Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

1,002 results found
Article

Gastric cancer (TNM staging)

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 tumours. TNM staging (7th edition) T T1 T1a: tumour invades the lamina propria and or muscularis mucosae  T1b: tumour invades submucosa...
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Gastric diverticulum

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.  Epidemiology Gastric diverticula are rare and commonly detected incidentally. The incidence varies from...
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Gastric duplication cyst

A gastric duplication cyst is a rare congenital foregut duplication cyst affecting the stomach. It accounts for less than 10% of all gastrointestinal duplications. The most common site of gastrointestinal tract duplication cysts (GTDCs) is the ileum, followed by oesophagus, large bowel and jejun...
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Gastric emphysema

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.  Pathology Aetiology There is a wide range of causes, ranging from life-threatening...
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Gastric leiomyoma

Gastric leiomyomas are rare benign mesenchymal tumours, usually asymptomatic and found incidentally.  Clinical presentation Most leiomyomas are found incidentally in asymptomatic patients. Symptoms related to a gastric leiomyoma will depend on the tumour size, location, and presence/absence of...
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Gastric lipoma

Gastric lipomas are a location-specific subtype of gastrointestinal lipomas and represent a rare benign mesenchymal tumours of the stomach. They can be definitively diagnosed on CT.  Epidemiology Gastric lipomas are rare, accounting for <5% of gastrointestinal lipomas and <1% of all gastric ne...
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Gastric lymph node stations

Gastric lymph node stations were originally divided into 16 groups proposed by the Japanese Research Society for Gastric Cancer in 1963. Gross anatomy The areas of stomach which drain into regional lymph nodes: cardia and proximal lesser curvature drain into left gastric lymph nodes, then int...
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Gastric metastases

Gastric metastases are rare, found in less than 2% of patients who die of a carcinoma 6. Epidemiology Usually affects the middle-aged and elderly population. Affects males and females equally without predilection. Clinical presentation The patient may be asymptomatic, but the most common sig...
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Gastric outlet obstruction

Gastric outlet obstruction is a syndrome resulting from mechanical obstruction of stomach emptying. Pathology Aetiology Gastric outlet obstruction can be due to malignant or benign causes. Malignant adenocarcinoma (second most common 4) GIST lymphoma (less commonly than other malignancies...
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Gastric polyps

Gastric polyps are uncommon findings, even on endoscopy where they are encountered in only 2-6% of patients.  Pathology There are a number of gastric polyp subtypes 1-3: non-neoplastic polyps hyperplastic polyps virtually no malignant potential typically small (<1cm), multiple, and sessile...
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Gastric ulcer evaluation (barium)

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. Radiographic fea...
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Gastric volvulus

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. Epidemiology Organo-axial volvulus...
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Gastrinoma

Gastrinomas are the second most common pancreatic endocrine tumour and the most common type in the setting of multiple endocrine neoplasia type I (MEN I). Epidemiology Most gastrinomas are sporadic, although some are seen in the setting of multiple endocrine neoplasia type I (MEN I). In genera...
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Gastrinoma triangle

The gastrinoma triangle (or Passaro's triangle) is an anatomical area in the abdomen, from where the majority (90%) of gastrinomas are thought to arise.  Gross anatomy Boundaries The triangle is formed by joining the following three points: superiorly: confluence of the cystic and common bil...
Article

Gastroduodenal artery

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...
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Gastrointestinal amyloidosis

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. Epidemiology Tends to affect middle-aged and older patients.  Clinical pres...
Article

Gastrointestinal angiodysplasia

Gastrointestinal angiodysplasias or angioectasias are one of the most common causes of occult gastrointestinal bleeding. Epidemiology Peak incidence occurs in patients in their 60-70s 3. Clinical presentation Patients can present with symptoms and signs upper or lower gastrointestinal bleedi...
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Gastrointestinal cytomegalovirus (CMV) infection

Cytomegalovirus 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.  Epidemiology Approximately 30% of...
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Gastrointestinal MRI contrast agents

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...
Article

Gastrointestinal neuroendocrine tumours

Gastrointestinal neuroendocrine tumours (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 ...
Article

Gastrointestinal nodular lymphoid hyperplasia

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. Pathology Gut-a...
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Gastrointestinal schwannoma

