Computed tomographic (CT) enterography is a non-invasive technique for diagnosis of small bowel disorders.
evaluates the entire thickness of the bowel wall
offers information about the surrounding mesentery, the mesenteric vasculature and the perienteric fat
detect occult gastroi...
CT hypoperfusion complex refers to the predominantly abdominal imaging features that occur in the context of profound hypotension. Multiple abdominal organs can display atypical appearances not related to the initial trauma but reflect alterations in perfusion secondary to hypovolemia which affe...
CT peritoneography is an examination used to assess difficulties with peritoneal dialysis.
Recurrent peritonitis with difficulty with fluid exchange, abdominal wall or genital soft tissue edema, localized bulging of the abdomen, and poor ultrafiltration.
CT polytrauma/multitrauma, also called trauma CT, whole body CT (WBCT) or panscan, is an increasingly used investigation in patients with multiple injuries sustained after significant trauma.
Clinical assessment and mechanism of injury may underestimate injury severity by 30% 8. There is some e...
The CT severity index (CTSI) is based on findings from a CT scan with intravenous contrast to assess the severity of acute pancreatitis. The severity of computed tomography findings have been found to correlate well with clinical indices of severity.
The CTSI sums two scores:
The cupola sign is seen on a supine chest/abdominal radiograph in the presence of pneumoperitoneum.
It refers to non-dependent gas that rises within the abdominal cavity of the supine patient to accumulate underneath the central tendon of the diaphragm in the midline. It is seen as lucency ove...
The cystic duct connects the neck of the gallbladder to the common hepatic duct (CHD), draining bile to and from the biliary tree.
The confluence of the cystic duct and the common hepatic duct forms the common bile duct (CBD). The cystic duct is approximately 2-3 cm long and 2-3 ...
Cystic fibrosis (CF) is an autosomal recessive genetic disease that affects the exocrine function of the lungs, liver, pancreas, and small bowel resulting in progressive disability and multisystem failure. This article is a general discussion of the disease. Each organ system will be discussed s...
Abdominal manifestations in cystic fibrosis (CF) are common, varied and nearly all organ systems can be affected, and it should be remembered that only 39% of patients with cystic fibrosis have pulmonary symptoms as their sole complaint 1. Not only that, but 7% of cystic fibrosis patients do not...
The differential for cystic lesions of the pancreas includes:
intraductal papillary mucinous neoplasm (IPMN)
serous cystadenoma uncommonly uni/macrolocular
simple pancreatic cyst
pancreatic cysts occur in association with
von Hippel Lindau syndrome
A mnemonic for causes of cystic lesions in the spleen is:
Cystic or necrotic appearing lymph nodes can be caused by a number of infectious, inflammatory or malignant conditions:
squamous cell carcinoma metastases
plasmacytoid T-cell leukemia
acute myeloid leukemia
herpes simplex lymphadenit...
Cystic retroperitoneal lesions can carry a relatively broad differential, which includes:
retroperitoneal mucinous cystadenoma
retroperitoneal cystic teratoma
retroperitoenal cystic mesothelioma
pseudomyxoma retroperitonei with cystic change
perianal mucinous c...
De Garengeot hernias are femoral hernias that contain the appendix.
It is not to be confused with Amyand hernia, which is an appendix-containing inguinal hernia.
It is a rare phenomenon, with only 1% of all femoral hernias containing the appendix (and usually found incidentally a...
Degloving bowel injuries are a rare type of bowel and mesenteric injury only being described a handful of times in the literature 1-5. In these injuries the bowel is stripped of its mesentery and muscle, leaving a "mucosal tube" 2,3. Perforation may or may not be present.
Degloving injuries can refer to a number of conditions:
degloving soft tissue injury
Morel-Lavallée lesion (closed degloving soft tissue injury)
intramuscular degloving injury
degloving bowel injury
Dehiscence is a general term referring to 'splitting open' and is used in a variety of contexts in medicine generally and radiology more specifically.
The two most common usages are:
splitting open of a wound (e.g. sternal dehiscence)
loss of bone separating one structure from another (e.g. ...
Dental caries are cavities in teeth ('caries' is both the singular and plural form). They are very common and can lead to serious morbidity.
Tooth decay is asymptomatic in its early stages. Once the enamel has been breached and the dentin is exposed then people may exper...
