trauma. However, pancreatic trauma has a high morbidity and mortality rate. Epidemiology The pancreas is injured in ~7.5% (range 2-13%) of blunt trauma cases 1,3,7. Motor vehicle accidents account for the vast majority of cases. Penetrating trauma co...

Focused Assessment with Sonography for Trauma (FAST) scan

Focused Assessment with Sonography for Trauma (FAST) scan is a point-of-care ultrasound (POCUS) examination performed at the time of presentation of a trauma patient. It is invariably performed by a clinician, who should be formally trained, and is considered as an 'extension' of the trauma cl...

Liver trauma

The liver is one of the most frequently damaged organs in blunt trauma, and liver trauma is associated with a significant mortality rate. Epidemiology In blunt abdominal trauma, the liver is injured ~5% (range 1-10%) of the time 1,3. Clinical presentation Patients can present with right uppe...

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...

Gallbladder volvulus

Gallbladder volvulus is a relatively rare condition in which there is a rotation of the gallbladder around the axis of the cystic duct and artery. Clinical presentation Symptoms are non-specific, however right upper quadrant pain and vomiting are similar to biliary colic. Laboratory evaluation...

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 ...

2001 WHO classification of hepatic hydatid cysts

The 2001 World Health Organizatiοn (WHO) classification of hepatic hydatid cysts is used to assess the stage of hepatic hydatid cysts on ultrasound and is useful in deciding the appropriate management depending on the stage of the cyst. This classification was proposed by the WHO in 2001 and, at...

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 ...

Ciliated hepatic foregut cyst

Ciliated hepatic foregut cysts are a very rare type of hepatic cyst, with non-specific radiological features. They are usually benign, but rare cases of malignant degeneration (to squamous cell carcinoma) have also been reported. Epidemiology They are more often seen in adults, although a few...

Hepatisation of the gallbladder

Hepatisation of the gallbladder is a sonographic entity in which the gallbladder lumen is entirely filled with tumefactive sludge giving the gallbladder a similar appearance to liver parenchyma. It is one of the causes of non-visualization of the gallbladder on sonography. Pathology In the set...

Exophytic hepatic mass

Exophytic hepatic mass or tumor is a lesion which predominantly lies outside the margins of liver but originates from within the liver. Pathology Causes include 1: benign hepatic hemangioma hepatic adenoma hepatic cyst hepatic angiomyolipoma focal nodular hyperplasia malignant hepati...

Flash filling hepatic hemangioma

Flash filling hepatic hemangiomas, also known as flash filling hepatic venous malformations, are a type of atypical hepatic hemangioma, which due to its imaging features often raises the concern of a malignant process rather than a benign one. Terminology It is important to note that accordin...

Ansa pancreatica

The ansa pancreatica is a rare type of anatomical variation of the pancreatic duct. It is a communication between the main pancreatic duct (of Wirsung) and the accessory pancreatic duct (of Santorini). Recently, the ansa pancreatica has been considered as a predisposing factor in patients with i...

Meandering main pancreatic duct

Meandering main pancreatic duct (MMPD) denotes a main pancreatic duct that drains normally into the major papilla but performs a hairpin turn (reverse Z-type) or loop (loop-type) in the pancreatic head, in contradistinction to the smooth curvature seen in most cases. These ductal variants are f...

Gangrenous cholecystitis

Gangrenous cholecystitis is the most common complication of acute cholecystitis, affecting ~15% (range 2-30%) of patients. Epidemiology Risk factors male increasing age delayed surgery cardiovascular disease diabetes mellitus systemic inflammatory response syndrome 5 Pathology Gangren...

Sphincter of Oddi

The sphincter of Oddi (also known as the sphincter of ampulla or choledochal sphincter) is a complex of four smooth muscle sphincters within the duodenal wall. It surrounds, and helps fix to the duodenum, the duct of Wirsung, common bile duct and the ampulla of Vater 1,2. When relaxed it allow...

5-F risk factors for cholelithiasis (mnemonic)

The 5-F rule refers to risk factors for the development of cholelithiasis in the event of upper abdominal pain: fair: more prevalent in the Caucasian population 1 fat: BMI >30 kg/m2 and hyperlipidemia 3,4 female fertile: one or more children forty: age ≥40 years cholelithiasis can occur in...