A gastrointestinal schwannoma is an extremely rare mesenchymal neoplasm which arises in relation to the gastrointestinal tract. Epidemiology They are reported to typically present at about the 3rd to 5th decades of life 4. Clinical presentation Patients are often asymptomatic but may occasio...
Article

Gastrointestinal stromal tumour

Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumours of the gastrointestinal tract. They account for ~5% of all sarcomas. They respond remarkably well to chemotherapy.  Terminology Previously these tumours have been variably referred to as leiomyomas, leiomyosarcomas...
Article

Gastrointestinal tract

The gastrointestinal tract includes any part of the oral cavity, oropharynx, hypopharynx, oesophagus, stomach, small bowel, colon, rectum and anal canal. 
Article

Gastrointestinal tract lipomas

Gastrointestinal tract (GIT) lipomas are not common and can be found anywhere along the entire length of the gastrointestinal tract.  Epidemiology GIT lipomas are most frequently encountered between the ages of 50 and 70 years 3. Clinical presentation The majority of lipomas are asymptomatic...
Article

Gastrointestinal tuberculosis

Gastrointestinal tuberculosis refers to the infection of abdominal organs with Mycobacterium tuberculosis. It generally affects the following organs: ileocaecal junction (terminal ileum and caecum): most commonly due to the abundance of lymphoid tissue 1 colon liver spleen peritoneum lymph...
Article

Gastro-oesophageal junction

The gastro-oesophageal junction (GOJ) (also known as the oesophagogastric junction) is the part of the gastrointestinal tract where the oesophagus and stomach are joined. Gross anatomy The GOJ is normally mostly intra-abdominal and is 3-4 cm in length. To some extent, the oesophagus slides in ...
Article

Gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GORD) is a spectrum of disease that occurs when gastric acid refluxes from the stomach into the lower end of the oesophagus across the lower oesophageal sphincter (LOS). Clinical presentation Common clinical features in adults include epigastric and retroster...
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Gastro-oesophageal reflux disease (summary)

This is a basic article for medical students and other non-radiologists Gastric-oesophageal reflux disease (GORD) is a spectrum of disease that occurs when gastric acid refluxes into the lower oesophagus Reference article This is a summary article; read more in our article on gastro-oesophage...
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Gastroschisis

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.   Epidemiology The estimated incidence is at around 1-6 per 10,000...
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Gastrosplenic ligament

The gastrosplenic ligament is a peritoneal ligament which is formed by ventral part of dorsal mesentery. Gross anatomy The gastrosplenic ligament extends from the greater curvature of the stomach to the hilum of the spleen. It contains the short gastric arteries. Related anatomy During porta...
Article

Gaucher disease

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...
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Generalised colitis (mnemonic)

A mnemonic to remember the causes of generalised colitis is: I3NR Mnemonic I: infectious colitis e.g. E. coli, cytomegalovirus I: inflammatory, e.g. pseudomembranous colitis, Crohn disease, ulcerative colitis I: ischaemic colitis N: neoplastic, e.g. lymphoma R: radiation colitis
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General topography of the abdomen

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...
Article

Geophagy

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...
Article

Giant colonic diverticulum

A giant colonic diverticulum is a rare form of presentation of colonic diverticulosis and is characterised by a large diverticular mass, usually filled with stool and gas, that communicates with the colonic lumen.   Clinical presentation The most common presentation is abdominal pain. Other pr...
Article

Globus pharyngeus

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...
Article

Glucagon

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.  Structure Glucagon is a 29-amino acid polypeptide hormone t...
Article

Glucagonoma

Glucagonomas are pancreatic endocrine tumours that secrete glucagon. Most lesions are malignant. Epidemiology 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.  Clinical presentation Most patients present with...
Article

Glycogenic acanthosis

Glycogenic acanthosis is a benign finding on oesophagography in elderly patients. Epidemiology 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.  Pathology It occurs f...
Article

Glycogen storage disease type I

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 1. Epidemiology It occurs approximately one in every 100,000 live births ...
Article

Gossypiboma

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...
Article

Graft versus host disease

Graft versus host disease (GvHD) is a frequent complication of allogeneic post haematopoietic stem cell transplantation, commonly known as bone marrow transplantation. Anti-rejection drugs have reduced the incidence, although it does still frequently occur.  Pathology Graft versus host disease...
Article

