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.

1,079 results found
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Juvenile polyposis syndrome

Juvenile polyposis syndrome, also referred as familial juvenile polyposis, is one of the polyposis syndromes and consists of hundreds of juvenile polyps. Epidemiology Presentation in the second decade is most common 2. Clinical presentation Rectal bleeding, bowel obstruction and intussuscept...
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Kikuchi level

The Kikuchi level is a histopathological term used for describing the degree of infiltration of a sessile early invasive colorectal cancer1. Preoperative assessment of the level of invasion using this classification may decrease the incidence of unnecessary surgery for sessile polyps.  Levels o...
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Killian-Jamieson diverticulum

Killian-Jamieson diverticula are oesophageal diverticula. Like the more common Zenker diverticulum, it is a false diverticulum and represents an outpouching of mucosa through a muscular defect, in this case Killian's dehiscence.  Pathology They are located just below the cricopharyngeal muscle...
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Kirklin complex

The Kirklin complex is a combination of the Carman meniscus sign associated with a radiolucent semicircular zone surrounding the elevated ridge of the ulcer. This complex is seen in cases of gastric adenocarcinoma on barium studies. History and etymology Byrl Raymond Kirklin, (1888-1957 2) an ...
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Kirklin sign

The Kirklin sign refers to a deformity of the normal gastric bubble on an upright chest radiograph due to a mass lesion of the gastric cardia or fundus. The differential for a Kirklin sign includes: gastric tumour gastric carcinoma oesophageal carcinoma gastrointestinal stromal tumour (GIST...
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Kommerell diverticulum

Kommerell diverticula occur in some anomalies of the aortic arch system. It usually refers to the bulbous configuration of the origin of an aberrant left subclavian artery in the setting of a right-sided aortic arch. However, it was originally described as a diverticular outpouching at the origi...
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Krenning score of neuroendocrine tumour uptake

The Krenning score is a proposed semi-quantitative method of assessing the degree of tracer uptake on octreotide scintigraphy. Parameters Initially designed for assessment of 111In-DTPA on planar imaging, the Krenning score is applicable to SPECT or SPECT/CT using various radiopharmaceuticals....
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Labelled imaging anatomy cases

This article lists a series of labelled imaging anatomy cases by system and modality. Brain CT head: non-contrast axial CT head: non-contrast coronal CT head: non-contrast sagittal CT head: angiogram axial CT head: angiogram coronal CT head: angiogram sagittal MR head: T2 axial MR head:...
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Ladd bands

Ladd bands are the most commonly encountered form of peritoneal bands in disarrangement of intestines, e.g. intestinal malrotation. Pathology Classically they extend from the abnormally positioned caecum to peritoneum and liver, crossing the duodenum in their course. Extension, however, can in...
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Lane-Hamilton syndrome

Lane-Hamilton syndrome (LHS) refers to the rare concurrent association of idiopathic pulmonary haemosiderosis and coeliac disease 1. Epidemiology It is typically seen in children under the age of 15 but can occasionally be seen in adults. History and etymology It was originally described by ...
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Langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare multi-system disease with a wide and heterogeneous clinical spectrum and variable extent of involvement.  Terminology Langerhans cell histiocytosis was previously known as histiocytosis X. The newer term is preferred as it's more descriptive of its...
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Large bowel lymphoma

Large bowel (colorectal) lymphoma is a very rare tumour, accounting for <0.5% of primary colorectal malignancies, ~1.5% of all lymphomas, and ~15% of gastrointestinal lymphoma. Large bowel lymphoma differs from gastric and small bowel lymphoma in clinical presentation, management and prognosis. ...
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Large bowel obstruction

Large bowel obstruction (LBO) are often impressive on imaging, on account of the ability of the large bowel to massively distend. This condition requires prompt diagnosis and treatment.  Epidemiology Large bowel obstructions are far less common than small bowel obstructions, accounting for onl...
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Large bowel obstruction (summary)