Hepatic infarction

Hepatic infarction is an extremely rare situation because the liver has a dual blood supply from the hepatic artery and portal vein. Hepatic infarction can occur when there is both hepatic arterial and portal vein flow compromise but most cases are due to acute portal venous flow compromise 11. ...

Common bile duct

The common bile duct (CBD), which is sometimes simply known as the bile duct, is formed by the union of the cystic duct and common hepatic duct (CHD). Terminology In ultrasound imaging, it is not always possible to confidently see where the cystic duct enters the common hepatic duct to form t...

Ligamentum venosum

The ligamentum venosum is a fibrous remnant which travels superiorly from the porta hepatis of the liver to the inferior vena cava. It is often obliterated in adults. In the fetus, it is patent and known as the ductus venosus which shunts blood returning from the placenta in the umbilical vein...

Pancreatic duct diameter

The diameter of the (main) pancreatic duct is a commonly assessed parameter in imaging. Gross anatomy The duct diameter is greatest at the head and neck region and is slightly narrower towards the body and tail. Its normal reported value ranges between 1-3.5 mm in <50 year old and 2-5 mm in 70...

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...

Congestive hepatopathy

Congestive hepatopathy includes a spectrum of hepatic derangements that can occur in the setting of right-sided heart failure (and its underlying causes). If there is subsequent hepatic fibrosis the term cardiac cirrhosis may be used. The condition can rarely occur as a result of non-cardiac cau...

Chronic cholecystitis

Chronic cholecystitis refers to prolonged inflammatory condition that affects the gallbladder. It is almost always seen in the setting of cholelithiasis (95%), caused by intermittent obstruction of the cystic duct or infundibulum, or dysmotility. Clinical presentation Patients may have a histo...

Pepper syndrome

Pepper syndrome is a term not readily used in day-to-day practice and usually refers to primary adrenal neuroblastoma with extensive liver metastases 1. In essence, it refers to stage 4S neuroblastoma (see staging of neuroblastoma). Cohen syndrome, a genetic disorder, is sometimes referred to a...

Pediatric liver tumor staging (PRETEXT grouping system)

The PRETEXT system proposed by the International Childhood Liver Tumors Strategy Group (previously called Société Internationale d’Oncologie Pédiatrique - Epithelial Liver Tumor Study Group - SIOPEL) aims for staging and risk stratification of liver tumors at diagnosis. It is used to describe ...

Hepatic amyloidosis

Hepatic amyloidosis refers to the extracellular deposition of amyloid in the parenchyma sinusoids or vessel walls. Liver involvement in amyloidosis is uncommon. Pathology It can be primary or secondary and it typically occurs as diffuse infiltration 2. There is amyloid deposition in liver p...

Choledochocele

Choledochoceles refer to a specific type of choledochal cyst (type III under the Todani classification system). In this type, there is dilatation of the intramural portion of the distal common bile duct within the duodenal wall. Its precise etiology is not clear 3. Patients are usually adolescen...

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 Caput is the Latin for head, ...

Hepatic lipoma

Hepatic lipomas are uncommon benign lesions of the liver. Epidemiology Associations tuberous sclerosis renal angiomyolipoma Pathology As with lipomas elsewhere in the body, hepatic lipomas are marginated masses that are composed of mature adipocytes without evidence of cellular atypia. Hi...

Hepatic adrenal rest tumor

Hepatic adrenal rest tumors (HART), previously been termed primary hypernephroma of the liver or hypernephroid carcinoma of the liver, are very rare liver tumors with histology similar to adrenocortical carcinoma. Epidemiology It tends to occur in younger patients and there is no recognized g...

Hepatic lymphangioma

Hepatic lymphangiomas are a rare benign condition that corresponds to focally dilated lymphatic channels in the liver. For a general discussion on this topic, please refer to the parental article on lymphatic malformations. Clinical presentation Most cases are asymptomatic. Pathology A ly...

Sonographic Murphy sign

Sonographic Murphy sign is defined as maximal abdominal tenderness from the 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 im...

