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.

942 results found
Article

Meconium peritonitis

Meconium peritonitis refers to a sterile chemical peritonitis due to intra-uterine bowel perforation and spillage of fetal meconium into the fetal peritoneal cavity. It is a common cause of peritoneal calcification.  Epidemiology The estimated prevalence is at ~1 in 35,000. Pathology The aet...
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Medial fossa

The medial fossae are concave depressions of peritoneum in the paravesical space bounded by the medial umbilical folds and the lateral umbilical folds. The fossae are contained within the inguinal (Hesselbach’s) triangle. The right medial fossa typically partially contains the cecum and/or ileum...
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Medial umbilical folds

The medial umbilical folds are raised ridges of parietal peritoneum in the deep aspect of the anterior abdominal wall formed by the underlying medial umbilical ligaments. The paired folds run from pelvis to umbilicus. The medial umbilical ligaments are anatomical remnants of foetal umbilical art...
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Median umbilical fold

The median umbilical fold is a raised ridge of parietal peritoneum in the deep aspect of the anterior abdominal wall overlying the median umbilical ligament. It runs from the apex of the bladder to the umbilicus. The median umbilical ligament is the anatomical remnant of the foetal urachus. The ...
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Mediastinal pseudocyst

Mediastinal pseudocyst is the extension of pancreatic pseudocyst into the the posterior mediastinum through oesophageal or aortic hiatus or rarely through foramen of Morgagni. It is a rare complication of acute or chronic pancreatitis. Clinical presentation It can present with symptoms due to ...
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Medical devices in the abdomen and pelvis

Medical devices in the abdomen and pelvis are important to be recognised, just like medical devices of the chest. Often we ignore these devices, considering them to be incidental and non-pathological, however it is essential to be aware of potential complications. Gastrointestinal tubes stomac...
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Mega oesophagus

Mega oesophagus or diffuse oesophageal dilatation can be caused by a variety of conditions.  Pathology Aetiology Some of the more common causes are given below 1-3: oesophageal dysmotility achalasia Chagas disease scleroderma distal obstruction malignant stricture, e.g. oesophageal canc...
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Ménétrier disease

Ménétrier disease (MD) is a form of rare idiopathic hypertrophic gastropathy. Epidemiology Rare disease with incidence < 1 per 200,000. Bimodal in distribution, children often < 10 years; adult forms 30-60 years, peak 55 years. Male preponderance both in juvenile and adult form 7. Pathology ...
Article

Mercedes-Benz sign (gallbladder)

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

Mesenteric adenitis is a self-limiting inflammatory process that affects the mesenteric lymph nodes in the right lower quadrant, and is clinically often mistaken for acute appendicitis. Epidemiology Mesenteric adenitis is most common in children and adolescents although it may occasionally aff...
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Mesenteric cyst

Mesenteric cysts are a very rare cause of abdominal pain, and have a wide range of underlying causes.  Epidemiology Mesenteric cysts are rare, with a reported incidence of 0.5-1 per 100,000 admissions 3.  Clinical presentation Patients usually present with abdominal pain and/or mass, althoug...
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Mesenteric desmoid tumour

Mesenteric desmoid tumours are a subtype of desmoid tumours   Pathology Desmoids are cytologically bland tumours that appear as infiltrative, well-demarcated tumours that are derived from musculo-aponeurotic structures throughout the body.  Associations in the mesentry, the masses may occur ...
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Mesentery

A mesentery is a double layer of peritoneum that encloses the intestines and attaches them to the posterior abdominal wall. The term was originally only used to refer to the double layer of peritoneum that suspends the jejunum and ileum, but its meaning has been widened. Mesenteries include: s...
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Mesoappendix

The mesoappendix is a fold of peritoneum around the vermiform appendix and one of the four mesenteries in the abdominal cavity. It is attached to the lower end of the small bowel mesentery, close to the ileocaecal junction. It usually extends to the tip of the appendix and sometimes suspends th...
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Metaplasia

