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.

935 results found
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4D syndrome

4D syndrome is a term given to syndromic glucagonomas, a type of pancreatic endocrine tumour. D: dermatitis (necrolytic migratory erythema, often involving the groin) D: diabetes D: deep vein thrombosis D: depression
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AAST injury scoring scales

The American Association for the Surgery of Trauma (AAST) injury scoring scales are the most widely accepted and used system of classifying and categorising traumatic injuries. Injury grade reflects severity, guides management, and aids in prognosis. At the time of writing (mid 2016), 32 differe...
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AAST spleen injury scale

The 1994 revision of the American Association for the Surgery of Trauma (AAST) splenic injury scale is the most widely used grading system for splenic trauma at the time of writing (late 2016).  Classification grade I subcapsular haematoma <10% of surface area capsular laceration <1 cm depth...
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Abdomen (AP supine view)

AP supine radiograph can be performed as a standalone projection or as part of an acute abdominal series, depending on the clinical question posed, local protocol and the availability of other imaging modalities. Patient position the patient is supine, lying on their back, either on the X-ray ...
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Abdomen (lateral decubitus view)

The lateral decubitus abdominal radiograph is used to identify free intraperitoneal gas (pneumoperitoneum). It can be performed when the patient is unable to be transferred to, or other imaging modalities (e.g. CT) are not available. The most useful position for detecting free intraperitoneal ai...
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Abdomen (PA erect view)

The PA erect abdominal radiograph is often obtained in conjunction with the AP supine abdominal view in the acute abdominal series of radiographs. When used together it is a valuable projection in assessing air fluid levels, and free air in the abdominal cavity. The erect abdominal radiograph h...
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Abdominal adhesions

Abdominal adhesions are bands of scar tissue (fibrous or fibrous fatty), most often occurring as a complication of previous abdominal surgery. Pathology Adhesions often occur with multiple abdominal operations or previous postoperative intra-abdominal complications history of intra-abdominal i...
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Abdominal cavity

The abdominal cavity is divided into two major compartments, the peritoneum and retroperitoneum, early in fetal development. The parietal peritoneum is reflected over the peritoneal organs to form a series of supporting peritoneal ligaments, mesenteries and omenta. The peritoneal reflections ca...
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Abdominal hernia

Abdominal hernias (herniae also used) may be congenital or acquired and come with varying eponyms. They are distinguished primarily based on location and content. 75-80% of all hernias are inguinal. Content of the hernia is variable, and may include: small bowel loops mobile colon segments (s...
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Abdominal (lateral view)

The lateral view abdominal radiograph is a useful problem-solving view that can complement frontal views of the abdomen, often utilised in the context of forging dies or to better visualise lines such as a shunt. It is different than the lateral decubitus view of the abdomen and looks more like ...
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Abdominal opacities

An opacity projecting over the abdomen has a broad differential. Possibilities to consider include: foreign bodies ingested, e.g. coins, batteries, bones, etc artifacts, e.g. object attached to the cloth of the patient like a safety pin or button iatrogenic, e.g. haemostatic clips, gastric b...
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Abdominal organ echogenicity (mnemonic)

This mnemonic helps to remember the relative echogenicity of abdominal organs on ultrasound: Darling Parents So Love Kids Mnemonic From most to least echogenic: D: diaphragm P: pancreas S: spleen L: liver K: kidneys (cortex)
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Abdominal paracentesis

Abdominal paracentesis, more commonly referred to as an ascitic tap, is a procedure that can be performed to collect peritoneal fluid for analysis or as a therapeutic intervention. Indications diagnostic: especially for newly diagnosed ascites determine aetiology of ascites assess for bacter...
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Abdominal radiograph (AP supine view neonatal)

AP supine radiograph for neonates is a mobile examination performed on the neonatal unit. It can be taken as a standalone projection or as part of a series including a left lateral decubitus x-ray in cases of suspected perforation.  Patient position the patient is supine, lying on their back i...
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Abdominal radiography

Abdominal radiography can be useful in many settings. Before the advent of computed tomography (CT) imaging, it was a primary means of investigating gastrointestinal pathology and often allowed indirect evaluation of other abdominal viscera. Indications Although abdominal radiography has lower...
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Abdominal radiology: conditions (curriculum)

