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.
1,293 results found
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 (D2 & D4), pancreas and retroperitoneal segments of the ascending an...
Article
Anterior resection syndrome
Anterior resection syndrome refers to wide spectrum of symptoms which develop post-sphincter preserving rectal resection for rectal cancer.
Pelvic radiotherapy is a known risk factor to develop anterior resection syndrome.
Epidemiology
There have been reports that up to 47% of patients who un...
Article
Anterior right subhepatic space
The anterior right subhepatic space is a potential space between the inferior surface of the right lobe of the liver and the transverse colon.
Gross Anatomy
The anterior right subhepatic space is separated from Morison’s pouch (also known as the posterior right subhepatic space) by the transve...
Article
Anthrax
Anthrax is a zoonosis caused by Bacillus Anthracis. There are four types of anthrax: inhalational anthrax (also known as woolsorter's disease and ragsorter's disease), cutaneous anthrax, injection anthrax and intestinal anthrax.
Epidemiology
The disease burden of anthrax decreased so dramatica...
Article
Antibiotic-associated diarrhea
Antibiotic-associated diarrhea can be broadly divided into two groups:
Clostridioides difficile colitis
non-specific diarrhea
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 b...
Article
Antineutrophil cytoplasmic antibody
Antineutrophil cytoplasmic antibodies (ANCAs) are a heterogenous class of IgG autoantibodies raised against the cellular contents of neutrophils, monocytes and endothelial cells 1. Under indirect immunofluorescence (IIF) microscopy, three ANCA staining patterns are observed, based on the varying...
Article
Antiphospholipid syndrome
Antiphospholipid syndrome is a systemic autoimmune disorder. It is usually defined as the clinical complex of vascular occlusion and ischemic events occurring in patients who have circulating antiphospholipid antibodies.
Clinical presentation
Antiphospholipid syndrome is characterized by venou...
Article
Antral nipple sign (pyloric stenosis)
The antral nipple sign refers to redundant pyloric mucosa protruding into the gastric antrum and is seen in hypertrophic pyloric stenosis on ultrasound examination.
See also
cervix sign (pyloric stenosis)
target sign (pyloric stenosis)
Article
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 of 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 midli...
Article
Aortoenteric fistula
Aortoenteric fistulas are pathologic communications between the aorta (or aortoiliac tree) and the gastrointestinal tract and represent an uncommon cause of catastrophic gastrointestinal hemorrhage.
Aortic fistulas may be considered primary (associated with a complicated abdominal aortic aneury...
Article
Aphthoid ulceration
Aphthoid ulcers are shallow ulcers of the gastrointestinal mucosa.
Pathology
Etiology
infective inflammatory conditions
Yersinia enterocolitis
amoebic enterocolitis
cytomegalovirus enterocolitis
noninfective inflammatory conditions
Crohn disease
idiopathic granulomatous gastritis
vascu...
Article
Appendiceal carcinoid
Appendiceal carcinoids are rare overall but represent the most common tumor of the appendix. The appendix is also one of the most common (but not the most common) locations for gastrointestinal carcinoid tumors.
Clinical presentation
Appendiceal carcinoids can present as the obstructive cause...
Article
Appendiceal diverticulitis
Appendiceal diverticulitis (plural diverticulitides) is a rare condition in which there is acute inflammation of a diverticulum arising from the vermiform appendix.
Epidemiology
Historically appendiceal diverticulitis has been thought to be a rare diagnosis. However a study from 2015 which ret...
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 recognize since it could be mistaken for a cecal mass.
Epidemiology
Appendiceal intussuscepti...
Article
Appendiceal mucocele
Appendiceal mucoceles occur when there is an abnormal accumulation of mucin causing abnormal distention of the vermiform appendix due to various neoplastic or non-neoplastic causes.
Epidemiology
The reported prevalence at appendectomy is 0.2-0.3%. They are thought to typically present in middl...
Article
Appendicitis
Appendicitis is inflammation of the vermiform appendix. It is a very common condition in general radiology practice and is one of the main reasons for abdominal surgery in young patients. CT is the most sensitive modality to detect appendicitis.
Epidemiology
Acute appendicitis is typically a d...
Article
Appendicitis (summary)
This is a basic article for medical students and other non-radiologists
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 a...
