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.
The appearance of the apple-core lesion of the colon also can be caused by other diseas...
Bowel wall thickening is a useful finding on imaging studies and has a number of different causes.
The reason for bowel wall thickening depends on the underlying aetiology but includes submucosal oedema, haemorrhage, and neoplastic infiltration.
In describing ...
Bulging duodenal papilla is a conical or cylindrical protuberance at the medial aspect of the descending or horizontal duodenum at the site of the sphincter of Oddi. It is a finding on small bowel follow-though (and endoscopy) and has a relatively long differential. On cross-sectional imaging, ...
Colonic strictures can be long (>10 cm) or short.
scirrhous colorectal carcinoma (apple core sign)
post surgical (anastamotic stricture)
scirrhous colorectal carcinoma
inflammatory bowel disease
There are many complications that can occur following gastric banding. It is helpful to divide these into early and late post-surgical complications.
Although the exact mode of presentation can vary depending on the underlying complication common modes of presentation tha...
Complications post optical colonoscopy are most commonly assessed by CT if patients present with abdominal symptoms post colonoscopy. Complications include:
bowel perforation (most common)
lower gastrointestinal haemorrh...
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
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 leukaemia
acute myeloid leukaemia
herpes simplex lymphade...
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...
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 ...
Diffuse colonic nodularity on barium enema or CT colonography has a range of possible aetiologies:
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 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:
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:
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 o...
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.
Foregut duplication cysts are a type of congenital duplication cyst. They are sometimes classified under bronchopulmonary foregut malformations.
Entities classified as foregut duplication cysts include:
other enteric cysts
oesophageal duplication cysts
A gasless abdomen refers to a paucity of gas on abdominal radiography, and the specific cause can usually be identified when the patient's history is known. Common causes include:
small bowel obstruction
Gastric outlet obstruction is a syndrome resulting from mechanical obstruction of stomach emptying.
Gastric outlet obstruction can be due to malignant or benign causes.
adenocarcinoma (second most common 4)
lymphoma (less common than other malignancies a...
Granular mucosal pattern of the oesophagus represents very fine nodularity of the oesophageal mucosal surface. This finding is non-specific and may represent:
reflux oesophagitis (most common)
superficial spreading oesophageal ca...
Haemoperitoneum (plural: haemoperitoneums) is the presence of blood within the peritoneal cavity.
penetrating or non-penetrating abdominal trauma (often with associated organ injury) 1
ruptured ectopic pregnancy
ovarian cyst rupture
aneurysm or pseudoaneurysm rupture
Hepatosplenomegaly is simply the simultaneous presence of a pathologically-enlarged liver (hepatomegaly) and spleen (splenomegaly).
Many, many infections can produce a mild concurrent enlargement of the liver and spleen. This list is by no means exhaustive!
Hiccups (or hiccoughs), medical term singultus (rarely used), are an unpleasant phenomenon, experienced by everyone on occasion, and usually self-limiting. However the much rarer intractable chronic form can be extremely debilitating.
Hiccups are a symptom that has probably been e...
Gastrointestinal manifestations of AIDS are protean and can be broadly divided into opportunistic infections and tumours:
herpes simplex virus (HSV)
primary infection with HIV
HIV-associated neoplasms are numerous and can be broadly divided into two groups:
associated but not AIDS defining malignancies
The development of these malignancies in HIV affected individuals generally implies progression to AIDS 4:
Intestinal failure is when a patient's native bowel is unable to digest and absorb the food, electrolytes, and fluids needed for normal growth and development.
This often includes intractable diarrhoea, weight loss, dehydration, electrolyte imbalance, and malnutrition.
Intra-abdominal calcification is common and the causes may be classified into four broad groups based on morphology:
These are discrete precipitates in a vessel or organ. They are sharp in outline but the density and shape vary but in some cases they may be virtually pathognomonic:...
Intra-abdominal calcification in a neonate can be caused by a number of pathologies that cause calcification within the peritoneal space or within organs.
The commonest cause is meconium peritonitis which is the result of aseptic peritonitis secondary...
Linitis plastica is a descriptive term usually referring to the appearance of the stomach, although the rectum can also be described this way. The appearance is said to be reminiscent of an old leather water-bottle.
The underlying cause is usually a scirrhous adenocarcinoma with diff...