The dependent viscera sign is one of the signs of diaphragmatic rupture on axial CT or MR images, where herniated viscera lie against the posterior thoracic wall in a dependent position, as they are no longer supported by the diaphragm.
collar sign (or hourglass sign)
The descending colon is the continuation of the transverse colon after the left colic flexure, where the colon loses its mesentery.
The descending colon measures up to 25 cm in length and is secondarily retroperitoneal. It descends down attached to the left posterior abdominal w...
Desmoplastic small round cell tumors are a rare and highly aggressive primary peritoneal malignancy.
They are usually seen in young adolescents and has male predominance with a mean survival of 2-3 years.
It usually presents with a palpable abdominal mass a...
Diabetes mellitus (DM) often referred to simply as diabetes, is a group of metabolic conditions characterized by hyperglycemia.
These conditions should not be confused with diabetes insipidus which is clinically distinct and not related to hyperglycemia.
If a patient with diabete...
The diaphragm is the dome-shaped muscle that separates the thoracic cavity from the abdominal cavity, enclosing the inferior thoracic aperture.
The muscular fibers of the diaphragm originate around the circumference of the inferior thorax and converge to a common insertion point ...
Diaphragmatic rupture often results from blunt abdominal trauma. The mechanism of injury is typically a motor-vehicle collision.
Given that the most common mechanism is motor vehicle collisions, it is perhaps unsurprising that young men are most frequently affected. The estimated ...
Dieulafoy lesions are uncommon but important causes of acute upper gastrointestinal bleeding. A Dieulafoy lesion is characterized by a dilated tortuous submucosal artery that erodes overlying gastrointestinal mucosa most commonly found in the stomach.
contributes to ~1.5% of all...
Diffuse colonic nodularity on barium enema or CT colonography has a range of possible etiologies:
lymphoid hyperplasia (tend to be small and discrete)
lymphoma (tend to be larger nodules and confluent)
urticaria (closely spaced polygonal lesions, history is often helpful)
Diffuse/distal esophageal spasm (DOS) is a motility disorder of the esophagus. On barium swallow, diffuse esophageal spasm may appear as a corkscrew or rosary bead esophagus, but this is uncommon. Manometry is the gold-standard diagnostic test.
Diffuse esophageal spasm differs from hypercontrac...
Diffuse or disseminated peritoneal leiomyomatosis, also known as leiomyomatosis peritonealis disseminata, is an exceedingly rare benign disorder characterized by multiple vascular leiomyomas growing along the submesothelial tissues of the abdominopelvic peritoneum.
It is usually d...
Diffuse small bowel disease may be caused by a number of conditions may be generalized multisystem disorders or conditions that effect the bowel in a global fashion:
Discrete colonic ulcerations are nonspecific findings, and can be due to:
Distal intestinal obstruction syndrome (DIOS) is one the of many abdominal manifestations of cystic fibrosis. In older children or young adults with cystic fibrosis, the distal small bowel may become obstructed with a mucofaeculent material in the distal ileum and right colon.
Diverticular disease generally refers to phenomenon involving acquired diverticula along the lower gastrointestinal tract. It covers a range of pathologies and may account for a variety of presentations. Diverticulosis is largely asymptomatic however 4% of individuals with diverticula develop di...
This is a basic article for medical students and other non-radiologists
Diverticulitis is one of the presentations of diverticular disease and is most often a complication of colonic diverticulosis. Differentiating one from the other is critical since uncomplicated diverticulosis is mostly asym...
Diverticula are outpouchings of a hollow viscus and can be either true or false.
Occasionally a diverticulum is used in a more general sense to mean the outpouching of other anatomical structures, e.g. frontal intersinus septal cells are hypothesized to form as diverticula from the frontal sinu...
The dog ear sign represents the presence of fluid or blood in the pelvic peritoneal recess on a supine abdominal radiograph. The appearance of the sign comes from a convex soft-tissue density representing fluid or blood in the lateral pelvic peritoneal recess separated from the bladder by a thin...
The doge cap sign, also referred to as Morison pouch sign, is a radiographic sign of pneumoperitoneum. It presents as a triangular-shaped gas lucency or can be crescent shaped, or semicircular is usually bound by the 11th rib in the right upper quadrant on abdominal radiographs due to air in the...
Agenesis of the dorsal pancreas is an extremely rare congenital pancreatic anomaly.
While complete agenesis of the dorsal pancreas is extremely rare, partial agenesis of the dorsal pancreas is thought to be more common than ventral pancreatic agenesis 4.
While many pati...
Double barrel sign is an imaging appearance of two lumens adjacent to each other.