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 retrocecal appendix. Overall they are seen in 10...
Article
Appendicular abscess
Appendicular abscess is considered the most common complication of acute appendicitis, in particular after a perforated appendix.
Radiographic features
Appendicular abscesses can arise either in the peritoneal cavity or the retroperitoneal space.
Ultrasound
Ultrasound is the first investiga...
Article
Appendicular artery
The appendicular artery is a branch of the ileal or posterior cecal 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 (plural: appendices) is a blind muscular tube that arises from the cecum, which is the first part of the large bowel.
Gross anatomy
The appendix arises from the posteromedial surface of the cecum, approximately 2-3 cm inferior to the ileocecal valve, where th...
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 celiac axis is a classic contraindication to pancreaticoduodenectomy (Whipple procedure).
With the Appleby procedure, there...
Article
Apple core sign (colon)
The apple core sign, also known as the 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 diseas...
Article
Apple core sign (disambiguation)
The apple core sign has been described in two different pathologies:
apple core sign (colon)
apple core sign (femur)
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 celiac 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, also known as the mesenteric meandering artery (of Moskowitz) or central anastomotic mesenteric artery, is an arterioarterial anastomosis between the superior and inferior mesenteric arteries.
Gross anatomy
It is an inconstant artery that connects the proximal superior mesen...
Article
Areae gastricae
Areae gastricae are a normal finding on double contrast images of the stomach.
Radiographic features
fine reticular network of barium-coated grooves between 1-5 mm islands/areas of gastric mucosa
may be seen in ~70-80% of patients if there is adequate high-density barium coating of the stomac...
Article
A ring (esophagus)
A rings are a type of distal esophageal ring. They are above the B ring and occur a few centimeters proximal to the gastro-esophageal junction. They represent a physiological contraction of esophageal smooth muscle covered by mucosa. A rings are uncommonly symptomatic.
Article
Arrowhead sign (cecum)
The arrowhead sign refers to the focal cecal thickening centered on the appendiceal orifice, seen as a secondary sign in acute appendicitis. The contrast material in the cecal lumen assumes an arrowhead configuration, pointing at the appendix.
The arrowhead sign is applicable only when enteri...
Article
Arterial occlusive mesenteric ischemia
Arterial occlusive mesenteric ischemia can be a life-threatening event related to obstruction of the mesenteric arteries, most commonly the superior mesenteric artery (SMA), supplying the small bowel and colon. It is the most common cause of mesenteric ischemia.
Epidemiology
An acute occlusi...
Article
Asbestos-related diseases
Asbestos-related disease, in particular affecting the lung, comprise of a broad spectrum of entities related to the inhalational exposure to asbestos fibers. They can be divided into benign and malignant processes 1-3.
Benign pleural and parenchymal lung disease
asbestos-related benign pleural...
Article
Ascariasis
Ascariasis is due to infection with the Ascaris lumbricoides adult worm and typically presents with gastrointestinal or pulmonary symptoms, depending on the stage of development.
Epidemiology
Ascaris lumbricoides is widely distributed in tropical and subtropical regions and in other humid ar...
Article
Ascaris-induced pancreatitis
Ascaris-induced pancreatitis is the most common form of parasite-induced pancreatitis.
Epidemiology
Ascariasis in parts of India is the second most common form of pancreatitis after gallstones 1. It is rare outside of endemic regions however.
Clinical presentation
The presentation will be si...
Article
Ascending colon
The ascending colon is the second part of the large bowel.
Gross anatomy
The ascending colon is the continuation of the cecum superior to the ileocecal valve. It is secondarily retroperitoneal, although it has its own mesentery in approximately 25% of patients and is 15 cm in length 1,2.
The ...
Article
Ascites
Ascites (hydroperitoneum is a rare synonym) is defined as an abnormal amount of intraperitoneal fluid.
Terminology
Ascites (plural is same word) tends to be reserved for relatively sizable amounts of peritoneal fluid. The amount has not been defined formally, however it is noted that physiolog...
Article
Ascitic fluid cholesterol level
Ascitic fluid cholesterol level estimation is a simple and precise test for differentiating malignant ascites from non-malignant (cirrhotic) ascites 5-9.
