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 oesophageal spasm (DOS) is a motility disorder of the oesophagus. On barium swallow, DOS may appear as a corkscrew or rosary bead oesophagus, but this is uncommon. Manometry is the gold-standard diagnostic test.
Diffuse oesophageal spasm differs from hypercontracting oesophagus ...
Diffuse or disseminated peritoneal leiomyomatosis, also known as leiomyomatosis peritonealis disseminata, is an exceedingly rare benign disorder characterised 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 generalised 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.
Outpouchings of bowel result in blind-ended diverticula in communication with th...
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 asymptomatic and acute diverticulitis is a potentially life-threatening illne...
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.
Diverticulum is the singular form and diverticula is the correct Latin plural form. 'Diverticuli' and 'diverticulae' are erroneous and should not be used (cf. septum).
contains all layers of the...
The doge cap sign is a radiographic sign of pneumoperitoneum. It presents as a triangular-shaped gas lucency in the right upper quadrant on abdominal radiographs due to air in the Morison pouch, which resembles the medieval caps worn by Italian doges.
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 oesophagus: oesophageal 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 centres 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 technique is a method of imaging the colon with fluoroscopy. "Double contrast" refers to imaging with the positive contrast of barium sulfate contrast (rarely water-soluble iodinated contrast) as well as with the negative contrast of gas (CO2 preferable). An exam wit...
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 visualise 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 double wall sign is another name for the Rigler sign. It is a sign of pneumoperitoneum with gas outlining both sides of the bowel wall. It is seen when large amounts of free gas, >1000 mL, are present.
It should be distinguished from the false double wall sign which refers to two dilated lo...
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 multi-system manifestations.
According to the world health organisation (WHO), the approximate worldwide inci...
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 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 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 haematoma results in haematoma 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...
Duodenal varices is the dilatation of the posterior superior pancreaticoduodenal vein secondary to portal hypertension. They are much less common than oesophageal, rectal or fundal varices, but may be associated with them.
Lobulated filling defects are best d...
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 centre 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 medial term for painful swallowing.
Fluoroscopy is the mainstay of imaging assessment but manometry can help evaluat...
Dysphagia megalatriensis, also known as cardiovascular dysphagia or cardiac dysphagia, is an impairment of swallowing due to oesophageal compression from a dilated left atrium.
Presentation is generally with mild dysphagia, although a minority of patients will have dysph...
Ebola virus disease (EVD) (also known as Ebola haemorrhagic fever (EHF) or simply Ebola) is a viral haemorrhagic 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 vaccin...
Epstein-Barr virus-associated smooth muscle tumours (EBV-SMT) are rare and encountered in immunocompromised individuals.
These tumours are generally exceedingly rare, and only seen with any frequency in the setting of immunosuppression, particularly in HIV/AIDS patients, but also ...
Ectopic pancreatic tissue (or heterotopic pancreatic tissue) refers to the presence of pancreatic tissue in the submucosal, muscularis or subserosal layers of the luminal gastrointestinal tract which is outside the normal confines of the pancreas and lacking any anatomic or vascular connection w...
Ehlers-Danlos syndrome comprises a heterogeneous group of collagen disorders (hereditary connective tissue disease).
There is a recognised male predominance.
Clinically manifests by skin hyperelasticity and fragility, joint hypermobility and blood vessel fr...
Elevated vitamin B12 (also known as hypervitaminosis B12 or hypercobalaminaemia) is most important as a diagnostic and prognostic marker for malignant disease 1,3. Very high serum levels of vitamin B12 do 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 necrotising 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...
Endocrine tumours of the pancreas arise from the pancreatic islet cells and include some distinct tumours that match the cell type of origin.
Pancreatic endocrine tumours have commonly been referred to as "islet cell tumours", referring to the islets of Langerhans, from which they...
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 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.
inflammatory bowel disease
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 labour intensive, and not particularly pleasant for the patient. The exam also requires a de...
An enterocutaenous fistula is 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 inflam...
An entero-enteric fistula is one formed 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 characterised 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 characterised 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...
An epigastric hernia occurs ventrally through a defect in linea alba superior the umbilicus. It is also known as a fatty hernia of linea alba.
Shows a midline defect which is usually small with or without herniation of omenta...
Epiphrenic diverticula are pulsion diverticula of the distal oesophagus arising just above the lower oesophageal sphincter, more frequently on the right posterolateral wall.