This is a basic article for medical students and other non-radiologists Large bowel obstruction (LBO) occurs when there is mechanical obstruction of the large bowel and is often impressive on imaging on account of the ability of the large bowel to massively distend. This condition requires prom...
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Large intestine

The large intestine (or large bowel) is a 1.5 metre muscular tube that extends from the caecum to the rectum. It has three outer longitudinal muscular layers called taenia coli, which are about 30 cm shorter than the length of the large bowel causing characteristic sacculations interrupted by in...
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Lateral crescent sign (inguinal hernia)

The lateral crescent sign is a useful diagnostic sign of a direct inguinal hernia on CT scan, the hernia causing compression and lateral displacement of the inguinal canal contents (ductus deferens, testicular vessels, fat, etc.) to form a semicircle of tissue that resembles a moon crescent seen...
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Lateral fossa

The lateral fossae are concave depressions of peritoneum in the paravesical space that lie between the lateral umbilical folds and the lateral parietal peritoneum. The lateral fossae are the smallest of the anterior paravesical fossae, and typically partially contain the cecum and/or sigmoid col...
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Lateral umbilical folds

The lateral umbilical folds are raised ridges of parietal peritoneum in the deep aspect of the anterior abdominal wall overlying the inferior epigastric vessels. The paired folds originate medial to the deep inguinal ring and end at the arcuate line on the posterior aspect of the anterior abdomi...
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Lead pipe sign (colon)

The lead pipe appearance of colon is the classical barium enema finding in chronic ulcerative colitis. There is complete loss of haustral markings in the diseased section of colon, and the organ appears smooth-walled and cylindrical. 
Article

Left colic artery

The left colic artery is the first branch of the inferior mesenteric artery. Course It ascends retroperitoneally, dividing into two branches: ascending branch passes anteriorly to the left kidney, then enters the transverse mesocolon, and passes superiorly to supply the upper part of the...
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Left colic flexure

Left colic flexure (or splenic flexure) is the bend in the large intestine in the left upper quadrant of the abdomen as the transverse colon continues as the descending colon. The phrenicocolic ligament attaches the the splenic flexure to the left hemidiaphragm. It lies more cranial than the rig...
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Left gastric artery

The left gastric artery is the smallest and first branch of the coeliac artery.   It passes superiorly, giving off an oesophageal branch to the distal oesophagus, then enters the lesser omentum to pass along the lesser curvature of the stomach.  Anastomoses along the lesser curvature with the r...
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Left gastric vein

The left gastric vein (also known as the coronary vein) drains both gastric walls. It forms a loop with the right gastric vein at the lesser curvature of the stomach. The left gastric vein travels in the lesser omentum to drain in the portal vein. It also communicates with the lower oesophageal ...
Article

Left gastroepiploic artery

The left gastroepiploic artery (LGA) is one of the branches of the splenic artery. Gross Anatomy Course The LGA runs within the two layers of the greater omentum to the right along the greater curvature of the stomach, approximately 1 cm from the gastric wall before it anastomoses with the ri...
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Left perihepatic space

The left perihepatic space (also known as the left subhepatic space) is a potential space located between the stomach and the visceral surface of left lobe of the liver. Gross anatomy The left perihepatic space can be further subdivided into anterior and posterior spaces. It is a subcompartmen...
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Left subphrenic space

The left subphrenic space is a subcompartment of the left supramesocolic space located between the diaphragm and the superior surface of the left lobe of liver. It is described to have anterior and posterior parts without clear delineation1. Boundaries  medially: falciform ligament posterior...
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Left supramesocolic space

The left supramesocolic space is an arbitrary subdivision of the supramesocolic space, which lies between the diaphragm and the transverse colon 1,2. Gross anatomy The left supramesocolic space is separated from the right supramesocolic space by the falciform ligament 3. The left supramesocoli...
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Leiomyosarcoma