It can be seen in:
dilated bile duct adjacent to portal vein
double barrel aorta: aortic dissection
double barrel esophagus: esophageal dissection
The double bubble sign is seen in infants and represents dilatation of the proximal duodenum and stomach. It is seen in both radiographs and ultrasound, and can be identified antenatally 2.
Causes include 1,2:
The double contrast barium enema is rapidly being replaced by CT colonography, but remains in some centers for:
the detection of polyps and colorectal cancer
follow up screening for postoperative colorectal cancer
evaluation of diverticular disease
investigation of non-sp...
Double contrast barium enema (DCBE) technique is a method of imaging the colon with fluoroscopy. "Double contrast" refers to imaging with the positive contrast of barium sulfate contrast medium (rarely water-soluble iodinated contrast) as well as with the negative contrast of gas (CO2 preferable...
The double duct sign refers to the presence of simultaneous dilatation of the common bile and pancreatic ducts. Being an anatomical sign it can be seen on all modalities that can visualize the region, including: MRI, CT, ultrasound and endoscopic retrograde cholangiopancreatography (ERCP).
The double track sign is a radiological sign described in pyloric stenosis on various imaging modalities.
Double streaks of barium passing through the narrow pylorus 1.
On fluid aided real-time examination, the pyloric fluid is compressed into smaller tracks as it is...
The doughnut sign can refer to a variety of different signs:
doughnut sign (bone scan)
doughnut sign (bowel)
crescent in a doughnut sign (bowel)
doughnut sign (orbit)
Downhill esophageal varices are an uncommon type of esophageal varices associated with superior vena cava (SVC) obstruction.
Downhill oesophagal varices are less frequently seen. It is seen in less than 0.5% of routine upper endoscopies. Most common etiology is superior vena obstr...
Down syndrome (or trisomy 21) is the most common trisomy and also the commonest chromosomal disorder. It is a major cause of intellectual disability, and also has numerous multisystem manifestations.
According to the World Health Organization (WHO), the approximate worldwide incid...
Retained appendicoliths, also called dropped or slipped appendicoliths, are appendicoliths that have been inadvertently left inside the peritoneal cavity following appendectomy.
Patients may be asymptomatic in some cases. Other cases may present with infective symptoms du...
The duct penetrating sign is a radiographic sign which can be useful in differentiating between focal pancreatitis (inflammatory pancreatic mass) from pancreatic carcinoma.
A positive sign is when a mass is penetrated by an unobstructed pancreatic duct; this makes focal pancreatitis the most li...
The Dukes staging system is a classification system for colorectal cancer. This system is now mainly of historical interest as it has largely been replaced by the TNM staging system. It is not recommended for clinical practice.
Dukes A: invasion into but not through the bowel wall (90% 5 year s...
Duodenal adenocarcinoma is the most common primary malignancy of the duodenum.
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...
Duodenal atresia results from a congenital malformation of the duodenum and requires prompt correction in the neonatal period. It is considered to be one of the commonest causes of a fetal bowel obstruction.
The prevalence of duodenal atresia is ~1 in 5,000-10,000 newborns, and th...
Duodenal diverticula are outpouchings from the duodenal wall (intraluminal diverticulum discussed separately). They may result from mucosal prolapse or the prolapse of the entire duodenal wall and can be found at any point in the duodenum although are by far most commonly located along the media...
Duodenal diverticulitis (plural diverticulitides) is a rare, inflammatory complication of duodenal diverticula.
While the vast majority of patients are asymptomatic, patients with diverticulitis usually present with epigastric pain, nausea and vomiting.
Duodenal filling defects may be caused by a wide variety of duodenal pathology which may be divided by their location and pathological process.
common bile duct impression
Note: please refer to duodenal mucosal nodular fill...
Duodenal hematoma results in hematoma formation in the duodenal wall. It may occur as a result of blunt abdominal trauma, non-accidental injury to children and spontaneously in anti-coagulated patients.
Distinction must be made from duodenal perforation since the latter will require immediate s...
A duodenal–jejunal bypass liner (DJBL), also known as a duodenal–jejunal bypass sleeve device or EndoBarrier™ is being trialled as a new technique, as an alternative to more 'traditional' gastric bypass surgeries 1,2. The basic principle is that the sleeve is endoscopically-inserted into the duo...
The duodenal switch procedure is a form of biliopancreatic diversion which is often done as a obesity reduction surgery.