Granular mucosal pattern of the oesophagus (differential)

Granular mucosal pattern of the oesophagus represents very fine nodularity of the oesophageal mucosal surface. This finding is nonspecific and may represent: reflux oesophagitis (most common) Candida oesophagitis glycogenic acanthosis Barrett oesophagus superficial spreading oesophageal car...
Article

Great vessel space

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 process affecting other retroperitoneal spaces can also ...
Article

Griffiths point

The Griffiths point (or 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 transverse co...
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Gut fistulation

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 oesophagus when c...
Article

Gut signature sign

The gut signature sign is an ultrasound term used to describe the appearance of the gastrointestinal wall. Radiographic features  Ultrasound The bowel wall has five layers, composed of alternating hyperechoic and hypoechoic appearances. Anatomically these layers are as follows (innermost to o...
Article

Haemangiopericytoma of the spleen

Haemangiopericytomas of the spleen are very rare vascular neoplasm with only a few case reports available at the time of writing. Clinical presentation Splenic haemangiopericytomas are typically asymptomatic or can result in splenomegaly. Pathology These are soft tissue vascular neoplasms ar...
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Haematopoietic stem cell transplantation (abdominal complications)

Abdominal complications of haematopoietic stem cell transplantation can occur early (0-100 days) or late (>100 days) post-transplant.  Complications Early bacterial infections, e.g. pseudomembranous colitis fungal infections, often affecting the oesophagus or as hepatic/splenic microabscesse...
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Haemochromatosis (pancreatic manifestations)

Pancreatic manifestations of haemochromatosis typically occur with primary haemochromatosis, as the organ is usually spared in the secondary form of the disease.  Pathology Iron deposition can occur in the pancreas with primary hemochromatosis. Pancreatic involvement is uncommon in patients wi...
Article

Haemoperitoneum

Haemoperitoneum is the presence of blood within the peritoneal cavity. Pathology Aetiology penetrating or non-penetrating abdominal trauma (often with associated organ injury) 1 ruptured ectopic pregnancy ovarian cyst rupture aneurysm or pseudoaneurysm rupture neoplasm rupture acute haem...
Article

Haemorrhagic pancreatitis

Haemorrhagic pancreatitis is a possible uncommon complication that can occur with pancreatitis and is characterised by bleeding within or around the pancreas. It is usually considered a late sequela of acute pancreatitis. Pathology Haemorrhage can occur in patients with severe necrotising panc...
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Haemosuccus pancreaticus

Haemosuccus pancreaticus, also known as pseudohaemobilia or haemoductal pancreatitis, is defined as upper gastrointestinal tract haemorrhage originating from the pancreatic duct into the duodenum via the ampulla of Vater, or major pancreatic papilla. Epidemiology male:female ratio is 7:1 high...
Article

Haggitt level

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...
Article

Hampton line

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...
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Haustral folds

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 caecum to the rectum. These muscular band...
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Haustral markings

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.
Article

Hepatic and splenic tuberculosis

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. Pathology Two types of lesions are known: micronodular (common) macronodular (...
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Hepatic edge sign

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.
Article

Hepatic pseudolesion near falciform ligament

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...
Article

Hepatoduodenal ligament

Hepatoduodenal ligament is the peritoneal ligament of lesser omentum, which attaches the duodenum to the liver. Hepatoduodenal ligament contains: portal vein hepatic artery  common hepatic duct  part of cystic duct Hepatoduodenal ligament is a rout of spread of diseases of pancratic head t...
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Hepatogastric ligament

The hepatogastric (gastrohepatic) ligament is a peritoneal ligament that together with the hepatoduodenal ligament forms the lesser omentum. It derives from the embryonic ventral mesentery. Gross anatomy The hepatogastric ligament extends from the fissure of the ligamentum venosum and porta he...
Article

Hepatorenal syndrome

Hepatorenal syndrome refers to a form of acute kidney injury caused by changes in renal blood flow regulation due to liver pathology 1. Although the syndrome occurs mainly in cirrhotic livers it has been reported in patients with acute fulminant liver failure as well 1. Epidemiology The incide...
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Hereditary breast and ovarian cancer syndrome

Hereditary breast and ovarian cancer (HBOC) syndrome is caused by a mutation to either BRCA1 or BRCA2 genes. These patients have an increased risk of breast cancer, ovarian cancer, pancreatic cancer and prostate cancer. However, these gene mutations are not the only cause of hereditary breast ca...
Article

