The foramina of Morgagni, also known as the sternocostal triangles, are small defects in the posterior aspect of the anterior thoracic wall between the sternal and costal attachments of the diaphragm. The internal thoracic vessels descend through these foramina to become the superior epigastric ...
Foregut duplication cysts are a type of congenital duplication cyst. They are sometimes classified under bronchopulmonary foregut malformations.
Entities classified as foregut duplication cysts include:
other enteric cysts
esophageal duplication cysts
This is a basic article for medical students and other non-radiologists
Free intraperitoneal fluid may be termed free fluid or (less correctly) free intra-abdominal fluid. It may be seen in small volumes in female patients, particularly around the time of menses and in some healthy young men.
The Frey procedure is a type of pancreaticojejunostomy designed to treat chronic pancreatitis.
The fundamental technique is similar to the Puestow procedure, with a lateral incision of the pancreatic duct from an anterior approach, and then a side-to-side anastomosis between the pancreas and a ...
The Frimann-Dahl sign is a diagnostic sign demonstrated when three dense lines, representing the sigmoid walls, are seen converging to the site of obstruction in sigmoid volvulus and associated with empty rectal gas 1.
History and etymology
Johan Frimann-Dahl (1902-82) was a Norwegian Professo...
Frostberg inverted 3 sign is a radiological sign seen on a barium examination where there is effacement and distortion of the mucosal pattern on the medial wall of the second part of the duodenum due to focal mass and local edema. It is most commonly associated with carcinoma of the head of the ...
Fukuoka consensus guidelines, also referred to as the Tanaka criteria, is a classification system for intraductal papillary mucinous neoplasms (IPMNs) and mucinous cystic neoplasms (MCNs).
The prior international consensus guidelines (2006) were referred to as the Sendai criteria, which later ...
The functional gastrointestinal disorders (FGIDs) are a set of conditions characterized by their chronic GI manifestations, in the absence of structural abnormality of the gut. These conditions are common and may be disabling in nature. The understanding of their pathogenesis is incomplete, comp...
Fundic gland polyps (FGP) are the most common type of gastric polyp.
FGPs occur most commonly in middle-aged females. They have been reported to be identified in ~1% of gastroscopies 3,4.
FGPs are usually an asymptomatic, incidental finding 1.
Fundoplications are forms of antireflux surgery used as a second line of treatment of gastroesophageal reflux disease after failure of medical treatment and first line of treatment of paraesophageal hernia.
A gastric fold is wrapped around the distal esophagus which enforces the lowe...
Agenesis of the gallbladder is a rare congenital anomaly.
overall incidence is estimated <0.1% (range 0.04-0.1%)
reported 3:1 female predominance of symptomatic cases
equivalent gender distribution in autopsy cases
Most patients with agenesis of...
Gallbladder triplication is an extremely rare anomaly. There are three types of gallbladder triplication are described according to the number of cystic duct and their insertion:
Three gallbladders and three cystic ducts which unite to form a common cystic duct before joining the common bile du...
Gallstone ileus is an uncommon cause of a mechanical small bowel obstruction. It is a rare complication of chronic cholecystitis 7 and occurs when a gallstone passes through a fistula between the gallbladder and small bowel before becoming impacted at the ileocecal valve.
Gallstone pancreatitis refers to pancreatitis caused by gallstones, specifically distal choledocholithiasis. Gallstones is the cause for 35-40% of acute pancreatitis but this number has a wide regional variance.
Gallstone pancreatitis has a higher incidence in women (compared to ...
Gardner syndrome is one of the polyposis syndromes. It is characterized by:
multiple osteomas: especially of the mandible, skull, and long bones
desmoid tumors of mesentery and anterior abdominal wall
Other abnormalities include:
A gasless abdomen refers to a paucity of gas on abdominal radiography, and the specific cause can usually be identified when the patient's history is known. Common causes include:
small bowel obstruction
Gastric adenocarcinoma, commonly referred to as gastric cancer, refers to a primary malignancy arising from the gastric epithelium. It is the most common gastric malignancy.
Gastric cancer is rare before the age of 40, but its incidence steadily climbs after that and peaks in the...
Gastric antral vascular ectasia (GAVE), also known as watermelon stomach, is a rare condition affecting the stomach. It is one of the diagnoses to consider in older patients with severe anemia and occult or profuse gastrointestinal bleeding (especially in those with cardiac, liver, or renal dise...
Gastric antral webs are a ring of mucosa in the distal stomach (gastric antrum) that can lead to gastric outlet obstruction. A circumferential ring of mucosa has also been termed a "gastric antral diaphragm".