Abdominal radiology conditions are a broad group of heterogeneous conditions that are split into: true pathology (e.g. colonic carcinoma) the underlying process (e.g. large bowel obstruction) It is important to have an overview of these conditions and understand what imaging is useful in thei...
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Abdominal radiology for students (curriculum)

Abdominal radiology curriculum for medical students is broadly split into content that refers to imaging (the test and findings) and conditions that are considered key for this stage of training. Some non-abdominal conditions are included in this portion of the curriculum, including breast dise...
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Abdominal radiology: imaging (curriculum)

Imaging in general surgery is vital to ensure timely and accurate diagnosis for patients.  You need to know the gamut of tests that are available when to use the correct test, some important findings that commonly occur and (for some investigations) how to approach looking at the images that ar...
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Abdominal radiology: interpretation (curriculum)

Abdominal radiology interpretation is a key component of how to make the most of diagnostic imaging. You need to know how to look at the commonly performed radiology tests and how to make common diagnoses.
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Abdominal radiology: key findings (curriculum)

Abdominal radiology key findings are a group of imaging findings that are really important in imaging of the abdomen. They point to disease processes and help to narrow the differential diagnosis. It is important to know these and recognise them on imaging.
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Abdominal radiology: presentations (curriculum)

Abdominal radiology presentations are a relatively distinct group of presentations that precipitate assessment medical and surgical teams.
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Abdominal radiology: tests and when to use them (curriculum)

Abdominal radiology tests and when to use them are a set of articles that help to outline the common tests that may be used in radiology and what they are useful for. Plain films (erect chest and supine abdomen), as well as ultrasound and CT abdomen, will be the bread and butter of the imaging ...
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Abdominal surface anatomy

The abdomen, when looking from in front, is divided into nine regions by imaginary planes (two vertical and two horizontal) forming abdominal surface anatomy. The nine regions are of clinical importance when examining and describing pathologies related to the abdomen. The horizontal planes are o...
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Abdominal trauma

Abdominal trauma is usually divided into blunt and penetrating trauma. Findings of abdominal trauma haemoperitoneum splenic trauma: most common hepatic trauma renal trauma pancreatic trauma gastrointestinal tract (bowel) trauma: proximal jejunum is most commonly affected by blunt trauma,...
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Abdominal x-ray - an approach (summary)

Abdominal radiographs can be challenging examinations to look at. It is always best to approach radiographs in a systematic way. Bowel gas pattern Gas within the bowel forms a natural contrast with surrounding tissues since it has a very low density. Bowel can only be seen if it contains air/g...
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Abdominal x-ray (summary)

Abdominal radiographs can be a useful examination, but you need to think about the question you are asking before getting the test. Before the advent of computerised tomography (CT) imaging, it was a primary means of investigating gastrointestinal pathology (and often allowed indirect evaluation...
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Abnormal bowel wall attenuation patterns

Abnormal bowel wall attenuation patterns on CT scan can be grouped under five categories: white enhancement gray enhancement water halo sign fat halo sign black attenuation The first three patterns are seen on contrast studies. White enhancement It is defined as uniform enhancement of th...
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Abnormal collection of barium anywhere (mnemonic)

A mnemonic used for abnormal collection of barium anywhere in the body : FEDUP Mnemonic F: fistula E: extravasation D: diverticulum U: ulcer P: perforation
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Abnormal intra-abdominal gas

Abnormal intra-abdominal gas is an important radiologic finding with many potential causes. It may be seen on a chest radiograph, abdominal radiograph, CT or MRI. pneumoperitoneum retropneumoperitoneum pseudopneumoperitoneum abnormally located bowel, e.g. Chilaiditi syndrome (bowel interpose...
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Abscess

Abscesses are focal confined collections of suppurative inflammatory material and can be thought of as having three components 1: a central core consisting of necrotic inflammatory cells and local tissue peripheral halo of viable neutrophils surrounded by a 'capsule' with dilated blood vessel...
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Accessory appendicular artery

The accessory appendicular artery (or artery of Seshachalam) is a branch of the posterior caecal artery, which in turn arises from the ileocolic artery, and runs in the mesoappendix. The exact prevalence of this accessory artery and its impact upon the risk of appendicitis varies among studies....
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Accessory parotid glands

Accessory parotid glands are a normal variant and represent ectopic salivary tissue separate from, but usually in close proximity to, the main parotid glands 1. Occasionally the accessory tissue is contiguous with the main glands. Epidemiology Accessory parotid glands are commonly picked up in...
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Accordion sign (colon)