Pathology
Ascites is the abnormal collection of fluid within the peritoneal cavity. Malignant ascites comprises ~10% and is usually seconda...
Article
Aspiration
Aspiration occurs if liquid or solid material enters the subglottic lower respiratory tract.
Terminology
The term aspiration is used if material passes below the level of the vocal folds, i.e. subglottic. If material enters the larynx but remains above the vocal folds this is called penetratio...
Article
Aspiration bronchiolitis
Aspiration bronchiolitis, or diffuse aspiration bronchiolitis, is a condition characterized by a chronic inflammation of bronchioles caused by recurrent aspiration of foreign particles.
Epidemiology
Associations
neurologic disorders: ~ 50% 3
dementia: ~50% 3
Risk factors
Patients with esop...
Article
Asplenia
Asplenia refers to absence of the spleen thereby leading to deficient splenic function.
Epidemiology
Seen in 3% of neonates with structural heart disease and in 30% of patients who die from cardiac malposition. The male-to-female ratio is 2:1.
Pathology
Asplenia can be classified into two t...
Article
Atresia
Atresia (plural: atresias) refers to a situation where there is absence, underdevelopment or abnormal closure, of a normal anatomical tubular structure or opening.
Contrast this with agenesis which refers to the complete absence of any anatomical structure including its primordial precursors.
...
Article
Atrial-esophageal fistula
Atrio-esophageal fistulas are rare pathological connections between the left atrium and the esophagus.
Clinical presentation
The presentation is non-specific. Patients may complain of fever, malaise, and/or dysphagia, or present with neurological symptoms 3.
Pathology
The chief cause of at...
Article
Atrophic gastritis
Atrophic gastritis is a chronic condition of autoimmune and non-autoimmune etiology.
Pathology
Two types of atrophic gastritis have been described 1-3:
type A: autoimmune
gastric body and fundus atrophy secondary to antiparietal cell antibodies
decreased secretion of acid and intrinsic fac...
Article
Autoimmune pancreatitis
Autoimmune pancreatitis (AIP) is a form of chronic pancreatitis associated with autoimmune manifestations on clinical, histological, and laboratory grounds 1.
Distinguishing this entity from other forms of chronic pancreatitis (such as alcohol-induced) is important as steroid treatment is effec...
Article
Autosplenectomy
Autosplenectomy denotes spontaneous infarction of the spleen with resulting hyposplenism.
Epidemiology
Autosplenectomy is most frequently encountered in patients with homozygous sickle cell disease, although it has also been reported in pneumococcal septicemia 1, and systemic lupus erythematos...
Article
Backwash ileitis
Backwash ileitis is seen in patients with ulcerative colitis (UC), where the entire colon is involved. In such cases the terminal ileum is edematous.
Backwash ileitis extends contiguously backward from the cecum without skip regions. One source estimates it to occur in 6% of patients with UC, a...
Article
Ball of wool sign (hydatid cyst)
The ball of wool sign, also referred to as the yarn sign or congealed water lily sign, is an ultrasound appearance, representing degeneration of hydatid cysts (WHO class CE 4). The inner side of the cyst detaches from the cyst wall and folds on itself, causing a change from anechoic (fluid) to a...
Article
Balloon-occluded retrograde transvenous obliteration
Balloon-occluded retrograde transvenous obliteration (BRTO) is a technique used by interventional radiologists in the treatment of gastric varices, particularly those with prominent infra-diaphragmatic portosystemic venous shunts (e.g. gastro-renal and gastro-caval shunts).
The technique is mor...
Article
Balthazar score
The Balthazar score is a subscore within the CT severity index (CTSI) for grading of acute pancreatitis.
The CTSI sums two scores:
Balthazar score: grading of pancreatitis (A-E)
grading the extent of pancreatic necrosis
The Balthazar score was originally used alone, but the addition of a sc...
Article
Bannayan–Riley–Ruvalcaba syndrome
Bannayan–Riley–Ruvalcaba syndrome (BRRS or BRR syndrome) is a very rare autosomal dominant hamartomatous disorder caused by a mutation in the PTEN gene. It is considered in the family of hamartomatous polyposis syndrome.
There are no formal diagnostic criteria for this disease, but characterist...