Gastric antral webs are rare. There is an association with trisomy 21 an...
A gastric band is a surgically placed device, used to assist in weight loss. It is now the most popular form of bariatric surgery, largely replacing gastric bypass procedures 1.
Performed laparoscopically, a silicone band device is placed around the stomach to reduce its volume. The band is adj...
Gastric band malposition is an early complication from laparoscopic gastric band procedures which are performed for obesity. It can occur as in isolation or with other gastric band complications.
As surgical experience of lap gastric banding has accumulated, it has become a relatively rare comp...
Gastric band slippage is a late complication of laparoscopic gastric banding surgery performed for obesity. It is reported to occur in 4-13% of cases 1-3.
It can occur in either an anterior or posterior direction.
Patients can present with cessation of weight loss, sever...
Gastric band erosion or penetration is a potentially serious complication following laparoscopic gastric band surgery for obesity.
Gastric band erosion is a delayed complication observed in between 0.3-14% of patients 1-2.
Patients often present non-specif...
The gastric bubble is a radiolucent rounded area generally nestled under the left hemidiaphragm representing gas in the fundus of the stomach.
On a lateral radiograph, the gastric bubble is usually located between the abdominal wall and spine. It can be seen on chest or abdominal plain films. I...
This is a basic article for medical students and other non-radiologists
Gastric cancer, also known as stomach cancer or gastric carcinoma, refers to a cancer that arises from the mucosal lining of the stomach. It is the commonest gastric malignancy.
This is a summary article...
Gastric cancer staging is routinely performed using the TNM staging system. This article is based on the 7th edition of the TNM classification of malignant tumors.
TNM staging (7th edition)
T1a: tumor invades the lamina propria and or muscularis mucosae
T1b: tumor invades submucosa
Gastric diverticula are sac-like projections that usually originate from the gastric fundus, most commonly on the posterior surface. They are the least common gastrointestinal diverticulum.
Gastric diverticula are rare and commonly detected incidentally. The incidence varies from...
Gastric duplication cysts are rare congenital foregut duplication cysts affecting the stomach. Gastrointestinal tract duplication cysts (GTDCs) most commonly affect the ileum, followed by the esophagus, large bowel, and jejunum; gastric location accounts for less than 10% of all gastrointestinal...
Gastric emphysema, referring to the presence of gas in the wall of the stomach, is a relatively rare imaging finding 1. The stomach is the least common location for intramural gas in the gastrointestinal tract.
There is a wide range of causes, ranging from life-threatening...
Gastric leiomyomas are rare benign mesenchymal tumors, usually asymptomatic and found incidentally.
Most leiomyomas are found incidentally in asymptomatic patients. Symptoms related to a gastric leiomyoma will depend on the tumor size, location, and presence/absence of u...
Gastric lipomas are a location-specific subtype of gastrointestinal lipomas and represent a rare benign mesenchymal tumors of the stomach. They can be definitively diagnosed on CT.
Gastric lipomas are rare, accounting for <5% of gastrointestinal lipomas and <1% of all gastric neo...
Gastric lymph node stations were originally divided into 16 groups proposed by the Japanese Research Society for Gastric Cancer in 1963.
The areas of stomach which drain into regional lymph nodes:
cardia and proximal lesser curvature drain into left gastric lymph nodes, then int...
Gastric lymphoma may either represent secondary involvement by systemic disease or primary malignancy confined to the stomach.
Gastric lymphoma represents the most common site of extranodal lymphoma, accounting for 25% of all such lymphomas, 50% of all gastrointestinal lymphomas...
Gastric metastases are rare, found in less than 2% of patients who die of a carcinoma 6.
Usually affects the middle-aged and elderly population. Affects males and females equally without predilection.
The patient may be asymptomatic, but the most common sig...
Gastric outlet obstruction is a syndrome resulting from mechanical obstruction of stomach emptying.
Gastric outlet obstruction can be due to malignant or benign causes.
adenocarcinoma (second most common 4)
lymphoma (less commonly than other malignancies ...
Gastric polyps are uncommon findings, even on endoscopy where they are encountered in only 2-6% of patients.
There are a number of gastric polyp subtypes 1-3:
virtually no malignant potential
typically small (<1cm), multiple, and sessile...
Gastric (peptic) ulcers can be detected on multiple imaging modalities, but are best evaluated on a double contrast barium upper GI study. This article discusses their appearance on a double contrast study, for a more complete description, see the full article on peptic ulcers.