The accordion sign is seen on CT examinations of the abdomen and refers to the similarity between the thickened oedematous wall of pseudomembranous colitis and the folds of an accordion. This appearance is the result of oral contrast being trapped between oedematous haustral folds and pseudomemb...
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Achalasia

Achalasia (primary achalasia) refers to a failure of organised oesophageal peristalsis with an impaired relaxation of the lower oesophageal sphincter (LOS), resulting in often marked dilatation of the oesophagus and food stasis. Obstruction of the distal oesophagus (often due to tumour) has been...
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Acute abdominal series

The acute abdominal series is a common set of abdominal radiographs obtained to evaluate bowel gas.  Indications The acute series is used for a variety of indications including:  determine the amount of bowel gas, with possible bowel distention assess air-fluid levels query pneumoperitoneum...
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Acute cholecystitis (summary)

Acute cholecystitis refers to the acute inflammation of the gallbladder. It is the primary complication of cholelithiasis and the most common cause of acute pain in the right upper quadrant (RUQ). Reference article This is a summary article; read more in our article on acute cholecystitis. Su...
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Acute gastritis

Acute gastritis is a broad term that encompasses a myriad of causes of gastric mucosal inflammation. Epidemiology  Depends on the aetiology (see below). Clinical presentation asymptomatic epigastric pain/tenderness nausea and vomiting loss of appetite Pathology Aetiology infection: H. ...
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Acute necrotic collection

Acute necrotic collections (ANCs) are an early, local complication of necrotising pancreatitis. Terminology The following are the latest terms according to the updated Atlanta classification to describe fluid collections associated with acute pancreatitis 1,2: fluid collections in interstitia...
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Acute pancreatitis

Acute pancreatitis is an acute inflammation of the pancreas and is a potentially life-threatening condition. The diagnosis of acute pancreatitis is made by fulfilling two of the following three criteria 8: acute onset of persistent, severe epigastric pain (i.e. pain consistent with acute pancr...
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Acute pancreatitis (summary)

Acute pancreatitis refers to acute inflammation of the pancreas and is a potentially life-threatening condition. Reference article This is a summary article; read more in our article on acute pancreatitis. Summary anatomy pancreas epidemiology epidemiology is dependent on the cause of pa...
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Acute peripancreatic fluid collection

Acute peripancreatic fluid collections (APFC) are an early complication of acute pancreatitis that usually develop in the first four weeks. After four weeks, the term pseudocysts is used. The absence of necrosis differentiates APFCs from acute necrotic collections (ANC), that is, APFCs occur in ...
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Acute superior mesenteric artery occlusion

Acute superior mesenteric artery occlusion, which can then result in an acute mesenteric ischaemia, can be a life-threatening event related to the artery supplying the majority of the small bowel and right side of the colon.  Epidemiology  An acute occlusion is an uncommon event that typically...
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Acute superior mesenteric vein thrombosis

Acute superior mesenteric vein thrombosis is one of the less common causes of intestinal ischaemia. For a general discussion refer to intestinal ischaemia.  Epidemiology Compared to acute superior mesenteric artery occlusion or ischaemia secondary to small bowel obstruction, acute superior me...
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Adenocarcinoma of the appendix

Adenocarcinoma of the appendix, also referred to as nonmucinous adenocarcinoma of the appendix, is an uncommon type of appendiceal epithelial neoplasm. Different from the appendiceal mucinous neoplasms, these tumours share similar epidemiology and pathology with colorectal adenocarcinoma. Epide...
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Adenocarcinoma of the duodenum

Duodenal adenocarcinoma is the most common primary malignancy of the duodenum. Epidemiology Adenocarcinoma is the most common primary malignant neoplasm of the duodenum. It represents 0.3% of all gastrointestinal malignancies and accounts for  50-70% of small bowel adenocarcinomas occurring ei...
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Adenocarcinoma of the small bowel

Primary adenocarcinoma of the small bowel is about 50 times less common than colonic carcinoma. Pathology Almost 50% of small bowel adenocarcinomas are found in the duodenum, especially near the ampulla. In the remaining cases, the jejunum is more commonly involved than the ileum1. Risk facto...
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Adenomyomatosis of the gallbladder