It has a restrictive portion and malabsorptive portion
restrictive portion: involves removal of approximately 70% of the stomach (along the greater curvature) and most of th...
Duodenal varices is the dilatation of the posterior superior pancreaticoduodenal vein secondary to portal hypertension. They are much less common than esophageal, rectal or fundal varices, but may be associated with them.
Lobulated filling defects are best de...
A duodenal web, diaphragm or intraluminal diverticulum refers to a complete or incomplete obstruction at the duodenum due to a membranous web or intraluminal diverticulum. There is usually a small aperture at the center differentiating this from a duodenal atresia.
Although they are frequently...
Duodenitis is a term given to inflammation of the duodenum.
A duodenitis can result from both intrinsic processes within the duodenum as well as from processes occuring outside the duodendum. It can occur from infective as well as non-infective inflammatory processes.
The duodenojejunal (DJ) flexure or junction is the anatomical border between the duodenum and the jejunum.
The DJ flexure is located anterolateral to the aorta at the level of the upper border of the second lumbar vertebra. It makes a sharp turn anteroinferiorly to become the jej...
The duodenum is the first part of the small intestine and is the continuation of the stomach.
The duodenum is a 20-30 cm C-shaped hollow viscus predominantly on the right hand side of the vertebral column. It lies at the level of L1-3 and the convexity of the duodenum (called the...
Duplex appendix is a rare anomaly of the appendix and is usually discovered incidentally during surgery for appendicitis.
Duplication of the vermiform appendix is extremely rare. It is found in only 1 in 25,000 patients (incidence ~0.004%) operated on for acute appendicitis. Altho...
Dysphagia refers to subjective awareness of difficulty or obstruction during swallowing. It is a relatively common and increasingly prevalent clinical problem. Odynophagia is the term for painful swallowing.
Fluoroscopy is the mainstay of imaging assessment but manometry can help evaluate the e...
Dysphagia megalatriensis, also known as cardiovascular dysphagia or cardiac dysphagia, is an impairment of swallowing due to esophageal compression from a dilated left atrium.
Presentation is generally with mild dysphagia, although a minority of patients will have dyspha...
Ebola virus disease (EVD) (also known as Ebola hemorrhagic fever (EHF) or simply Ebola) is a viral hemorrhagic disease caused by the Ebola Filovirus. Ebola is an extremely virulent virus with case fatality rates of approximately 70% 1.
First recognized in 1967 after polio vaccine ...
Epstein-Barr virus-associated smooth muscle tumors (EBV-SMT) are rare and encountered in immunocompromised individuals.
These tumors are generally exceedingly rare, and only seen with any frequency in the setting of immunosuppression, particularly in HIV/AIDS patients, but also po...
Ectopic pancreatic tissue, also known as heterotopic pancreatic tissue, refers to the presence of pancreatic tissue in the submucosal, muscularis or subserosal layers of the luminal gastrointestinal tract outside the normal confines of the pancreas and lacking any anatomic or vascular connection...
Ehlers-Danlos syndrome comprises a heterogeneous group of collagen disorders (hereditary connective tissue disease).
There is a recognized male predominance.
Clinically manifests by skin hyperelasticity and fragility, joint hypermobility and blood vessel fr...
Elevated vitamin B12 (also known as hypervitaminosis B12 or hypercobalaminemia) is most important as a diagnostic and prognostic marker for malignant disease 1,3.
Very high serum levels of vitamin B12, following dietary megadosing, does not seem to have any observable deleterious effects 2.
Emphysematous gastritis is a cause of gastric emphysema, and specifically refers to infectious gastritis. It is an uncommon entity with a high mortality rate. In this condition, microorganisms (e.g. Escherichia coli, Clostridium perfringens) produce the gas, which is identified within the stomac...
Emphysematous pancreatitis is an unusual complication of acute pancreatitis caused by necrotizing infection of the pancreas. It is associated with gas-forming bacteria and characterized by the presence of gas within or around the pancreas.
Infection with gas-forming bacteria such as...
Encapsulating peritoneal sclerosis is a rare benign cause of acute or subacute small bowel obstruction. It is characterized by total or partial encasement of the small bowel within a thick fibrocollagenous membrane.
The condition was originally termed abdominal cocoon. The conditio...
Endocrine tumors of the pancreas, also known as pancreatic neuroendocrine tumors (pNET), arise from the pancreatic islet cells and include some distinct tumors that match the cell type of origin.
Pancreatic endocrine tumors have commonly been referred to as "islet cell tumors", re...