They are less frequent than traction mid oesophageal 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/ischaemic 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 ...
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-oesophageal reflux disease. Rarely patients can present with recurrent paroxysms of belching secondary to seizure activity in the brain, this is called ictal eruc...
Evacuation proctography (defecography) is a fluoroscopic technique to evaluate pelvic floor disorders. The technique traditionally involves fluoroscopy and barium, but an analogous MRI technique has also been developed (see: MR defaecating proctography).
incomplete or obstructed de...
Extramedullary haematopoiesis in the adrenal gland is a rare physiologic compensatory event in many haematologic diseases.
For a general discussion on this subject, please refer to the main article on extramedullary haematopoiesis.
Extramedullary haematopoiesis in the adrenal gla...
Extramural vascular invasion (EMVI) is the direct invasion of a blood vessel (usually a vein) by a tumour. In rectal cancer, this can occur on a macroscopic level and be detected on staging MRI. It is a significant prognostic factor, being a predictor of haematogenous spread.
Extrapulmonary tuberculosis (TB) refers to the haematogenous spread of Mycobacterium tuberculosis.
Extrapulmonary tubercuosis can occur as a primary form of the disease, i.e. direct infection of an extrapulmonary organ without the presence of primary pulmonary tuberculosis or it can ...
Faecal calprotectin (FCAL) is a protein which is a marker of inflammation of the gut used as a diagnostic tool and marker of disease activity for Crohn disease and ulcerative colitis.
Calprotectin is a protein complex from the S-100 family, which is formed of three polypeptide cha...
A faecaloma is a mass of faeces most frequently noted in the rectum and sigmoid colon, that is much harder than a faecal impaction due to coprostasis.
Symptoms are nonspecific and include constipation, abdominal pain, anorexia, nausea or vomiting, overflow diarrhoea, faec...
The falciform ligament is a broad and thin peritoneal ligament. It is sickle-shaped (Latin: "falciform") and a remnant of the ventral mesentery of the fetus.
It is situated in an anteroposterior plane but lies obliquely so that one surface faces forward and is in contact with the peritoneum beh...
The falciform ligament sign, also called the Silver sign, is characterised by the falciform ligament being outlined with free abdominal gas in cases of pneumoperitoneum of a large amount.
It is almost never seen in isolation as, if there is enough free gas to outline the falciform ligament, th...
Familial adenomatous polyposis syndrome (FAPS) is characterised by the presence of hundreds of adenomatous polyps in the colon. It is the most common of the polyposis syndromes.
Familial polyposis coli, attenuated familial adenomatous polyposis and Gardner syndrome are all variants...
The fascial tail sign is the linear extension along the fascia/muscular aponeurosis from a deeper tumour.
It appears as a tail and is best appreciated on MRI, classically seen in desmoid tumours as T2 hypointense bands that progressively enhance particularly on delayed ph...
The fat halo sign refers to a feature seen on CT examination of the abdomen, and represents infiltration of the submucosa with fat, between the muscularis propria and the mucosa. It is characterised by an inner (mucosa) and outer (muscularis propria and serosa) ring of enhancing bowel wall along...
The fat ring sign (also known as a fat halo sign) describes preservation of fat around the mesenteric vessels and around soft tissue nodules on a background of diffuse fat stranding in patients with mesenteric panniculitis or mesenteric lipomas.
This finding may help distinguish mesenteric pan...
Fat stranding is a common sign seen on CT wherever fat can be found. It is most commonly seen in abdomen/pelvis, but can also be seen in retroperitoneum, thorax and subcutaneous tissues. It can be helpful in localising both acute and chronic pathology.
Fat stranding c...
This is a basic article for medical students and other non-radiologists
Fat stranding is a sign that is seen on CT. It describes the change in attenuation of fat around an inflamed structure and is a very helpful signpost for intra-abdominal pathology.
This is a summary arti...
Feline oesophagus also known as oesophageal shiver, refers to the transient transverse bands seen in the mid and lower oesophagus on a double contrast barium swallow.
The appearance is almost always associated with active gastro-oesophageal reflux 2,3 and is thought to be due to cont...
The femoral canal, or the medial compartment of the femoral sheath, is the inverted cone-shaped fascial space medial to the femoral vein within the upper femoral triangle. It is only 1-2 cm long and opens superiorly as the femoral ring. It serves two purposes:
allows the femoral vein to expand ...