Leiomyosarcomas (LMS) are extremely rare malignant neoplasms that originate from smooth muscle cells and may be considered the malignant counterpart of a leiomyoma. They are classified as a soft tissue tumour and account for ~8% of malignant soft tissue tumours 10. Pathology Location  Leiomyo...
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Lemmel syndrome

Lemmel syndrome is defined as an obstructive jaundice caused by a periampullary duodenal diverticulum (of the second part of the duodenum) compressing the intrapancreatic part of the common bile duct with resultant upstream dilatation of the extra- and intrahepatic bile ducts. Clinical presenta...
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Lesser sac

The lesser sac or omental bursa is a potential peritoneal space within abdomen, part of the peritoneal cavity. It may be conceptualized as the space posterior to the lesser omentum, between the posterior wall of the stomach and surface of peritoneum which covers the anterior surface of the left ...
Article

Lesser sac hernia

Lesser sac hernias are a type of internal hernia, where abdominal contents protrude through the foramen of Winslow, hence they are also known as foramen of Winslow hernia.  Epidemiology Lesser sac hernias are rare, accounting for <0.1% of abdominal hernias and 8% of internal hernias 1,2. Path...
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Levator ani

The levator ani, also known as the muscular pelvic diaphragm, is the musculotendinous sheet that forms the majority of the pelvic floor, supports the pelvic viscera, and aids in urinary and faecal evacuation as well as maintaining continence. Gross anatomy The levator ani has three main compon...
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Levator ani syndrome

Levator ani syndrome (LAS) is a musculoskeletal pain syndrome involving the pelvic floor, thought to be caused by spasm or scarring of the levator ani muscles. Clinical presentation Levator ani syndrome is characterised by recurrent pain, pressure or discomfort in the region of the rectum, sac...
Article

Li-Fraumeni syndrome

Li-Fraumeni syndrome is a hereditary cancer syndrome due to mutations in the tumour suppressor gene TP53. Approximately half of affected individuals are thought to develop invasive cancer by 30 years of age 1. Associated malignancies sarcomas osteosarcoma rhabdomyosarcoma CNS tumours gliom...
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Ligament of Treitz

The ligament of Treitz, also known as the suspensory ligament of the duodenum, is a double fold of peritoneum suspending the duodenojejunal flexure from the retroperitoneum. It is often used interchangeably with duodenojejunal (DF) flexure. Anatomy The ligament of Treitz is comprised of two p...
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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...
Article

Light bulb sign (phaeochromocytoma)

The light bulb sign of an adrenal phaeochromocytoma is MRI feature of this tumour. This refers to marked hyperintensity seen on T2 weighted sequences however this finding is neither sensitive nor specific and phaeochromocytomas are more often heterogeneous with intermediate or high T2 signal int...
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Linea alba

The line alba (Latin for white line) is a single midline fibrous line in the anterior abdominal wall formed by the median fusion of the layers of the rectus sheath medial to the bilateral rectus abdominis muscles. It attaches to the xiphoid process of the sternum and the pubic symphysis. The umb...
Article

Linitis plastica

Linitis plastica is a descriptive term usually referring to the appearance of the stomach, although the rectum can also be described this way. The appearance is said to be reminiscent of an old leather water-bottle. Pathology The underlying cause is usually a scirrhous adenocarcinoma with diff...
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Lipase

Lipase, more specifically pancreatic lipase, is an enzyme produced in the pancreas and is responsible for the digestion of fat molecules. It may be raised (hyperlipasaemia) in numerous pancreatic, hepatobiliary and other diseases but is most commonly associated with acute pancreatitis. Physiolo...
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Lipoma

Lipomas are benign tumours composed of mature adipocytes. They are the most common soft tissue tumour, seen in ~2% of the population.  Epidemiology Patients typically present in adulthood (5th-7th decades). Clinical presentation Typically lipomas are subcutaneous in location and present in a...
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Lipomatosis