Adenomyomatosis of the gallbladder is a hyperplastic cholecystosis of the gallbladder wall. It is a relatively common and benign cause of diffuse or focal gallbladder wall thickening. It is most easily seen on ultrasound and MRI.  Epidemiology Adenomyomatosis is relatively common, found in ~9%...
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Adrenal metastases

Adrenal metastases are the most common malignant lesions involving the adrenal gland. Metastases are usually bilateral but may also be unilateral. Unilateral involvement is more prevalent on the left side (ratio of 1.5:1). Epidemiology They are present at autopsy in up to 27% of patients with ...
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Adrenal washout

Adrenal washout can be calculated using the density value of an adrenal mass on non-enhanced, portal venous phase and 15 minutes delayed CT-scans. It is primarily used to diagnose adrenal adenoma. absolute washout [(HUportal venous phase) - (HUdelayed)] / [(HUportal venous phase) - (HUnon-enha...
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Adynamic ileus

Adynamic ileus is the failure of passage of enteric contents through the small bowel and colon that are not mechanically obstructed. Essentially it represents the paralysis of intestinal motility. Clinical presentation Patients may be asymptomatic or present with symptoms similar to a mechanic...
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Afferent loop syndrome

Afferent loop syndrome is an intermittent partial or complete mechanical obstruction of the afferent limb of a gastrojejunostomy. The syndrome classically refers to obstruction of the upstream limb of a side-to-side gastrojejunostomy, but has also been used to refer to the biliopancreatic limb ...
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AFP elevation

Human alpha fetoprotein (AFP) elevation may occur in a vast number of conditions: liver tumours (hepatocellular carcinoma, hepatoblastoma) <10 ng/ml is within normal limits >20 ng/ml is above normal limits but has low specificity for tumor since it may occur in a setting of diffuse liver inju...
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AIDS defining illness

AIDS defining illnesses are conditions that in the setting of a HIV infection confirm the diagnosis of AIDS, and do not commonly occur in immunocompetent individuals 2. According to the CDC surveillance case definition 1, they are: Infectious bacterial infections: multiple or recurrent candid...
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Allgrove syndrome

Allgrove syndrome (also known as triple A syndrome) is an autosomal recessive condition that consists of three main findings: achalasia alacrima ACTH insensitivity
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Alvarado score

The Alvarado score is a clinical decision rule and predictor of the likelihood of acute appendicitis: right lower quadrant tenderness (+2) elevated temperature (37.3°C or 99.1°F) (+1) rebound tenderness (+1) migration of pain to the right lower quadrant (+1) anorexia (+1) nausea or vomitin...
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Amoebic colitis

Amoebic colitis is a type of infectious colitis, more common in tropical and subtropical areas. The causative agent is the trophozoite form of the protozoan Entamoeba histolytica. In most cases of transmission, the cyst form lives in the colon as commensal and remains asymptomatic. Clinical pre...
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Ampulla of Vater

The ampulla of Vater is a conical structure at the confluence of the common bile duct (CBD) and the main pancreatic duct that protrudes at the major duodenal papilla into the medial aspect of the descending duodenum. The entire structure is encased by smooth muscle fibers that compose the sphinc...
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Ampullary tumour

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

The Amsterdam criteria are used in the diagnosis hereditary non polyposis colorectal cancer (HNPCC). Amsterdam Criteria I Initial description in 1991: > or equal to 3 relatives with colorectal cancer (CRC) > or equal to 1 case in a first degree relative > or equal to 2 successive generation...
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Amyand hernia

Amyand hernia is a rare form of inguinal hernia in which the vermiform appendix is located within the hernial sac. It is seen in less than 1% of inguinal hernia. It should not be confused with an appendix-containing femoral hernia, known as De Garengeot hernia. Clinical presentation Clinicall...
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Anal atresia

Anal atresia, or imperforate anus, refers to a spectrum of anorectal abnormalities ranging from a membranous separation to complete absence of the anus. Epidemiology The estimated incidence is 1 in 5000 live births. Pathology Clinically there is no anal opening. Subtypes can be classified in...
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Anal canal

The anal canal is the terminal part of the gastrointestinal tract. Anatomically, the anal canal is referred to as the terminal alimentary tract between the dentate line and anal verge. However, histologically it extends more proximally and includes the columns of Morgagni and anal sinuses. Surgi...
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Anal canal cancer protocol (MRI)