Article
Bariatric embolization
Bariatric embolization is an interventional procedure performed with a view to inducing weight-loss in the treatment of obesity. Evidence from clinical trials suggests that the procedure is well tolerated and has a good safety profile. Early studies demonstrate a mild-moderate beneficial effect....
Article
Bariatric intragastric balloon therapy
Bariatric intragastric balloon therapy is a known therapy for weight loss, which involves a balloon being endoscopically-placed or swallowed and inflated inside the lumen of the stomach. The balloon resides in the stomach and the mechanism of action is presumably due to stretching the stomach, i...
Article
Barium intravasation
Barium intravasation represents the feared - and fortunately very rare - complication of passage of barium sulfate contrast medium from the GI tract into the bloodstream.
Epidemiology
Entry of barium into the bloodstream, usually the venous circulation is very rare, and a paper published in 20...
Article
Barium peritonitis
Barium peritonitis is a rare complication of gastrointestinal barium studies, and occurs when there is gastrointestinal tract perforation and spillage of barium contrast agent into the peritoneal cavity resulting in peritonitis, granuloma and stone formation 1.
Pathology
Barium sulfate in the ...
Article
Barium studies of the small bowel
Barium studies of the small intestine are still considered an effective modality to show the bowel loops in a cost-effective way.
Procedure
Small bowel follow through (SBFT) or transit study
routine investigation for delineation of all parts the small bowel
done with barium meal after havin...
Article
Barium sulfate contrast medium
Barium sulfate (BaSO4), often just called barium in radiology parlance, is an ionic salt of barium (Ba), a metallic chemical element with atomic number 56. Barium sulfate forms the basis for a range of contrast media used in fluoroscopic examinations of the gastrointestinal tract. Unlike barium ...
Article
Barium swallow
Barium swallow is a dedicated test of the pharynx, esophagus, and proximal stomach, and may be performed as a single or double contrast study. The study is often "modified" to suit the history and symptoms of the individual patient, but it is often useful to evaluate the entire pathway from the ...
Article
Barolith
A barolith consists of inspissated barium sulfate associated with feces seen rarely, after barium studies for imaging the gastrointestinal tract. Since barium sulfate is insoluble, it can in rare cases precipitate in the bowel, sometimes becoming symptomatic with a significant delay (from few we...
Article
Barrett esophagus
Barrett esophagus is a term for intestinal metaplasia of the esophagus. It is considered the precursor lesion for esophageal adenocarcinoma.
Epidemiology
Barrett esophagus is thought to have a prevalence of 3-15% in patients with reflux esophagitis. Mean age at diagnosis is 55 years old 5. Ris...
Article
Beak sign (pyloric stenosis)
Beak sign in pyloric stenosis is one of the fluoroscopic (barium meal) findings which is useful in the diagnosis of congenital hypertrophic pyloric stenosis.
Radiographic features
Barium meal
A beak-like tapering projection of barium is seen entering into the narrowed and compressed pyloric c...
Article
Behçet disease
Behçet disease is a multisystemic and chronic inflammatory vasculitis of unknown etiology.
Epidemiology
The mean age at which Behçet disease occurs is 20-30 years. The disease is most prevalent in the Mediterranean region, Middle East and East Asia. The highest incidence has been reported in T...
Article
Benign esophageal lesions
Benign esophageal lesions are less symptomatic than malignant esophageal lesions, making up for only 1% of clinically apparent esophageal lesions.
Pathology
esophageal leiomyoma (>50%)
may calcify
esophageal fibrovascular polyp (~12.5%)
may contain fat
esophageal duplication cyst (10%)
oe...
Article
Benign post-traumatic pseudopneumoperitoneum
Benign post-traumatic pseudopneumoperitoneum is the presence of ectopic gas typically between the 5th-10th intercostal spaces after high-energy trauma in the absence of other causes of pseudopneumoperitoneum such as pneumomediastinum 9.
Epidemiology
Occurs with an incidence of 5% post-trauma...
Article
Bethesda criteria of hereditary non-polyposis colorectal cancer
The Bethesda criteria are an alternative to the Amsterdam criteria for the clinical diagnosis of hereditary non-polyposis colorectal cancer (HNPCC).
Diagnosis of HNPCC is made if any of the following criteria are fulfilled:
Amsterdam criteria are met
2 or more HNPCC related malignancies
pa...