Lipomatosis is a condition where there is diffuse excessive fat deposition within the body. This can especially affect certain regions. neck and upper region of trunk Madelung disease mediastinal lipomatosis heart lipomatous hypertrophy of the interatrial septum lipomatous metaplasia of th...
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Lipomatosis of the ileocaecal valve

Lipomatosis of the ileocaecal valve is a benign condition usually detected incidentally during investigation of other conditions. However, it may itself cause certain vague abdominal symptoms and may be missed on preliminary ultrasound unless a high level of suspicion is present. Epidemiology ...
Article

Liposarcoma

Liposarcomas are malignant tumours of fatty tissue and are the malignant counterpart to a benign lipoma. They are the second commonest type of soft-tissue sarcoma. Epidemiology Liposarcomas are typically found in adults, typically between the ages of 40 and 60, and are rare in children. Clini...
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Littoral cell angioma of the spleen

Littoral cell angioma of the spleen (LCA) is a rare and relatively recently (1991) described vascular tumour of the spleen. Epidemiology Littoral cell angiomas may occur at any age and have no gender predilection. Clinical presentation Typically, patients with littoral cell angioma are found...
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Littre hernia

Littre hernia is a hernia containing a Meckel's diverticulum. Also known as a persistent omphalomesenteric duct hernia. It is most frequently encountered in the inguinal region. Radiographic features CT blind ending tubular structure arising from antimesentric border of small bowel and extend...
Article

Liver

The liver is the largest abdominal organ that plays a major role in metabolism and has a number of functions, including glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, and detoxification. It is one of the very few organs that has the ability to r...
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Liver overlap sign

The liver overlap sign can be seen in sigmoid volvulus wherein the sigmoid loop is seen, usually on an abdominal radiograph, ascending to the right upper quadrant and projecting over the liver shadow. In one study of 21 patients with confirmed sigmoid volvulus, the sign was present in 9 patient...
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Loop-to-loop colon

The loop-to-loop colon describes an abnormal colonic course associated with the absence of the left kidney from the renal fossa.  The transverse colon extends to the lateral margin of the abdominal wall and the descending colon courses medially to fill the renal fossa, resulting in a "looped" c...
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Low attenuation lymphadenopathy

Low attenuation lymphadenopathy suggests underlying necrosis and can be seen in: metastatic carcinoma (or lymphoma) infections (tuberculous or fungal) Whipple disease coeliac sprue inflammatory necrotic disorders (e.g. Kikuchi-Fujimoto disease) See also lymphadenopathy low attenuation ly...
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Lower abdominal / pelvic calcification

Causes of calcifications in the lower abdomen and pelvis include: vascular calcifications artherosclerosis aneurysms phleboliths urogenital uterine fibroid prostatic calcification seminal vesicle and ductus deferens calcification bladder stones gallstones dropped stones following chol...
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Lower gastrointestinal bleeding

Lower gastrointestinal bleeding (LGIB) is defined as that occurring distal to the ligament of Treitz (i.e. from the jejunum, ileum, colon, rectum or anus) and presenting as either haematochezia (bright red blood/clots or burgundy stools) or melaena. Epidemiology The incidence of lower gastroin...
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Lower gastrointestinal bleeding (differential)

Lower gastrointestinal bleeding usually occurs distal to the ligament of Treitz, and has a wide differential diagnosis: diverticular disease enterocolitis infective Crohn’s disease ulcerative colitis ischaemic colitis vascular malformation vascular ectasia angiodysplasia arteriovenous ...
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Low-grade appendiceal mucinous neoplasm

Low-grade appendiceal mucinous neoplasms (LAMN), previously known as appendiceal mucinous cystadenomas, are rare mucinous tumours of the appendix showing low-grade cytologic atypia, c.f. high-grade appendiceal mucinous neoplasms. Terminology  Considerable controversy still exists on mucinous n...
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Lucent liver sign