Anal canal cancer is relativity rare, however, there are several protocols that exist for assessment of various pelvic pathology. One method adopted for optimum assessment for anal cancer is (Auckland-New Zealand) Overview: whole pelvis T1 +/- T2FS Fine 3 mm slices through region of concern (...
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Anal canal fistula assessment (MRI)

MR of the pelvis can demonstrate hidden areas of pelvic infection and secondary extensions which are important to detect prior to the sugary to minimize high rate of recurrence post intervention. Also pelvic MRI assists to delineate the anatomic relationships of the fistula to sphincters which c...
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Anal cancer

Anal cancer is a relatively uncommon malignancy. It accounts for less than 2% of large bowel malignancies and 1-6% of anorectal tumours (~1.5% of all gastrointestinal tract malignancies in the United States 14).  Epidemiology There may be a slight male predilection where its incidence has been...
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Anal cancer (staging)

The accepted TNM staging of anal cancer is as follows 1: Primary tumour (T) TX: primary tumour cannot be assessed T0: no evidence of primary tumour Tis: carcinoma in situ T1: tumour 2 cm or less in greatest dimension T2: tumour >2 cm but <5 cm in greatest dimension T3: tumour >5 cm in gre...
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Anal margin

Anal margin or perianal skin is arbitrarily defined as a skin tissue with a radius of 5 cm from the anal verge, consisting of keratinizing squamous epithelial tissue containing hair follicles. See also anal margin neoplasms
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Anal sphincter

The anal sphincter is divided into an internal and external anal sphincter. It surrounds the anal canal.  Gross anatomy Internal anal sphincter continuation of inner rectal muscle thickened, circular muscle fibres, up to 5 mm thick composed of visceral muscle External anal sphincter Compo...
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Anal verge

Anal verge is part of anal region and consists of a band of squamous epithelial tissue lacks hair follicles and extends from inter-sphincteric groove to perianal skin. 
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Anatomy curriculum

The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists. General anatomy Neuroanatomy Head and neck anatomy Thoracic anatomy Abdominal and pelvic anatomy Spinal anat...
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Angiosarcoma of the spleen

An angiosarcoma of the spleen is a rare malignant splenic neoplasm. The term is usually given to describe a primary angiosarcoma of the spleen although angiosarcoma elsewhere can also rarely metastasise to the spleen.  Despite its absolute rarity, a splenic angiosarcoma is considered the most co...
Article

Annular pancreas

Annular pancreas is a morphological anomaly which can cause duodenal obstruction. This condition is important to recognise, as radiologists are frequently the first to make the diagnosis. Epidemiology The incidence is probably 1 in 250, however incidence is not accurately reported 1. It is as ...
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Anorectal disease (summary)

Anorectal disease is a group of conditions that affect the anus and rectum. The most common conditions in this group include haemorrhoids, anal fissures, anorectal abscess and anal fistula. Reference article This is a summary article; we do not have a more in-depth reference article. Summary ...
Article

Anterior pararenal space

The anterior pararenal space is the portion of the retroperitoneum that lies between the posterior surface of the parietal peritoneum and the anterior reflection of the perirenal fascia. Gross anatomy It contains the duodenum, pancreas and retroperitoneal segments of the ascending and descendi...
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Antibiotic-associated diarrhoea

Antibiotic-associated diarrhoea can be broadly divided into two groups: Clostridium difficile colitis non-specific diarrhoea The former is a life-threatening condition, requiring prompt diagnosis and treatment whereas the later is milder and self-limiting.  Both result from changes in the bo...
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Antral nipple sign

The antral nipple sign refers to redundant pyloric mucosa protruding into the gastric antrum and is seen in pyloric stenosis. See also cervix sign of pyloric stenosis target sign of pyloric stenosis shoulder sign of pyloric stenosis
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Antral pad sign

The antral pad sign is a feature seen on a spot radiograph of the upper gastrointestinal tract obtained with orally-administered contrast material. It refers to the extrinsic impression or indentation on the posteroinferior aspect of the antrum. The impression is generally arcuate and smooth, an...
Article

Aortic hiatus

The aortic hiatus is one the three major apertures through the diaphragm and lies at the level of T12. Strictly speaking, it is not a real aperture in the diaphragm, but an osseoaponeurotic opening between it and the vertebral column.  The hiatus is situated slightly to the left of the midline ...
Article