Femoral hernias are a type of groin herniation and comprise a protrusion of a peritoneal sac through the femoral ring into the femoral canal, posterior and inferior to the inguinal ligament. The sac may contain preperitoneal fat, omentum, small bowel, or other structures.
The femoral ring is the superior opening of the femoral canal. Its boundaries are:
medial: lacunar ligament
anterior: medial part of the inguinal ligament
lateral: femoral vein within the intermediate compartment of the femoral sheath
posterior: pectineal ligament overlying the pectineus and...
Fetal enteric duplication cysts are enteric duplication cysts presenting in utero.
They result from an abnormal recanalisation of the gastrointestinal tract. They comprise of a two-layer smooth muscle wall and an internal epithelium of a respiratory or intestinal type. These cysts ma...
Fibromuscular dysplasia (FMD) is a heterogeneous group of vascular lesions characterised by an idiopathic, non-inflammatory, and non-atherosclerotic angiopathy of small and medium-sized arteries.
The prevalence is unknown 7. It is most common in young women with a female to male r...
Fibrosing colonopathy a condition characterised by progressive submucosal fibrosis, particularly of the proximal colon. It is associated with high dose lipase supplementation used to treat exocrine insufficiency of the pancreas, such as in treatment for cystic fibrosis.
It is more...
Fishtail pancreas (also known as pancreas bifidum or bifid tail of the pancreas) is a rare anatomical variant of the pancreas produced by a branching anomaly during its development. It is named as such due to the fishtail-like appearance of the pancreas.
It is a rare anatomical an...
The fissure for ligamentum teres sign or extrahepatic ligamentum teres sign is a radiographic sign of pneumoperitoneum. It represents the outline of the ligamentum teres (remnant of an obliterated left umbilical vein) with free abdominal gas in a supine patient, as seen on a plain abdominal radi...
Flatulence is the expulsion of bowel gas (or flatus) from the anal canal.
The average individual expels a wide range of volume of flatus per day, ~200-2500 mL 1.
The bulk of the volume of the gas comprises oxygen, nitrogen, carbon dioxide, hydrogen, and methane. However these gases lack any as...
Fleischner sign can refer to two distinctly separate signs:
Fleischner sign (enlarged pulmonary artery)
Fleischner sign (tuberculosis of ileocaecal junction)
The Fleischner sign (also known as the inverted umbrella sign), refers to a widely gaping, thickened, patulous ileocaecal valve and a narrowed, ulcerated terminal ileum associated with tuberculous involvement of the ileocaecum.
not to be c...
The floating aorta sign refers to displacement of the abdominal aorta away from the vertebral column.
It is a radiographic/CT sign of retroperitoneal masses.
On lateral lumbar spine radiographs, the expected location of the posterior aortic wall is expected to be ≤10 mm ...
Flocculation refers to the breakdown of a barium suspension during a fluoroscopic study.
The small bowel environment eventually separates out a barium suspension, and this can occur during the normal course of a barium study (15 minutes to three hours). When the suspension flocculates, it no lo...
Fluoroscopic nasojejunal (NJT) or nasogastric tube (NGT) insertion is a valuable procedure offered by radiologists in patient care.
The majority of nasogastric tubes are inserted on the ward level and nasojejunal tubes may be placed in theatre at the time of surgery. In difficult cases, inserti...
Foamy oesophagus is an appearance seen on a single contrast barium study in Candida oesophagitis with associated scleroderma/achalasia (stasis).
Pathophysiologic basis of the foamy oesophagus is uncertain. Stasis is a predisposing factor. Foam is produced directly by the fungal organ...
Focussed Assessment with Sonography for Trauma (FAST) scan is a point-of-care ultrasound examination performed at the time of presentation of a trauma patient.
It is invariably performed by a clinician, who should be formally trained, and is considered as an 'extension' of the trauma clinical ...
The football sign is seen in cases of massive pneumoperitoneum, where the abdominal cavity is outlined by gas from a perforated viscus. The median umbilical ligament and falciform ligament are sometimes included in the description of this sign, as representing the sutures.
Which football is use...
The foramina of Morgagni, also known as the sternocostal triangles, are small defects in the posterior aspect of the anterior thoracic wall between the sternal and costal attachments of the diaphragm. The internal thoracic vessels descend through these foramina to become the superior epigastric ...