The lucent liver sign is represented by a reduction of hepatic radiodensity on supine radiograph when there is a collection of free intraperitoneal gas located anterior to the liver.
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Lumbar hernia

Lumbar hernias are a rare form of posterior abdominal hernia.  Epidemiology Most common in patients aged between 50 and 70 years with a male predominance 1.  Clinical presentation Patients with lumbar hernias can present with a variety of symptoms, including a posterolateral mass, back pain,...
Article

Lymphocele of the thoracic duct

Introduction Lymphocele of the thoracic duct (thoracic duct cyst) is usually asymptomatic or less commonly may present as  left supraclavicular fossa mass 1. The clinical significance of a thoracic duct cyst lies in its misidentification as a pathological lesion at radiological assessment, whi...
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Macroamylasaemia

Macroamylasaemia is the presence of serum amylase of a large molecular size, seen in both otherwise healthy individuals, and also in various diseases. Amylase seems to be able to self-polymerise and/or form complexes with other blood proteins, e.g. immunoglobulins. Epidemiology Macroamylasaemi...
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Macrolipasaemia

Macrolipasaemia is the presence of serum lipase of a large molecular size, seen occasionally in otherwise healthy individuals, but more commonly in various diseases. Lipase is able to self-polymerise and/or form complexes with other blood proteins e.g. immunoglobulins. Epidemiology Epidemiolog...
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Magenstrasse

The term magenstrasse refers to a tubular portion of the stomach adjacent to the lesser curve of the stomach. It is a favoured route by food, fluids and drugs as they flow from the cardia/fundus to the gastric outlet 1. Magenstrasse is an old German anatomical term that has come back into commo...
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Magnetic resonance cholangiopancreatography

Magnetic resonance cholangiopancreatography (MRCP) is a non-invasive imaging technique to visualize intra and extrahepatic biliary tree and pancreatic ductal system. It can provide the diagnostic range equivalent to the ERCP and so it can replace the ERCP in high risk patient to avoid significa...
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Malignant biliary tract obstruction (summary)

This is a basic article for medical students and other non-radiologists Malignant biliary tract obstruction (MBTO) represents a group of conditions that cause obstructive jaundice. While most examples are the result of pancreatic head cancers, other malignancies may be causative. Reference art...
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Malignant oesophageal neoplasms

Malignant oesophageal neoplasms are much more common than benign oesophageal neoplasms, especially if the patient is symptomatic.  Pathology oesophageal carcinoma (90%) oesophageal squamous cell carcinoma (SCC) oesophageal spindle cell carcinoma oesophageal adenocarcinoma oesophageal neuro...
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Malignant vs benign gastric ulcer (barium)

Barium meal has been frequently used to differentiate malignant and benign gastric ulcers: Features suggesting benign gastric ulcer outpouching of ulcer crater beyond the gastric contour (exoluminal) smooth rounded and deep ulcer crater smooth ulcer mound smooth gastric folds that reach the...
Article

Mallory-Weiss tear

Mallory-Weiss tears occur due to violent projection of gastric contents against the lower oesophagus, which results in mucosal and submucosal tear with involvement of the venous plexus. The resultant clinical syndrome is known as Mallory-Weiss syndrome.  Clinical presentation Patients present ...
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Malone antegrade continence enema procedure

Malone antegrade continence enema is a surgical procedure where the vermiform appendix or ‘neoappendix’ is used to create a small stoma at the abdominal wall allowing antegrade enemas to be administered to empty the colorectum. This procedure is important particularly in children and adolescents...
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Marginal artery of Drummond

The marginal artery of Drummond, also known as the marginal artery of the colon, is a continuous arterial circle or arcade along the inner border of the colon formed by the anastomoses of the terminal branches of the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA). Gross a...
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Marginal artery of Drummond and arc of Riolan (mnemonic)