Metaplasia is a general pathology term that refers to process when one cell type is replaced by another. It usually occurs in the context of changed cellular environment to which the new cell type is better adapted 1. Examples include 2-5: Barrett oesophagus: normal squamous epithelium replaced...
Article

MIBG

MIBG scan is a scintigraphic study that uses metaiodobenzylguanidine labeled to Iodine-123 or Iodine-131. It is indicated in the investigation of phaeochromocytoma. MIBG is positive in: neuroblastoma olfactory neuroblastoma 1 carcinoid tumour 4 paraganglioma phaeochromocytoma medullary th...
Article

Middle colic artery

The middle colic artery is a branch of the superior mesenteric artery (SMA). It passes in the layers of the transverse mesocolon to the transverse colon. The middle colic artery divides into right and left branches. The right branch supplies the right portion of the transverse colon and anastom...
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Middle rectal artery

The middle rectal artery, also known as the middle haemorrhoidal artery, is a branch from the anterior division of the internal iliac artery supplying the rectum. Summary origin: anterior division of the internal iliac artery location: pelvis supply: inferior rectum, seminal vesicles, prosta...
Article

Midgut volvulus

Midgut volvulus is a complication of malrotated bowel and results in a proximal bowel obstruction and ischaemia. Epidemiology A midgut volvulus of malrotated bowel can potentially occur at any age but in approximately 75% of cases is within a month of birth 4,6, most within the first week 3, a...
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Misty mesentery

Misty mesentery is a term used to describe the CT appearance of mesenteric fat with increased attenuation. Just as with fat stranding elsewhere, a number of processes can lead to the appearance including infiltration by inflammatory cells, oedema, lymphatic accumulation, haemorrhage, tumour infi...
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Mobile caecum

Mobile caecum is an anatomical variant and is often defined as a failure of the caecum, terminal ileum, and right colon, along with the mesentery, to fuse to the posterior parietal peritoneal wall. This results in increased mobility of the caecum. Epidemiology It has been estimated to occur in...
Article

Modified CT severity index

The modified CT severity index is an extension of the original CT severity index (CTSI) was developed by Balthazar and colleagues in 1994 for distinguishing mild, moderate and severe forms of acute pancreatitis. The original CT severity index has been followed internationally and has been very ...
Article

Morgagni hernia

Morgagni hernias are one of the congenital diaphragmatic hernias (CDH), and is characterised by herniation through the foramen of Morgagni. When compared to Bochdalek hernias, Morgagni hernias are: anterior more often right-sided (~90%) small rare (~2% of CDH) at low risk of prolapse Clini...
Article

Moulage sign (bowel)

The moulage sign is related to sprue, in particular coeliac disease. It occurs where there is a dilated jejunal loop with complete loss of jejunal folds 1. It is said to appear like a tube into which wax has been poured. History and etymology Moulage (French: casting/moulding) is the art of ap...
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MR defaecating proctography

MR defecography is a dynamic study for evaluation of the pelvic floor and pelvic organ prolapse. Phases There are four phases of evaluation: rest squeeze strain (Valsalva) defaecation Method of evaluation Many variations in the techniques described below exist. Patient preparation Typi...
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MR enteroclysis

MR enteroclysis is a technique for evaluation of number of small bowel diseases (especially Crohn disease) using MRI. Technique A general technique is outlined below placement of a nasoduodenal tube under fluoroscopic guidance the small-bowel is distended with 1-3 L of methylcellulose (0.5%)...
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MR enterography

MR enterography is a new non-invasive technique for diagnosis of small bowel disorders. Indications The most common indication is to evaluate patients with Crohn disease (CD). Technique Actual procedure will vary depending on institutional protocol/guidelines but below is a typical descripti...
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Mucinous adenocarcinoma of the appendix