Hereditary haemorrhagic telangiectasia

Hereditary haemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is a rare inherited disorder characterised by abnormal blood vessel formation in the skin, mucous membranes, and organs including the lungs, liver, and central nervous system. Epidemiology Worldwide prevale...
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Hereditary non-polyposis colorectal cancer

Hereditary non-polyposis colorectal cancer (HNPCC), also known as Lynch syndrome, is an inherited condition which predisposes to a host of malignancies, including colorectal carcinoma. It is considered the most frequent form of hereditary colorectal cancer. Diagnosis requires evaluation using cl...
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Hereditary pancreatitis

Hereditary pancreatitis is a rare subtype of chronic pancreatitis that has an autosomal dominant inheritance. Imaging plays a role in excluding underlying abnormalities. Clinical presentation As a congenital condition, presentation with acute pancreatitis attacks typically occurs in childhood,...
Article

Herpes oesophagitis

Herpes oesophagitis is one of the infectious oesophagitis that usually affects immunocompromised patients.  Epidemiology  It occurs as an opportunistic infection in immunocompromised patients, particularly those with AIDS. It has also been described in immunocompetent individuals 3. Pathology...
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Heyde syndrome

Heyde syndrome is an association between aortic valve stenosis and gastrointestinal haemorrhage. The aetiology of the gastrointestinal bleeding in this setting is uncertain, but it is thought to be related to intestinal angiodysplasia. The strength of this association independent of age-related...
Article

Hiatus hernia

Hiatus hernias occur when there is herniation of abdominal contents through the oesophageal hiatus of the diaphragm into the thoracic cavity. Epidemiology The prevalence of hiatus hernia increases with age, with a slight female predilection. Clinical presentation Many patients with hiatus he...
Article

Hiccups

Hiccups (or hiccoughs), medical term singultus, are an unpleasant phenomenon, experienced by everyone on occasion, and usually self-limiting. However the much rarer intractable chronic form can be extremely debilitating. Epidemiology Hiccups are a symptom that has probably been experienced by ...
Article

Hide-bound sign (bowel)

The hide-bound bowel sign refers to an appearance on a barium study of the small bowel in patients with scleroderma. The sign describes the narrow separation between the valvulae conniventes which are of normal thickness despite dilatation of the bowel lumen.   Although the term hide-bound is u...
Article

High-grade appendiceal mucinous neoplasms

High-grade appendiceal mucinous neoplasms (HAMN) are rare mucinous tumours of the appendix showing high-grade cytologic atypia, cf. low-grade appendiceal mucinous neoplasms (LAMN). The distinction between both LAMN and HAMN is done on histological grounds and these tumours look the same on imagi...
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Hinchey classification of acute diverticulitis

E J Hinchey et al. 3 proposed a classification for acute diverticulitis, that has been variously adapted, and is useful not only in academia but also in outlining successive stages of severity. Classification stage 1a: phlegmon stage 1b: diverticulitis with pericolic or mesenteric abscess st...
Article

Hirschsprung disease

Hirschsprung disease is the most common cause of neonatal colonic obstruction (15-20%). It is commonly characterised by a short segment of colonic aganglionosis affecting term neonates, especially boys.  Epidemiology Hirschsprung disease affects approximately 1:5000-8000 live births. In short ...
Article

HIV/AIDS

Acquired immunodeficiency syndrome (AIDS) is an immunosuppressed state, caused by infection with the human immunodeficiency virus (HIV). It is characterised by opportunistic infections, neoplasms and neurological manifestations. Epidemiology According to the United Nations programme on HIV/AID...
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HIV/AIDS: gastrointestinal manifestations

Gastrointestinal manifestations of AIDS are protean and can be broadly divided into opportunistic infections and tumours: Infections viral  cytomegalovirus (CMV) herpes simplex virus (HSV) primary infection with HIV fungal candidiasis histoplasmosis bacterial tuberculosis mycobacteriu...
Article

HIV associated neoplasms

HIV-associated neoplasms are numerous and can be broadly divided into two groups: AIDS-defining malignancies associated but not AIDS defining malignancies AIDS-defining malignancies The development of these malignancies in HIV affected individuals generally implies progression to AIDS 4: Ka...
Article