Gastric varices are an important portosystemic collateral pathway, occurring in ~20% of patients with portal hypertension. They are considered distinct from esophageal varices in that they have a propensity to hemorrhage at comparatively lower portal pressures 1, and are also associated with hig...
Gastric volvulus is a specific type of volvulus that occurs when the stomach twists on its mesentery. It should be at least 180° and cause bowel obstruction to be called gastric volvulus. Merely gastric rotation on its root is not considered gastric volvulus.
Gastric wall fatty infiltration refers to an appearance seen on CT of the abdomen whereby the wall of the stomach is thickened due to infiltration of fat into the submucosa.
Although it can be seen in the context of Crohn disease it is more commonly seen in the asymptomatic general population. ...
Gastrinomas are the second most common pancreatic endocrine tumor and the most common type in the setting of multiple endocrine neoplasia type I (MEN I).
Most gastrinomas are sporadic, although some are seen in the setting of multiple endocrine neoplasia type I (MEN I). In general...
The gastrinoma triangle, also known as Passaro's triangle, is an anatomical area in the abdomen, from where the majority (90%) of gastrinomas are thought to arise.
The triangle is formed by joining the following three points:
superiorly: confluence of the cystic and...
The gastroduodenal artery (GDA) is a terminal branch of the common hepatic artery which mainly supplies the pylorus of the stomach, proximal duodenum, and the head of the pancreas. Due to its proximity to the anterior wall of the first part of the duodenum, the gastroduodenal artery is one of th...
Gastrointestinal amyloidosis is relatively common, although symptomatic involvement is more rare. It is diagnosed if there is persistent gastrointestinal (GI) symptoms with endoscopic biopsy proven amyloid deposition.
Tends to affect middle-aged and older patients.
Gastrointestinal angiodysplasias or angioectasias are one of the most common causes of occult gastrointestinal bleeding.
Peak incidence occurs in patients in their 60-70s 3.
Patients can present with symptoms and signs upper or lower gastrointestinal bleedi...
Cytomegalovirus (CMV) infection of the gastrointestinal tract is usually seen in patients who are severely immunocompromised, such as solid organ transplantation and is common in HIV/AIDS, and is, in fact, the most common gastrointestinal manifestation of AIDS 1,2.
Gastrointestinal MRI contrast agents are varied and can be either positive or negative agents. Acceptance of the use of MRI in abdominal imaging has been limited in part by difficulty in distinguishing bowel from intra-abdominal masses and normal organs. The use of enteric contrast agents can ai...
Gastrointestinal neuroendocrine tumors (GI NETs) can be functional or non-functional:
functional NETs can be challenging to localise as:
they are often small in size at the time of diagnosis
arise in many sites throughout the body
non-functioning and/or malignant NETs often are larger at p...
Gastrointestinal nodular lymphoid hyperplasia is a type of nodular lymphoid hyperplasia that can be found elsewhere in the body. It is formed out of gut-associated lymphoid tissue (GALT), and most often is a diagnostic dilemma for radiologists in the stomach and terminal ileum.
Gastrointestinal schwannomas are extremely rare mesenchymal neoplasms which arise in relation to the gastrointestinal tract.
They are reported to typically present at about the 3rd to 5th decades of life 4.
Patients are often asymptomatic but may occasional...
Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract. They account for ~5% of all sarcomas. They respond remarkably well to chemotherapy.
Previously these tumors have been variably referred to as leiomyomas, leiomyosarcomas, a...
The gastrointestinal tract includes any part of the oral cavity, oropharynx, hypopharynx, esophagus, stomach, small bowel, colon, rectum and anal canal.
Gastrointestinal tract lipomas are not uncommon and can be found anywhere along the entire length of the gastrointestinal tract.
Gastrointestinal tract lipomas are most frequently encountered between the ages of 50 and 70 years 3.
The majority of lipomas a...
Gastrointestinal tuberculosis refers to the infection of abdominal organs with Mycobacterium tuberculosis. It generally affects the following organs:
ileocecal junction (terminal ileum and cecum): most commonly due to the abundance of lymphoid tissue 1
The gastro-esophageal junction (GOJ) (also known as the oesophagogastric junction) is the part of the gastrointestinal tract where the esophagus and stomach are joined.
The GOJ is normally mostly intra-abdominal and is 3-4 cm in length. To some extent, the esophagus slides in and...
Gastro-esophageal reflux disease (GORD) is a spectrum of disease that occurs when gastric acid refluxes from the stomach into the lower end of the esophagus across the lower esophageal sphincter (LOS).