Endometriosis affecting the canal of Nuck is an extremely rare site for endometriosis. It is proposed that retrograde implantation of endometrial tissue into patent canal of Nuck could give rise to the condition.
The condition is presented as a painful inguinal swelling. ...
Endoscopic retrograde cholangiopancreatography (ERCP) is a diagnostic and interventional procedure technique using both endoscopy and fluoroscopy for examination and intervention of the biliary tree and pancreatic ducts. It is typically performed by doctors with endoscopic qualifications (e.g. g...
Endoscopic ultrasound (EUS) is a procedure combining the range of endoscopy with the diagnostic abilities of ultrasound. EUS is used in the imaging of the upper GI tract and surrounding structures as well as the respiratory tract (where it is referred to as endobronchial ultrasound, EBUS). A hi...
Enteritis (plural: enteritides) refers to inflammation of the small bowel. When associated with inflammation of the stomach, the term gastroenteritis is used which is usually caused by infection.
Enteroclysis is a gastrointestinal technique designed to provide improved evaluation of the small bowel. The conventional fluoroscopic technique is not widely used since it is somewhat invasive, time and labor intensive, and not particularly pleasant for the patient. The exam also requires a deg...
An enterocutaneous fistula is an abnormal connection between a loop of bowel and the skin. The content of the bowel being released into the skin surface, such as the anterior abdominal wall. They are most commonly occur secondary to abdominal surgery. Other less common etiologies are chronic inf...
An enteroenteric fistula is the formation of a fistula between two parts of the small bowel.
The can result for a number of reasons most commonly with inflammatory bowel disease, in particular Crohn.
Enterovirus 71 is one of the viruses that causes hand-foot-and-mouth disease in children. It is an enterovirus, one of the picornaviruses.
Infection with enterovirus 71 predominantly results in a vesicular rash of the hands and feet that follows a prodrome of symptoms including fever, vomiting ...
Eosinophilic gastroenteritis (EG) is an uncommon disease characterized by diffuse infiltration of any or all layers of gut wall by eosinophils.
Eosinophilic gastroenteritis is an uncommon but not rare disease with slight male predominance. It can affect any age group but usually...
Eosinophilic myenteric ganglionitis is an enteric neuropathy where there is infiltration of the Auerbach plexus by eosinophils. It can be associated with a bowel dysmotility and can result in gastrointestinal pseudo-obstruction.
Epidermolysis bullosa refers to a rare group of genetically determined conditions characterized by blistering of the skin. This can be limited to the soles and palms or extensive whole body involvement.
limited to the mucosa of the gastr...
Epigastric hernias, also known as fatty hernias of the linea alba, occur ventrally through a defect in the linea alba superior the umbilicus.
Shows a midline defect which is usually small with or without herniation...
Epiphrenic diverticula are pulsion diverticula of the distal esophagus arising just above the lower esophageal sphincter, more frequently on the right posterolateral wall.
They are less frequent than traction mid esophageal diverticula but may have more clinical relevance.
Epiploic appendages (or appendix epiploica, plural: appendices epiploicae) are peritoneum-lined protrusions of subserosal fat that arise from the surface of the large bowel.
Epiploic appendages typically measure 1.5 x 3.5 cm but have been reported to measure up to 15 cm in lengt...
Epiploic appendagitis is a rare self limiting inflammatory/ischemic process involving an appendix epiploica of the colon and may either be primary or secondary to adjacent pathology. This article pertains to primary (spontaneous) epiploic appendagitis. The term along with omental infarction is g...
The epiploic foramen (also called the foramen of Winslow) is a passage between the greater (general peritoneal space) and lesser sac (omental bursa), allowing communication between these two spaces.
It has the following borders:
anterior: the free edge of the lesser ...
This is a basic article for medical students and other non-radiologists
Erect chest x-rays are standard positioning but are also a specific examination performed for the assessment of subdiaphragmatic free gas (pneumoperitoneum).
This is a summary article; we do not have a m...
Eructation is the medical term for belching.
Excessive/troublesome belching is most commonly found as a symptom of gastro-esophageal reflux disease. Rarely patients can present with recurrent paroxysms of belching secondary to seizure activity in the brain, this is called ictal eruct...
Esophageal and esophagogastric junction adenocarcinoma staging refers to TNM staging of adenocarcinoma originating in the esophagus or esophagogastric junction (including tumors whose center is within the proximal 2 cm of the gastric cardia). Related histologies included in this system are high ...