HIV oesophagitis

HIV oesophagitis is a possible cause of odynophagia in immunosuppressed patients with HIV. Epidemiology The actual incidence and prevalence of Idiopathic oesophagitis of HIV are unknown. Most of the patients have acquired immunodeficiency syndrome (AIDS) and CD4 count <100 3. Clinical present...
Article

Hydatid disease

Hydatid cysts result from infection by the Echinococcus, and can result in cyst formation anywhere in the body.  Pathology There are two main species of the Echinococcus tapeworm 1,2: Echinococcus granulosus commoner pastoral: dog is a main host; most common form sylvatic: wolf is a main h...
Article

Hyperattenuating ring sign in epiploic appandagitis

The hyperattenuating ring sign is a sign that has been described with epiploic appendagitis and refers to a hyperattenuating ring of visceral peritoneum surrounding an inflamed epiploic appendage 1. On CT it can be seen as a ring of soft tissue surrounding a region of fat attenuation adjacent to...
Article

Hypercontracting (nutcracker) oesophagus

Hypercontracting (nutcracker) oesophagus is a motility disorder of the oesophagus. This condition is primarily diagnosed with manometry with high intra-oesophageal pressure and normal peristalsis. Most patients will have a normal barium swallow.  Hypercontracting oesophagus ("nutcracker oesopha...
Article

Hypertriglyceridaemia-induced pancreatitis

Hypertriglyceridaemia-induced pancreatitis is an uncommon form of acute pancreatitis caused by high levels of circulating triglycerides in the blood. Epidemiology Hypertriglyceridaemia-induced pancreatitis accounts for around 1-4% of cases of acute pancreatitis and is the third most common cau...
Article

Hypertrophic pyloric stenosis (ultrasound measurements mnemonic)

Hypertrophic pyloric stenosis can be characterised in ultrasound studies by the measurements of the hypertrophic muscle. Although the criteria can vary from publication to publication, an easy way to keep in mind those values is remembering the first digits of the number "pi", also represented b...
Article

Ice pick sign

The ice pick sign is a smooth tapered narrowing of the upstream pancreatic duct distal to the pancreatic lesion seen frequently in benign pancreatic lesions such as a focal autoimmune pancreatitis, this is due to the extrinsic narrowing of the duct secondary to periductal fibrosis and inflammati...
Article

Idiopathic eosinophilic oesophagitis

Idiopathic eosinophilic oesophagitis is a cause of dysphagia, most commonly seen in males aged 20-40. On a barium swallow, there is a distinctive stricture seen with ring-like indentations.
Article

IgG4-related disease

IgG4-related disease (IgG4-RD) is a systemic disease that is characterised by extensive IgG4-positive plasma cells and T-lymphocyte infiltration of various organs. Terminology This condition has been known by many other names in the past, such as IgG4-related sclerosing disease, IgG4-related s...
Article

Ileal atresia

Ileal atresia is a congenital abnormality where there is significant stenosis or complete absence of a portion of the ileum. There is an increased incidence in those with chromosomal abnormalities. This article will focus on ileal atresia alone but bear in mind that some cases correspond to jej...
Article

Ileocaecal valve

The ileocaecal valve separates the terminal ileum from the caecum and functions to regulate flow between these two structures and prevent reflux from the caecum into the small intestine.  Gross anatomy The ileocaecal valve consists of two muscular layers of ileum, an upper and lower lip, that ...
Article

Ileocolic artery

The ileocolic artery is a branch of the superior mesenteric artery (SMA) that runs obliquely to the ileocaecal junction. It divides into an ileal branch that supplies the terminal ileum and anastomoses with the terminal SMA and a colic branch that supplies the proximal ascending colon and anast...
Article

Ileum

The ileum is the final part of the small intestine, following the duodenum and jejunum. Terminology The ileum is not to be confused with the ilium - the associated plural/adjectival forms are ilea/ileal and ilia/ilial respectively. Gross anatomy The ileum is 2-4 m in length and is separated ...
Article

Ilium vs ileum

The medical terms ileum and ilium have been causing great confusion to medical students and junior doctors alike for decades now. Only separated by one letter, the second vowel, the pronunciation may be identical, or differ slightly with the i sound resembling that in "bit" for ilium (ɪlɪəm) or ...

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