Common clinical features in adults include epigastric and retrosternal...
This is a basic article for medical students and other non-radiologists
Gastric-esophageal reflux disease (GORD) is a spectrum of disease that occurs when gastric acid refluxes into the lower esophagus
This is a summary article; read more in our article on gastro-esophageal ...
A gastro-pleural fistula is a very rare situation characterized by a pathological communication between the stomach and the pleural cavity.
They can occur in number of situations:
trauma (stab injuries 3)
iatrogenic (following bariatric, pulmonary or esophageal surgery 1)
Gastroschisis refers to extra-abdominal herniation (evisceration) of fetal or neonatal bowel loops (and occasionally portions or the stomach and or liver) into the amniotic cavity through a para-umbilical abdominal wall defect.
The estimated incidence is at around 1-6 per 10,000...
The gastrosplenic ligament is a peritoneal ligament which is formed by ventral part of dorsal mesentery.
The gastrosplenic ligament extends from the greater curvature of the stomach to the hilum of the spleen. It contains the short gastric arteries.
Gaucher disease (GD) is the most common lysosomal storage disease in humans. It is an autosomal recessive, multisystem disease arising from a deficiency of glucocerebrosidase or beta-glucosidase activity, resulting in accumulation of a glycolipid (glucocerebroside) within the lysosomes of macrop...
A mnemonic to remember the causes of generalized colitis is:
I: infectious colitis e.g. E. coli, cytomegalovirus
I: inflammatory, e.g. pseudomembranous colitis, Crohn disease, ulcerative colitis
I: ischemic colitis
N: neoplastic, e.g. lymphoma
R: radiation colitis
To facilitate clinical description, the general topography of the abdomen is divided into four quadrants or nine regions by lines on the surface of the anterior abdominal wall. The four quadrants are created by vertical and horizontal lines passing through the umbilicus, whereas the nine regions...
Geophagy is the intentional ingestion of earth, soil or clay and is a form of pica. This practice is not uncommon in the southern regions of the United States or provinces of Africa. It may be seen in pregnant or iron-deficient patients 3. Although geophagia may be seen in the context of a varie...
A giant colonic diverticulum is a rare form of presentation of colonic diverticulosis and is characterized by a large diverticular mass, usually filled with stool and gas, that communicates with the colonic lumen.
The most common presentation is abdominal pain. Other pres...
Globus pharyngeus is the subjective feeling of a lump in the throat which can have a variety of causes. In modern practice globus is often evaluated by flexible nasoendoscopy in the first instance since many patients present to otolaryngology services. If no cause is identified or if nasoendosco...
Glucagon is a polypeptide hormone central to the regulation of glucose homeostasis, acting as an antagonist to insulin. In imaging it is used as an antiperistaltic agent in GI studies, although its clinical efficacy is controversial.
Glucagon is a 29-amino acid polypeptide hormone t...
Glucagonomas are pancreatic endocrine tumors that secrete glucagon. Most lesions are malignant.
They are very rare with an incidence of ~0.000005% or less than 1 case per 20 million. Equal incidence in middle-aged men and women.
Most patients present with ...
Glycogenic acanthosis is a benign finding on esophagography in elderly patients.
It most commonly occurs in patients >40 years of age and incidence and numbers of lesions increase by age. No gender predilection exists. Typically patients are asymptomatic.
It occurs fr...
Glycogen storage disease type I (GSD-I), also known as von Gierke disease, is a type of glycogen storage disease where there is excess deposition of glycogen primarily in the liver, but also in the kidney and small bowel.
It occurs approximately one in every 100,000 live births 2,...
A gossypiboma, also called textiloma or cottonoid, refers to a foreign object, such as a mass of cotton matrix or a sponge, that is left behind in a body cavity during an operation. It is an uncommon surgical complication.
The manifestations and complications of gossypibomas are so variable tha...
Graft versus host disease (GvHD) is a frequent complication of allogeneic post hematopoietic stem cell transplantation, commonly known as bone marrow transplantation. Anti-rejection drugs have reduced the incidence, although it does still frequently occur.
Graft versus host disease ...
Granular mucosal pattern of the esophagus represents very fine nodularity of the esophageal mucosal surface. This finding is nonspecific and may represent:
reflux esophagitis (most common)
superficial spreading esophageal carcinoma...
The great vessel space is the fourth retroperitoneal space along with the anterior and posterior pararenal spaces, and the perirenal space 1,2. Unlike other retroperitoneal spaces, it is not well-defined by fascial planes and thus disease processes affecting other retroperitoneal spaces can also...