CT severity index in acute pancreatitis

The CT severity index (CTSI) is based on findings from an enhanced CT scan to assess the severity of acute pancreatitis. The severity of acute pancreatitis CT findings has been found to correlate well with clinical indices of severity. The CT severity index sums two scores: Balthazar score: g...

Balthazar score

The Balthazar score is a subscore within the CT severity index (CTSI) for grading of acute pancreatitis. The CTSI sums two scores: Balthazar score: grading of pancreatitis (A-E) grading the extent of pancreatic necrosis The Balthazar score was originally used alone, but the addition of a sc...

Portal venous varix

A portal venous varix (plural: portal venous varices) refers to a segments of aneurysmal or variceal dilatation of the portal vein. Epidemiology Portal venous varices are extremely rare, representing only 3% of all aneurysms of the venous system. They are still, however, the most common viscer...

Wandering spleen

Wandering spleen is a rare condition in which the spleen migrates from its usual anatomical position, commonly to the lower abdomen or pelvis. Epidemiology Wandering spleen is rare, with a reported incidence of <0.5%. Diagnosis is most commonly made between the ages of 20-40 years and is more...

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 ...

Gallbladder duplication

Gallbladder duplication is a rare anatomic anomaly characterized by the presence of an accessory gallbladder. There is no increased risk of malignancy or calculi compared to a single gallbladder. Epidemiology Prevalence is estimated at 1 in 4000 live births 3. Pathology Classification Boyd...

Passive hepatic congestion

Passive hepatic congestion, also known as congested liver in cardiac disease, describes the stasis of blood in the hepatic parenchyma, due to impaired hepatic venous drainage, which leads to the dilation of central hepatic veins and hepatomegaly. Passive hepatic congestion is a well-studied re...

Accessory gallbladder

Accessory gallbladders are a rare anatomical variant occurring in 0.03% of cases (approximately 1 in 3000 people). They can arise from either the left or right hepatic ducts or both. Accessory gallbladders arise from a bifid diverticulum of the hepatic duct in the 5th or 6th week of development ...

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...

Liver and biliary interventional procedures

There is a wide range of liver and biliary interventional procedures, both diagnostic and therapeutic, most commonly using CT-guidance or ultrasound-guidance. Vascular Interventions: transjugular intrahepatic portosystemic shunt (TIPS) transjugular liver biopsy (TJLB) Percutaneous...

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 bi...

Hepatobiliary MRI contrast agents

Hepatobiliary MRI contrast agents are specialized contrast agents used to aid diagnosis in MRI. They are separated into three categories: gadolinium-based agents, manganese-based agents and superparamagnetic iron oxide particles. Gadolinium-based agents Gadolinium (Gd) based contrast agents ...

Splenic hydatid infection

Splenic hydatid infection is a rare form of hydatid disease, and isolated splenic involvement is even less common. For a general discussion, and for links to other system-specific manifestations, please refer to the article on hydatid disease. Epidemiology Splenic hydatid disease has been re...

Hepatic encephalopathy

Hepatic encephalopathy, also known as acute hyperammonemic encephalopathy or portosystemic encephalopathy, refers to a spectrum of neuropsychiatric abnormalities occurring in patients with liver dysfunction and portal hypertension. It results from exposure of the brain to excessive amounts of am...

Gallbladder sludge

Gallbladder sludge, also known as biliary sand, biliary sediment, or thick bile, is a mixture of particulate matter and bile, normally seen as a fluid-fluid level in the gallbladder on ultrasound, corresponding to the precipitate of bile solutes. Terminology The term biliary microlithiasis is...

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...

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...

Hepatic haemangiomatosis

Hepatic haemangiomatosis is a condition in which there are multiple hemangiomas affecting the liver. Terminology When the lesions are spread throughout the liver, then this is termed diffuse hepatic haemangiomatosis. Pathology Associations giant liver hemangioma 2 Radiographic features CT...

Ultrasound-guided biopsy

Ultrasound-guided biopsy is one form of image-guided biopsy, typically performed by a radiologist. It is the most common form of image-guided biopsy, offering convenience and real-time dynamic observation with echogenic markers on cannulae allowing for precise placement. It can potentially be u...