Article
Bezoar
Bezoars are accumulations of indigestible contents within the gastrointestinal tract 2.
Pathology
There are several types depending on the predominant components:
trichobezoar: a bezoar formed from hair, this has also been called Rapunzel syndrome when the tail of the trichobezoar extends so...
Article
Bilateral adrenal gland hyperenhancement
Bilateral adrenal gland hyperenhancement or intense adrenal enhancement may be a feature of hypotension and forms part of the CT hypoperfusion complex.
Adrenal gland hyperenhancement has been described in pediatric and small adult series or individual cases of hemorrhagic shock, pancreatitis, s...
Article
Biliary cast syndrome
Biliary cast syndrome is a complication that occurs after liver transplantation, where dark solid bilirubin casts develop in the biliary tree, causing biliary obstruction.
Terminology
This should be differentiated from biliary sludge, which represents thickened bile that has not precipitated.
...
Article
Biliopancreatic diversion
Biliopancreatic diversion was a development on the jejunoileal bypass type of bariatric surgery. It can be performed with or without a duodenal switch.
The procedure involves
distal gastrectomy, with the formation of a gastric pouch
gastroenterostomy, with the formation of a ~250 cm Roux limb...
Article
Billroth II gastrojejunostomy
Billroth II gastrojejunostomy is a procedure that has been performed for tumor or severe ulcer disease in the distal stomach.
There are many variations on the procedure, but they generally involve resection of the diseased portion of the distal stomach and a side-to-side anastomosis of the resi...
Article
Billroth I reconstruction
Billroth I is a type of surgical reconstruction that has been performed after partial gastrectomy, usually in the setting of tumor or ulcer resection.
The key feature of a Billroth I reconstruction is the formation of an end-to-end anastomosis between the proximal remnant stomach and duodenal s...
Article
Bird beak sign (esophagus)
The bird's beak sign of the esophagus is used to refer to the tapering of the inferior esophagus in achalasia. The same appearance (although it is difficult to see the similarity) is also referred to as the rat-tail sign.
The appearance, although classically occurring in primary achalasia, can ...
Article
Bird beak sign (right colon)
The bird beak sign of the right colon is tapering obstruction of the inferior part of right colon seen on contrast enema or CT scan with rectal contrast indicating cecal volvulus.
This sign can help to differentiate cecal volvulus from cecal bascule, in particular on a contrast/barium enema stu...
Article
Bird beak sign (sigmoid colon)
Bird's beak sign of the sigmoid is one of the signs of sigmoid volvulus. It represents gradual narrowing/tapering of the sigmoid colon up to the level of obstruction during contrast/barium insertion to the rectum or on CT.
When located in the sigmoid colon, it suggests the diagnosis of sigmoid ...
Article
Blind loop syndrome
Blind loop syndrome (or "blind pouch syndrome") is an event that may occur after an end-to-end or end-to-side bowel anastomosis. Dilatation and stasis of the bypassed bowel may lead to bacterial overgrowth, breakdown of bile salts, and result in nutritional problems. It may even eventually lead ...
Article
Bochdalek hernia features (mnemonic)
A helpful mnemonic for remembering the features of a Bochdalek hernia is:
5 Bs
Mnemonic
B: Bochdalek
B: big
B: back and lateral, usually on the left side
B: baby
B: bad (associated with pulmonary hypoplasia)
To remember the side in which a Bochdalek hernia more commonly occurs (and to co...
Article
Body imaging
Body imaging is the term assigned to cross-sectional imaging of the body, which radiologically refers to the chest, abdomen and pelvis. It is often used by radiologists who report this region (sometimes known as body imagers/radiologists) to differentiate their primary area of interest from othe...
Article
Body packing
Body packing refers to the internal concealment of drugs within the gastrointestinal tract or other orifices. People who do this may be called body packers, (drug) mules, stuffers, couriers or swallowers. Drugs may be concealed within condoms, foil, latex or cellophane.
Epidemiology
There is ...
Article
Boerhaave syndrome
Boerhaave syndrome refers to an esophageal rupture secondary to forceful vomiting and retching.
Epidemiology
It tends to be more prevalent in males, with alcoholism a risk factor. The estimated incidence is ~ 1:6000.