Remembering the colon vascular supply can be confusing because of inconstant collateral vascularisation, therefore mnemonics can be helpful. One way to remember the location of the marginal artery of Drummond is to remember that it runs distally to the root of the mesentery (near the colon). I...
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Mass of the inguinal region (differential)

The differential diagnosis of a mass in the inguinal region includes: inguinal hernia femoral hernia hydrocele of the canal of Nuck lymphadenopathy or necrotic lymph node aneurysm or pseudoaneurysm of the femoral artery iliopectineal bursa abscess haematoma lymphangioma epidermal inclu...
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Maydl hernia

Maydl hernias are defined as the presence of two small bowel loops within a single hernial sac, that is, there are two efferent and two afferent loops of bowel, forming a "W" shape. This type of hernia is more prone to strangulation and necrosis. The intervening intra-abdominal loop is also at ...
Article

McBurney point

McBurney point is defined as a point that lies one-third of the distance laterally on a line drawn from the umbilicus to the right anterior superior iliac spine. Classically, it corresponds to the location of the base of the appendix 1. Clinically, McBurney point is relevant for the elicitation...
Article

McKeown procedure

The McKeown procedure ("tri-incisional oesophagectomy") is a type of oesophagectomy, that is similar in concept to an Ivor Lewis procedure, but it tends to be used for oesophageal lesions that are higher in the oesophagus. Procedure laparotomy stomach mobilized, the oesophagus "gastric tube"...
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Meandering main pancreatic duct

Meandering main pancreatic duct (MMPD) comprises of a reverse Z-type and loop-type of pancreatic ducts. These ductal variants are found in ERCP and MRCP studies. The exact incidence is not known. Increased incidence of meandering pancreatic duct has been reported in patients with idiopathic re...
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Meckel diverticulitis

Meckel diverticulitis is the inflammation of Meckel diverticulum, which is the most common congenital structural abnormality of the gastrointestinal tract 3. Despite this, it is an uncommon cause of acute abdomen and is often not correctly diagnosed pre-operatively.  This article focuses on Mec...
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Meckel diverticulum

Meckel diverticulum is a congenital intestinal diverticulum due to fibrous degeneration of the umbilical end of the omphalomesenteric (vitelline) duct that occurs around the distal ileum. It is considered the most common structural congenital anomaly of the gastrointestinal tract. Epidemiology ...
Article

Meconium ileus

Meconium ileus refers to a neonatal bowel obstruction of the distal ileum due to abnormally thick and impacted meconium. Unlike in the meconium plug syndrome, the meconium is abnormal in consistency. Epidemiology Meconium ileus is more common in white populations and affects both sexes almost ...
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...
Article

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...
Article

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...
Article

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 ...
Article

Mediastinal pseudocyst

A mediastinal pseudocyst is the extension of pancreatic pseudocyst into the posterior mediastinum through oesophageal or aortic hiatus or rarely through the foramen of Morgagni. It is a rare complication of acute or chronic pancreatitis. Clinical presentation It can present with symptoms due t...
Article

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...
Article

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...
Article

Melioidosis

Melioidosis is an infectious disease caused by Burkholderia pseudomallei (previously known as Pseudomonas pseudomallei) and is a multisystem disorder which may affect the lungs, brain, visceral organs, or musculoskeletal system. Epidemiology Melioidosis is a disease of the monsoon season in th...
Article

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...
Article

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...
Article

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, although...
Article

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 mesentery, the masses may occur...
Article

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...
Article

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...
Article

Mesorectal fascia

The mesorectal fascia is a layer of connective tissue enclosing the peri-rectal fat that surrounds the rectum. It is an important anatomical structure in rectal cancer staging. Summary location: envelopes the peri-rectal fat which surrounds the rectum within the pelvis boundaries: extends fro...
Article

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 a changed cellular environment to which the new cell type is better adapted 1. Examples include 2-5: Barrett oesophagus: normal squamous epithelium replac...

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