Granulomatous hepatitis

Granulomatous hepatitis refers to an inflammatory liver disease associated with granuloma formation in the liver. These can be caseating or non-caseating. Pathology Associations It can be associated with a wide variety of conditions, which most commonly includes sarcoidosis: hepatic manifest...

Gallstones

Gallstones, also called cholelithiasis, are concretions that may occur anywhere within the biliary system, most commonly within the gallbladder. Terminology Gallstones (cholelithiasis) describe stone formation at any point along the biliary tree. Specific names can be given to gallstones depe...

Biliary cystadenocarcinoma

Biliary cystadenocarcinomas are rare cystic hepatic neoplasms. They can be thought of as a malignant counterpart of biliary cystadenomas. Epidemiology There is recognized increased female predilection. Its incidence peak is around 60 years of age. Clinical presentation The clinical symptoms ...

Hepatofugal

Hepatofugal or non-forward portal flow (NFPF) is an abnormal flow pattern in which the portal venous flow is from the periphery of the liver towards the porta hepatis and backwards along the portal vein. This phenomenon is not uncommon in patients with liver disease 3. It is the opposite of hep...

Gallbladder empyema

Gallbladder empyema (suppurative cholecystitis 1) is an uncommon complication of cholecystitis and refers to a situation where the gallbladder lumen is filled and distended by purulent material (pus). Epidemiology There is an increased incidence in those with diabetes mellitus 2 and/or advance...

Pulsatile portal venous flow

A pulsatile portal venous flow pattern is an abnormal form of portal venous flow and 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 pul...

Splenic hamartoma

Splenic hamartomas are very rare lesions commonly found incidentally on imaging. They are most often solitary but may be present as multiple nodules in patients with tuberous sclerosis or Wiskott-Aldrich syndrome. Terminology The recently-described sclerosing angiomatoid nodular transformatio...

Spontaneous splenorenal shunt

A spontaneous splenorenal shunt (or simply splenorenal shunt) refers to an abnormal collateral portosystemic communication between the splenic vein and the left renal vein. It is one of the features of portal hypertension. See also portosystemic shunts surgical splenorenal shunt

Milan criteria in liver tranplantation

The Milan criteria are a generally accepted set of criteria used to assess suitability in patients for liver transplantation with cirrhosis and hepatocellular carcinoma. In order to be suitable for a liver transplantation, one needs to have 1: single tumor with a diameter of ≤5 cm, or up to 3 ...

Hepatic capsular retraction

Hepatic capsular retraction is an uncommon finding that is defined as loss of the normal liver contour due to focal flattening/irregularity or concavity. It is related to several benign and malignant pathologies. Differential diagnosis The list of differential diagnoses associated with hepatic...

Biliary tree anatomy

A branching ductal system that collects bile from the hepatic parenchyma and transports it to the duodenum constitutes the biliary tree. Gross anatomy By convention the biliary tree is divided into intra- and extra-hepatic bile ducts 1. There is significant variation in the biliary tree with t...

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 ...

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...

Acute acalculous cholecystitis

Acute acalculous cholecystitis refers to the development of cholecystitis in the gallbladder either without gallstones or with gallstones where they are not the contributory factor. It is thought to occur most often due to biliary stasis and/or gallbladder ischemia. Epidemiology Acute acalculo...

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 ...

Pancreas divisum

Pancreas divisum represents a variation in pancreatic ductal anatomy that can be associated with abdominal pain and idiopathic pancreatitis. It is characterized, in the majority of cases, by the dorsal pancreatic duct (i.e. main pancreatic and Santorini ducts) directly entering the minor papilla...

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...

Hepatic hydrothorax

Hepatic hydrothorax is an uncommon manifestation of cirrhosis with ascites. It is one of the pulmonary complications of cirrhosis with portal hypertension. It is characterized by the formation of pleural effusions usually greater than 500 mL in patients with portal hypertension without any oth...