Clinical presentation
They are often associated with the clinical triad (Ma...
Article
Borchardt's triad (gastric volvulus)
Borchardt's triad comprises of the classic three symptoms diagnostic of gastric volvulus 1:
severe sudden epigastric pain
intractable retching without vomiting
inability to pass a nasogastric tube
Article
Bouveret syndrome
Bouveret syndrome refers to a gastric outlet obstruction secondary to impaction of a gallstone in the pylorus or proximal duodenum. Thus, it can be considered a very proximal form of gallstone ileus.
Clinical presentation
Bouveret syndrome occurs most commonly in elderly women. The presenting...
Article
Bowel and mesenteric trauma
Bowel and mesenteric trauma can result from blunt force, penetrating and iatrogenic trauma.
Epidemiology
The bowel and mesentery are injured in ~2.5% (range 0.3-5%) of blunt force abdominal trauma 1,3,5,8. However not surprisingly, bowel and mesenteric injuries are more frequent after penetrat...
Article
Bowel dilatation (summary)
This is a basic article for medical students and other non-radiologists
Bowel dilatation is a relatively non-specific sign than can be seen on most imaging modalities. In bowel obstruction, dilatation may be demonstrated on a plain radiograph providing the bowel is filled with gas.
Reference a...
Article
Bowel obstruction
Bowel obstructions are common and account for 20% of admissions with "surgical abdomens". Radiology is important in confirming the diagnosis and identifying the underlying cause.
Bowel obstructions are usually divided according to where the obstruction occurs, and since imaging appearances, und...
Article
Bowel perforation
Bowel perforation, either small bowel perforation or large bowel perforation, can occur in many different settings, but the more common are
bowel obstruction (both small and large)
bowel ischemia
severe ulcer disease
diverticular disease
infection
malignant diseases
gastrointestinal tumor...
Article
Bowel perforation (summary)
This is a basic article for medical students and other non-radiologists
Bowel perforation is an acute surgical emergency where there is a release of gastric or intestinal contents into the peritoneal space.
Reference article
This is a summary article; read more in our article on bowel perfora...
Article
Bowel sacculation (mnemonic)
A mnemonic to remember causes of bowel sacculation is:
MISC
Mnemonic
M: metastasis
I: ischemia
S: scleroderma
C: Crohn disease
Article
Bowel wall thickening
Bowel wall thickening is a useful finding on imaging studies and has a number of different causes.
Pathology
The reason for bowel wall thickening depends on the underlying etiology but includes submucosal edema, hemorrhage, and neoplastic infiltration.
Radiographic features
In describing bow...
Article
B ring
The B ring is a mucosal ring that develops in the distal esophagus at the gastroesophageal junction (Z line).
Terminology
If the ring becomes symptomatic, then it is usually termed a Schatzki ring, although some use the terms synonymously.
Pathology
Its development is thought to be a reacti...
Article
Broad ligament hernia
Broad ligament hernias (alternative plural: herniae) are a type of internal hernia in which small bowel passes through a congenital or acquired defect in the broad ligament.
Epidemiology
Broad ligament herniation is very rare and accounts for 4%-7% of all internal hernias 1.
Clinical presenta...
Article
Bronchogenic cyst vs esophageal duplication cyst
Bronchogenic cysts and esophageal duplication cysts are embryological foregut duplication cysts and are also differential diagnoses for a cystic mediastinal mass.
Differences
Symptoms
asymptomatic bronchogenic cyst
symptomatic esophageal cyst in the case of peptic ulceration
Plain radiograp...
Article
Brunner gland adenoma
Brunner gland adenomas are hyperplastic areas of the Brunner glands within the duodenum that are greater than 1 cm. They tend to be 1-2 cm in diameter, although case reports have described tumors of up to 12 cm diameter. Where the diameter of focal hyperplasia is less than 1 cm, the term Brunner...
Article
Brunner gland hyperplasia
Brunner gland hyperplasia results from disproportionate overgrowth of Brunner glands in the duodenum as a result of hyperacidity.
Hyperplasia begins at the pylorus and extends distally within the first 2/3rds of the duodenum. Where the focal growth of hyperplastic cells is greater than 1 cm in ...