Mucinous adenocarcinomas of the appendix are on the malignant end of the spectrum of the mucinous neoplasms that affect the caecal appendix.  For the mucinous carcinomas involving the remainder of the colon, please refer to the article on mucinous carcinoma of the colon. Epidemiology Peak inc...
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Mucinous carcinoma of the colon

Mucinous carcinoma of the colon is a distinct form of colorectal cancer found in 10-15% of patients with colorectal cancer. It differs from the conventional adenocarcinoma in terms of clinical and histopathological characteristics. For the caecal appendix, please refer to the article on mucinou...
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Mucinous cystadenocarcinoma of the pancreas

Mucinous cystadenocarcinomas of the pancreas are a type of pancreatic mucinous tumour. It is considered the more malignant counterpart of a mucinous cystadenoma of the pancreas. Epidemiology Like the more benign mucinous cystadenomas, these are found almost exclusively in females 4. Radiograp...
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Mucinous cystadenoma of the pancreas

Mucinous cystadenomas (MCN) of the pancreas are a type of mucinous cystic neoplasm of the pancreas. Epidemiology Previously believed to occur exclusively in middle age females 5, it has occasionally been described in males 6-7. Pathology It is a large uni/multilocular cystic pancreatic neopl...
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Mucinous cystic neoplasms of the pancreas

Mucinous cystic neoplasms of the pancreas are the most common cystic neoplasm of the pancreas and include: mucinous cystadenoma of pancreas mucinous cystadenocarcinoma of pancreas intraductal papillary neoplasms (IPMN) of the pancreas: sometimes classified separately
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Mucinous neoplasms of the appendix

Mucinous neoplasms of the appendix are epithelial tumours of the appendix that produce mucin. According to a panel of specialists consensus published in 2016, a new nomenclature and classification for the appendiceal mucinous neoplasms based on their histologic type and biologic behaviour has be...
Article

Muir-Torre syndrome

Muir-Torre syndrome is a rare variant of hereditary nonpolyposis colorectal cancer (HNPCC),  characterised by sebaceous neoplasms (e.g adenoma, epithelioma or carcinoma) and keratoacanthocytomas as well as at least one internal malignancy: gastrointestinal malignancies (most common of internal ...
Article

Multiple endocrine neoplasia type I

Multiple endocrine neoplasia type I (MEN1) is also known as Wermer syndrome. Clinical presentation Primary hyperparathyroidism is one of the commonest presentations. Pathology The abnormality is related to a tumour suppressor gene located in chromosome 11q13. MEN type I is an autosomal domin...
Article

Mushroom cap sign

Mushroom cap sign is one of the important signs of deep rectosigmoid endometriosis seen on T2 weighted MRI sequence. It indicates the submucosal involvement in rectosigmoid region. Radiographic appearance MRI Hypertrophic muscularis propria appears as heterogeneous low signal intensity surrou...
Article

Mushroom sign (pyloric stenosis)

The mushroom sign (also called umbrella sign) is a radiological sign described in pyloric stenosis on barium examination. This sign refers to the impression made by the hypertrophic pylorus on the duodenal cap. See also shoulder sign cervix sign of pyloric stenosis target sign of pyloric st...
Article

Mycosis fungoides

Mycosis fungoides (MF), also known as cutaneous T-cell lymphoma, is a type of malignant T-cell lymphoma that primarily involves the skin.  Epidemiology In the United States, it is more common in males and African Americans. In Europe, it accounts for ~6% of all non-Hodgkin lymphomas. It is rar...
Article

Myochosis coli

Myochosis coli is an uncommonly used term to denote the shortening and thickening of the colon seen in diverticulosis.  This is due to shortening of the taenia coli and thickening of the circular muscular layer 1.
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Nasogastric tube positioning

Assessment of nasogastric (NG) tube positioning is a key competency of all doctors as unidentified malpositioning may have dire consequences, including death. The ideal position should be in the sub-diaphragmatic position in the stomach - identified on a plain chest radiograph as overlying the ...
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Nasogastric tube position on chest x-ray (summary)