The Griffiths point, also known as Griffiths critical point, refers to the site of watershed anastomosis between the ascending left colic artery and the marginal artery of Drummond occurring in the region of the splenic flexure. Most anatomy texts describe the location as two-thirds along the tr...
Gullo syndrome, also known as benign pancreatic hyperenzymaemia, is characterized by the abnormal elevation of the serum levels of most or all of the pancreatic enzymes without any evidence of underlying pancreatic pathology. All other laboratory assays and imaging studies are unremarkable.
A gastrointestinal fistula is an abnormal connection between the gut and another epithelial / endothealial - lined surface, such as another organ system, the skin surface, or elsewhere along the gastrointestinal tract. Some authors exclude fistulas involving the large bowel and esophagus when cl...
The gut signature sign is an ultrasound term used to describe the appearance of the gastrointestinal wall.
The bowel wall has five layers, composed of alternating hyperechoic and hypoechoic appearances. Anatomically these layers are as follows (innermost to o...
Hemangiopericytomas of the spleen are very rare vascular neoplasm with only a few case reports available at the time of writing.
Splenic hemangiopericytomas are typically asymptomatic or can result in splenomegaly.
These are soft tissue vascular neoplasms aris...
Abdominal complications of hematopoietic stem cell transplantation can occur early (0-100 days) or late (>100 days) post-transplant.
bacterial infections, e.g. pseudomembranous colitis
fungal infections, often affecting the esophagus or as hepatic/splenic microabscesses
Pancreatic manifestations of hemochromatosis typically occur with primary hemochromatosis, as the organ is usually spared in the secondary form of the disease.
For a general discussion, and for links to other system specific manifestations, please refer to the article on hemochromatosis.
Hemoperitoneum is the presence of blood within the peritoneal cavity.
penetrating or non-penetrating abdominal trauma (often with associated organ injury) 1
ruptured ectopic pregnancy
ovarian cyst rupture
aneurysm or pseudoaneurysm rupture
Hemorrhagic pancreatitis is a possible uncommon complication that can occur with pancreatitis and is characterized by bleeding within or around the pancreas. It is usually considered a late sequela of acute pancreatitis.
Hemorrhage can occur in patients with severe necrotizing pancre...
Haemosuccus pancreaticus, also known as pseudohaemobilia or haemoductal pancreatitis, is defined as upper gastrointestinal tract hemorrhage originating from the pancreatic duct into the duodenum via the ampulla of Vater, or major pancreatic papilla.
male:female ratio is 7:1
The Haggitt level is a histopathological term used for describing the degree of infiltration from a malignant polypoidal lesion.
Levels of invasion
0: carcinoma in situ or intramucosal carcinoma
1: invasion of the submucosa, but limited to the head of the polyp
2: invasion extending into the...
The Hampton line is a thin millimetric radiolucent line seen at the neck of a gastric ulcer in barium studies (profile view), indicating its benign nature. It is caused by a thin line of mucosa overhanging the ulcer's crater.
History and etymology
It was originally described by Aubrey Otis Ham...
Hartmann pouches are a technique in colon surgery. After a segment of colon is resected, there are generally two options with regards to what to do with the two ends of the colon:
both the upstream end of the colon (the end of the colon through which fecal contents would pass) and the downstr...
Hartmann procedure (or proctosigmoidectomy) is an operation
The haustral folds represent folds of mucosa within the colon. They are formed by circumferential contraction of the inner muscular layer of the colon.
The outer longitudinal muscular layer is organised into three bands (taeniae coli) which run from the cecum to the rectum. These muscular bands...
Haustral markings are the radiological appearance of the haustral folds within the colon. Disappearance of the haustral folds results in the lead pipe appearance of ulcerative colitis.
Hepatic and splenic tuberculosis refers to tuberculosis affecting the liver and the spleen. It generally occurs due to haematogenous spread from the primary site of infection, commonly from pulmonary tuberculosis.
Two types of lesions are known:
The hepatic edge sign is a radiographic sign of pneumoperitoneum seen on a supine plain abdominal radiograph. It is represented by a cigar-shaped pocket of free air in the subhepatic region, which tracks superomedial following the contour of the liver.
Hepatic pseudolesions near the falciform ligament show abnormal attenuation without mass effect. They may be seen on contrast-enhanced CT scans as either a region of high or low attenuation relative to the rest of the liver. They are typically located in the medial segment of the left lobe of th...