Aortoenteric fistula

Aortoenteric fistula is an uncommon catastrophic cause of gastrointestinal haemorrhage. Aortic fistulas can be primary (associated with complicated abdominal aortic aneurysm) or secondary (associated with graft repair). Epidemiology The annual incidence of primary aortoenteric fistulas is thou...
Article

Aphthoid ulceration

Aphthoid ulcers are shallow ulcers of the gastrointestinal mucosa. Pathology Aetiology infective inflammatory conditions Yersinia enterocolitis amoebic enterocolitis cytomegalovirus enterocolitis noninfective inflammatory conditions Crohn disease idiopathic granulomatous gastritis vasc...
Article

Appendiceal carcinoid

Appendiceal carcinoids are rare overall but represent the most common tumour of the appendix. The appendix is also one of the most common (but not the most common) locations for gastrointestinal carcinoid tumours.  Clinical presentation Appendiceal carcinoids can present as the obstructive cau...
Article

Appendiceal intussusception

Appendiceal intussusception happens when appendix segment is pulled into itself or into the cecum. This condition can mimic various chronic and acute abdominal conditions. It is an important entity to recognise since it could be mistaken for a caecal mass. Epidemiology Appendiceal intussuscept...
Article

Appendiceal mucocele

Appendiceal mucoceles occur when there is an abnormal accumulation of mucin causing abnormal distention of the appendix. They are due to either nonneoplastic process, such as luminal obstruction, or mucin-secreting epithelial tumours. Epidemiology The reported prevalence at appendectomy is 0.2...
Article

Appendicitis (summary)

Appendicitis occurs when there is inflammation of the vermiform appendix. It is a very common condition and is a major cause of abdominal surgery in young patients. CT is the most sensitive modality to detect appendicitis although its use should be limited because of the radiation dose required ...
Article

Appendicolith

An appendicolith is a calcified deposit within the appendix. They are present in a large number of children with acute appendicitis and may be an incidental finding on an abdominal radiograph or CT. Incidence may be increased among patients with a retrocaecal appendix. Overall they are seen in 1...
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Appendicular abscess

Appendicular abscess is considered the most common complication of acute appendicitis. Radiographic features Ultrasound Ultrasound is the first investigation advised to evaluate a suspected appendicular pathology. Findings of an appendicular abscess include: fluid collection (hypoechoic) in ...
Article

Appendicular artery

The appendicular artery is a branch of the ileal or posterior caecal branch of the ileocolic artery, which is from the superior mesenteric artery. It courses posteriorly to the terminal ileum in the free wall of the mesoappendix to supply the appendix.
Article

Appendix

The appendix or vermiform appendix is a blind muscular tube that arises from the caecum, which is the first part of the large bowel. Gross anatomy The appendix arises from the posteromedial surface of the caecum, approximately 2-3 cm inferiorly to the ileocaecal valve, where the taena coli con...
Article

Appleby procedure

The Appleby procedure is a type of pancreatic cancer resection.  For some patients with pancreatic cancer involving the body and tail of the pancreas, involvement of the coeliac axis is a classic contraindication to pancreaticoduodenectomy (Whipple procedure).  With the Appleby procedure, ther...
Article

Apple core sign (colon)

The apple core sign, also known as a napkin ring sign (bowel), is most frequently associated with constriction of the lumen of the colon by a stenosing annular colorectal carcinoma. Differential diagnosis The appearance of the apple-core lesion of the colon also can be caused by other diseases...
Article

Apple-peel intestinal atresia

Apple-peel intestinal atresia, also known as type IIIb or Christmas tree intestinal atresia, is a rare form of small bowel atresia in which the duodenum or proximal jejunum ends in a blind pouch and the distal small bowel wraps around its vascular supply in a spiral resembling an apple peel. Oft...
Article

Arc of Buhler

The arc of Buhler (AOB) is a persistent embryonic anastomotic branch between the 10th and 13th ventral segmental arteries, resulting in a connection between the coeliac artery and superior mesenteric artery (SMA). This arch is independent of both the gastroduodenal and dorsal pancreatic artery. ...
Article

Arc of Riolan

The arc of Riolan (AOR), also known as the mesenteric meandering artery (of Moskowitz) or central anastomotic mesenteric artery, is an arterio-arterial anastomosis between the superior and inferior mesenteric arteries. Gross anatomy It is an inconstant artery that connects the proximal superio...

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