Nasogastric (NG) tube position on chest x-ray should be assessed following initial placement and on subsequent radiographs. Reference article This is a summary article; we do not have a more in-depth reference article. Summary confirming position x-rays are only performed when the position ...
Article

Necrotising enterocolitis

Necrotising enterocolitis (NEC) is the most common gastrointestinal condition in premature neonates. It is characterised by inflammation, ischaemia, and permeability of the neonatal bowel wall to bacteria. It is potentially life threatening with significant associated morbidity. Epidemiology N...
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Necrotising enterocolitis (staging)

Necrotising enterocolitis (NEC) can be staged into three groups, helping to guide appropriate treatment. In general, stage I and II are managed medically whereas stage III is managed surgically. stage I clinical signs lethargy, temperature instability, apnoea, bradycardia emesis, abdominal d...
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Necrotising pancreatitis

Necrotising pancreatitis (NP) represents the severe form of pancreatitis. It is considered a subtype of acute pancreatitis as necrosis usually tends to occurs early, within the first 24-48 hours, but can also rarely occur with subacute forms. A key feature is a significant amount of pancreatic ...
Article

Neonatal appendicitis

Neonatal appendicitis is rare, presumably in part due to the short funnel shape to the appendix at that age. Symptoms are non-specific and may mimic necrotising enterocolitis. 
Article

Neonatal pneumoperitoneum

The causes of neonatal pneumoperitoneum are different from adult pneumoperitoneum and include: perforated hollow viscus necrotising enterocolitis (NEC): most common meconium ileus in cystic fibrosis Hirschsprung disease intestinal atresia or web peptic ulcer disease iatrogenic intubation...
Article

Neoplasms of the appendix

There are a number of neoplasms that can involve the appendix, some of which are peculiar to this site. Epidemiology Tumours involving the appendix have been found in only about 1% of all appendectomy 9. Epithelial neoplasms and neuroendocrine tumours represent the gross majority of the tumour...
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Neuhauser sign (distal ileum)

Neuhauser sign refers to a soap bubble appearance seen in the distal ileum in cases of meconium ileus, related to the air mixed with meconium. It may be seen with barium enema if contrast passes beyond the ileocaecal valve or with small-bowel follow-through. Although classically described with ...
Article

Niacin deficiency

Niacin (vitamin B3) deficiency, also known as Pellagra, is a multisystemic disease with manifestations from the skin, gastrointestinal tract and central nervous system.  Epidemiology It use to be widespread until the early twenty century, but after fortification of flour with niacin it is prac...
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Nodular filling defects of duodenum (differential)

Nodular filling defects due to mucosal lesions in the duodenum are due to a number of processes. For a differential list which includes non-mucosal lesions see duodenal filling defects. The differential diagnosis for mucosal lesions includes:  heterotopic gastric mucosa 1-2 mm clustered onl...
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Non-neoplastic solid lesions of the pancreas

Non-neoplastic solid lesions of the pancreas (NNSLP) are conditions which may mimic pancreatic neoplasms on imaging. They include: focal pancreatitis fatty infiltration-replacement intrapancreatic accessory spleen congenital anomalies, such as prominent pancreatic lobulations and bifid pancr...
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Non-specific oesophageal motility disorder

Non-specific oesophageal motility disorder (NSMD) is one of the oesophageal dysmotility disorders. It is used to described patients with oesophageal dysmotility that do not meet diagnostic criteria for other oesophageal motility disorders.  Clinical presentation Patients may be asymptomatic or...
Article

Normal gastrointestinal tract imaging examples

Plain radiograph example 1: abdominal film example 2: erect and supine example 3, example 4: paediatric example 5: young adult example 6: young adult male Barium studies example 1, example 2, example 3: barium swallow example 1: upper GI series example 1: barium follow through example ...
Article