Hepatic epithelioid hemangioendothelioma

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare, low- to intermediate-grade malignant hepatic vascular tumor. Epidemiology There may be a greater female incidence (with reported M:F = 2:3), with peak incidence thought to be around the age of 30-40 years. Pathology Microscopic appea...

Pancreatic calcifications

Pancreatic calcifications can arise from many etiologies. Punctate intraductal calcifications chronic pancreatitis alcoholic pancreatitis (20-40%) 2 intraductal, numerous, small, irregular preponderant cause of diffuse pancreatic intraductal calcification gallstone pancreatitis (2%) 2 m...

Dysplastic liver nodules

Dysplastic liver nodules are focal nodular regions (≥1 mm) without definite evidence of malignancy. Epidemiology They have been found in cirrhotic patients with a prevalence of 14% (size >1.0 cm) to 37% (size >0.5 cm) 2. Associations cirrhosis Pathology Dysplasia indicates: nuclear atypia...

Hutson loop

A Hutson loop, also known as an access loop, is variation of the Roux-en-Y choledochojejunostomy whereby a longer segment of jejunum is used to construct the hepatobiliary limb, and the upstream end is tacked to the anterior abdominal wall ("stomatization") 4. The goal is to simplify future end...

CA 19-9

CA 19-9 (carbohydrate antigen 19-9 or cancer antigen 19-9) is a serum antigen (monosialoganglioside) that has increased diagnostic use in the management of several malignancies, mainly of hepatopancreaticobiliary origin. It is non-specific, however, and can rise in both malignant and non-maligna...

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...

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 ~5% (range 2-7%) of the population 1,2. There may be a slight female p...

Hepatic mesenchymal hamartoma

Hepatic mesenchymal hamartomas are uncommon benign hepatic lesions that are mostly seen in children under the age of 2. Some authors consider them to be developmental anomalies rather than cystic neoplasia 9,12. Epidemiology Hepatic mesenchymal hamartomas typically occur in children and neona...

Abernethy malformation

Abernethy malformations are rare vascular anomalies of the splanchnic venous system. They consist of congenital portosystemic shunts and result from persistence of the embryonic vessels. Epidemiology Type I malformations are thought to occur only in females, while type II have a male predomin...

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 ...

Hemorrhagic pancreatitis

Hemorrhagic pancreatitis is characterized by bleeding within or around the pancreas, and is usually considered a late sequela of acute pancreatitis. Pathology Hemorrhage can occur in patients with severe necrotizing pancreatitis or as a result of pancreatic pseudoaneurysm rupture when it const...

Ampulla of Vater

The ampulla of Vater is a conical structure at the confluence of the common bile duct (CBD) and the main pancreatic duct that protrudes through a natural dehiscence of the duodenal wall at the major duodenal papilla into the medial aspect of the descending duodenum. The entire structure is encas...

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...

Ampullary tumor

The term ampullary tumor generally refers to either benign or malignant neoplasms that arise from the glandular epithelium of the ampulla of Vater, including 1: ampullary adenoma (adenoma of ampulla of Vater) ampullary carcinoma (carcinoma of ampulla of Vater) According to some authors, ampul...

Transient hepatic intensity difference

Transient hepatic intensity differences (THIDs) are a phenomenon observed on MRI imaging of the liver. They are considered a direct equivalent to transient hepatic attenuation differences (THADs) noted on CT. They may be focal or nonfocal. Pathology Focal lesions A focal THID lesion can arise...

Sonographic halo sign (disambiguation)

Sonographic halo sign can be useful in a number of situations: 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 i...

Selective internal radiation therapy

Selective internal radiation therapy (SIRT), also known as transarterial radioembolization (TARE) or 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 t...

Splenic infarction

Splenic infarction is a result of ischemia to the spleen, and in many cases requires no treatment. However, identification of the cause of infarction is essential. Epidemiology Splenic infarcts can occur due to a number of processes, involving either arterial supply, the spleen itself or the...

Coarsened hepatic echotexture

Coarsened hepatic echotexture is a sonographic descriptor used when the uniform smooth hepatic echotexture of the liver is lost. This can occur due to a number of reasons which include: conditions that cause hepatic fibrosis 1 cirrhosis hemochromatosis various types of hepatitis 3 particula...

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