Normal mesenteric lymph nodes

Mesenteric lymph nodes had, during the era of single thick slice CT been only really appreciated when enlarged. With the advent of multidetector volume acquisition CT (and especially coronal reformats) they are commonly seen in normal individual and thus have raised the obvious question of what ...
Article

Normal oesophageal contours on barium swallow

There are a number of normal oesophageal contours or impressions that are encountered when performing a barium swallow. It is important to be able to differentiate normal contours and their variants, as well as contours that may indicate disease. Below is a list of anatomical structures that may...
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Northern exposure sign

The northern exposure sign has been described as a high specificity sign in sigmoid volvulus. On a supine abdominal radiograph, the apex of the sigmoid volvulus is seen above (cranial to) the transverse colon.
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Obstructive jaundice (summary)

Obstructive jaundice represents a set of conditions that cause jaundice by obstructing the flow of bile into the duodenum anywhere along the intrahepatic or extrahepatic biliary tree. Reference article This is a summary article; read more in our article on jaundice. Summary epidemiology dep...
Article

Obturator hernia

Obturator hernias are characterised by bowel herniating between the obturator and the pectineus muscles. They are a rare type of abdominal hernia and can be very difficult to diagnose clinically. Epidemiology Typically obturator hernias occur in elderly women 3,4 or patients with chronically r...
Article

Octreotide scintigraphy

Octreotide scintigraphy uses 111In-labelled octreotide which is a somatostatin analog; it is also known as an OctreoscanTM, a brand name for 111In-labelled pentetreotide; pentetreotide is a DTPA-conjugated form of octreotide, originally manufactured by Mallinckrodt Nuclear Medicine LLC, which no...
Article

Oesophageal atresia

An oesophageal atresia refers to an absence in contiguity of the oesophagus due to an inappropriate division of the primitive foregut into the trachea and oesophagus. This is the most common congenital anomaly of the oesophagus.  Epidemiology It is thought to occur in ~1:3000-4500 live births ...
Article

Oesophageal atresia (classification)

Oesophageal atresia is closely related to tracheo-oesophageal fistula and can be divided into1: type A: isolated oesophageal atresia (8%) type B: proximal fistula with distal atresia (1%) type C: proximal atresia with distal fistula (85%) type D: double fistula with intervening atresia (1%) ...
Article

Oesophageal bronchus

Oesophageal bronchus refers to the rare occurrence where a bronchus arises directly from the oesophagus. Epidemiology It is more common in females with a M:F of 1:2 2.  Gross anatomy Oesophageal bronchi may be the main bronchus, which gives rise to oesophageal lung, or may be a lobar bronchu...
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Oesophageal cancer (staging)

Oesophageal cancer staging can depend slightly on whether the tumour is squamous cell or adenocarcinoma subtype. Due to the lack of a serosal layer, oesophageal cancer often tends to have mediastinal spread at the time of diagnosis. Staging TNM staging T staging Tx: primary tumour cannot be...
Article

Oesophageal cancer (summary)

Oesophageal cancer is a relatively uncommon tumour that occurs within the oesophagus of affected individuals. Patients present with symptoms of increasing dysphagia that progress from solid foods to liquids. Reference article This is a summary article; read more in our article on oesophageal c...
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Oesophageal carcinoma

Oesophageal carcinoma is relatively uncommon. It tends to present with increasing dysphagia, initially to solids and progressing to liquids as the tumour increases in size, obstructing the lumen of the oesophagus. Epidemiology Oesophageal cancer is responsible for <1% of all cancers and 4-10% ...
Article

Oesophageal diverticula

Oesophageal diverticula are sac or pouch projections arising from the oesophagus. Epidemiology They can occur in all ages but more frequent in adults and elderly people. Pathology Oesophageal diverticula are either: true diverticula: include all oesophageal layers false diverticula: contai...
Article

Oesophageal duplication

Duplication of the oesophagus has a range of macroscopic appearances, ranging from complete (which is very rare) to partial cystic duplication (oesophageal duplication cyst). It is the second most common gastrointestinal tract duplication after that of the ileum. Epidemiology A complete duplic...
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Oesophageal duplication cyst

Oesophageal duplication cysts are a type of congenital foregut duplication cyst. Epidemiology Less common compared to other foregut duplication cysts. There may be an increased male predilection 5. Clinical presentation Patients are generally asymptomatic but may complain of dysphagia due to...
Article

Oesophageal dysmotility

Oesophageal dysmotility refers to the pathological disruption of the normal sequential and coordinated muscle motion of the oesophagus to transport food from the oropharynx to the stomach. It is an umbrella term used to refer to the common pathophysiological endpoint of dysmotility that can be c...
Article

Oesophageal fibrovascular polyp

Oesophageal fibrovascular polyps are benign intraluminal submucosal pedunculated tumours that can grow significantly and cause dysphagia symptoms. They usually occur in the upper third of the oesophagus, at the level of the upper oesophageal sphincter.  Terminology They were previously denomin...
Article

Oesophageal food impaction

Oesophageal food impaction (or steakhouse syndrome) refers to a food bolus acutely obstructing the oesophagus. Clinical presentation The main symptom is usually of acute dysphagia. Radiographic features Plain radiograph Depending on the composition of the ingested content, the bolus may be ...
Article

Oesophageal hiatus

The oesophageal hiatus is the opening in the diaphragm through which the oesophagus passes from the thoracic to abdominal cavity. It is one of three apertures in the diaphragm and is located in the right crus. It is situated in the muscular part of the diaphragm at the level of T10 and is ellip...
Article

Oesophageal leiomyoma

Oesophageal leiomyoma is a benign smooth-muscle neoplasm of the oesophagus. It is the most common benign tumour of the oesophagus. Epidemiology It is most frequently presents in young and middle age groups (20-50 years). The overall incidence is around 8-43 per 10,000 autopsy series 4. Clinic...
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Oesophageal leiomyomatosis

Oesophageal leiomyomatosis is rare benign condition. Epidemiology It usually presents at childhood. There is a recognised increased female predilection. Pathology It is considered a hamartomatous condition and is associated with abnormal diffuse proliferation of smooth muscle fibres in dista...
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Oesophageal leiomyosarcoma

Oesophageal leiomyosarcoma is a rare malignant tumour of the oesophagus of smooth muscle origin.  Epidemiology The first case of oesophageal leiomyosarcoma was described in 1905.  Since then, there have been over 164 cases described in the literature. Radiographic features Fluoroscopy - Bari...
Article

Oesophageal mass (mnemonic)

A mnemonic to remember the causes of an oesophageal mass is: CALL the MVP Mnemonic C: carcinoma A: adenoma L: lymphoma L: leiomyoma M: metastasis V: varices P: papilloma/polyp
Article

Oesophageal myotomy

Oesophageal myotomy (or Heller myotomy) is a procedure that can be performed to treat a lower oesophageal sphincter (LES) that fails to relax (e.g. achalasia). The procedure involves a longitudinal incision of the distal oesophageal musculature to break the sphincter tone. A fundoplication wrap...
Article

Oesophageal perforation

Oesophageal perforation is a rare but serious medical emergency with a very high mortality rate, especially if the diagnosis is delayed. Epidemiology Most patients are in their 60s with a slight male predominance 5.  Clinical presentation If a perforation is not detected during the procedure...
Article

Oesophageal pseudodiverticulosis

Oesophageal intramural pseudodiverticulosis is an uncommon condition in which there are numerous small outpouchings within the oesophageal wall. Epidemiology It is a rare condition, found in <1% of oesophagrams. It may occur at any age, but is more common between ages  50 and 70. There is a sl...
Article

Oesophageal squamous papilloma

Oesophageal squamous papilloma is an uncommon finding on oesophagography (barium swallow). It is a benign lesion, but it is difficult to differentiate it from osophageal carcinoma on oesophagography and the diagnosis is usually made with endoscopic biopsy. Clinical presentation Often asymptoma...
Article

Oesophageal stent

Oesophageal stents are a treatment option in patients with oesophageal strictures. It is most commonly used for symptomatic relief in those with dysphagia secondary to malignancy. The stent is typically covered in nature and inserted endoscopically or fluoroscopically. The distal oesophagus is t...
Article

Oesophageal stricture

Oesophageal strictures refer to any persistent intrinsic narrowing of the oesophagus.  Pathology Aetiology The most common causes are fibrosis induced by inflammatory and neoplastic processes. Because radiographic findings are not reliable in differentiating benign from malignant strictures, ...
Article

Oesophageal web

Oesophageal webs refer to an oesophageal constriction caused by a thin mucosal membrane projecting into the lumen. Epidemiology Oesophageal webs tend to affect middle-aged females. Clinical presentation Patients are usually asymptomatic and the finding may be incidental and unimportant. Howe...
Article

Oesophagectomy

Oesophagectomy (or esophagectomy) is a surgical procedure that involves excision of the majority of the oesophagus and part of the proximal stomach, usually as a treatment for oesophageal carcinoma or carcinoma of the gastric cardia, although benign conditions (e.g. stricture) can be treated wit...
Article

Oesophagus

The oesophagus is a muscular tube that conveys food and fluids from the pharynx to the stomach. Gross anatomy The oesophagus is 23-37 cm long with a diameter of 1-2 cm and is divided into three parts: cervical: continuous with the hypopharynx, commences at the lower border of cricoid cartilag...
Article

Omega sign (disambiguation)

The omega sign can refer to a number of different anatomical structures or signs: omega sign (epiglottitis) omega sign (hand bump on the precentral gyrus)
Article

Omental cake

Omental cake refers to infiltration of the omental fat by material of soft-tissue density. The appearances refer to the contiguous omental mass simulating the top of a cake. Masses on the peritoneal surfaces and malignant ascites may also be present.  Pathology The most common cause is metasta...
Article

Omental infarction

Omental infarction is a rare cause of acute abdomen resulting from vascular compromise of the greater omentum. This condition has a non-specific clinical presentation and is usually managed conservatively. The term along with epiploic appendagitis is grouped under the broader umbrella term intra...
Article

Omental torsion

Omental torsion is defined as a twist of the omentum along its long axis with consequent impeding of its vascularity that may mimic acute abdomen 1. Epidemiology Omental torsion is a rare cause of acute abdominal pain that occurs in the third to fifth decade of life with slight male predomina...
Article

Omphalomesenteric fistula

Omphalomesenteric fistula occurs as aresult of failure of obliteration of the omphalomeseneric duct. It is one of the congenital fistulas of gastrointestinal tract . Treatment of choice is often a partial trans umbilical resection with umbilical restitution. See also gut fistulation
Article

Oral cholecystography

Oral cholecystography was a procedure used to image the gallbladder, now largely superseded by ultrasound and MRCP.  It was first described by Graham et. al in 1925, using sodium tetraiodophenolphthalein.  Although rarely performed now, more modern techniques used other cholegraphic agents such...
Article

Order of structures in the porta hepatis (mnemonic)

A useful mnemonic to help remember the order of structures in the porta hepatis from anterior to posterior is: DAVE D: ducts (right and left hepatic duct branches) A: arteries (right and left hepatic artery branches) V: vein (portal vein) E: epiploic foramen (of Winslow)  
Article

Pancreas

The pancreas is a retroperitoneal organ that has both endocrine and exocrine functions: it is involved in the production of hormones (insulin, glucagon and somatostatin), and also involved in digestion by its production and secretion of pancreatic juice. Gross anatomy The pancreas can be divid...

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