Causes of calcifications in the lower abdomen and pelvis include:
seminal vesicle and ductus deferens calcification
Lower gastrointestinal bleeding usually occurs distal to the ligament of Treitz, and has a wide differential diagnosis:
Malignant oesophageal neoplasms are much more common than benign oesophageal neoplasms, especially if the patient is symptomatic.
oesophageal carcinoma (90%)
oesophageal squamous cell carcinoma (SCC)
oesophageal spindle cell carcinoma
Barium meal has been frequently used to differentiate malignant and benign gastric ulcers:
Features suggesting benign gastric ulcer
outpouching of ulcer crater beyond the gastric contour (exoluminal)
smooth rounded and deep ulcer crater
smooth ulcer mound
smooth gastric folds that reach the...
Maydl hernias are defined as the presence of two small bowel loops within a single hernial sac, that is, there are two efferent and two afferent loops of bowel, forming a "W" shape.
This type of hernia is more prone to strangulation and necrosis. The intervening intra-abdominal loop is also at ...
McBurney point is defined as a point that lies one-third of the distance laterally on a line drawn from the umbilicus to the right anterior superior iliac spine. Classically, it corresponds to the location of the base of the appendix 1.
Clinically, McBurney point is relevant for the elicitation...
Medical devices in the abdomen and pelvis are important to be recognised, just like medical devices of the chest. Often we ignore these devices, considering them to be incidental and non-pathological, however it is essential to be aware of potential complications.
Megaoesophagus or diffuse oesophageal dilatation can be caused by a variety of conditions.
Some of the more common causes are given below 1-3:
malignant stricture, e.g. oesophageal cance...
Mucinous cystic neoplasms of the pancreas are the most common cystic neoplasm of the pancreas and include:
mucinous cystadenoma of pancreas
mucinous cystadenocarcinoma of pancreas
intraductal papillary mucinous neoplasms (IPMN) of the pancreas: sometimes classified separately
Nodular filling defects due to mucosal lesions in the duodenum are due to a number of processes. For a differential list which includes non-mucosal lesions see duodenal filling defects.
The differential diagnosis for mucosal lesions includes:
heterotopic gastric mucosa
Non-neoplastic solid lesions of the pancreas are conditions which may mimic pancreatic neoplasms on imaging. They include:
intrapancreatic accessory spleen
peripancreatic lymph node
Oesophageal dysmotility refers to the pathological disruption of the normal sequential and coordinated muscle motion of the oesophagus to transport food from the oropharynx to the stomach. It is an umbrella term used to refer to the common pathophysiological endpoint of dysmotility that can be c...
Omental cake refers to infiltration of the omental fat by material of soft-tissue density. The appearances refer to the contiguous omental mass simulating the top of a cake. Masses on the peritoneal surfaces and malignant ascites may also be present.
The most common cause is metasta...
Omphalomesenteric fistula occurs as a result of failure of obliteration of the omphalomesenteric duct. It is one of the congenital fistulas of the gastrointestinal tract.
The treatment of choice is often a partial transumbilical resection with umbilical restitution.
Pancreatic atrophy is non-specific and is common in elderly patients, although in younger patients it can be a hallmark of pathology. Most commonly it is associated with ageing, obesity and end-stage chronic pancreatitis.
It occurs principally with fatty replacement of the pancreas (pancreatic...
Pancreatic calcifications can arise from many aetiologies.
Punctate intraductal calcifications
alcoholic pancreatitis (20-40%) 2
intraductal, numerous, small, irregular
preponderant cause of diffuse pancreatic intraductal calcification
gallstone pancreatitis (2%) 2
There are numerous primary pancreatic neoplasms, in part due to the mixed endocrine and exocrine components.
Classification based on function
exocrine: ~99% of all primary pancreatic neoplasms
pancreatic ductal adenocarcinoma ~90-95%
intraductal papillary muc...
Pancreatitis (plural: pancreatitides) refers to inflammation involving the pancreas.
It has various forms which can be classified in many many ways according to time of onset, aetiological agent or associated pathology.
interstitial oedematous pancreatitis
A pantaloon hernia (dual hernia, Romberg hernia or saddle bag hernia) is defined as ipsilateral, concurrent direct and indirect inguinal hernias. Hernial sacs are present on both sides of the inferior epigastric vessels, and separated by the posterior wall of the inguinal canal brought down by t...
Periampullary tumours are those that arise within 2 cm of the ampulla of Vater in the duodenum.
Tumours that fall under this group include four main types of tumours 1,4 that will be approached in their specific articles:
pancreatic head/uncinate process tumours: includes pancreatic ductal ade...
Peritoneal calcification is seen in a limited number of conditions that result in calcification of peritoneal structures. Therefore, the differential diagnosis is small:
psammoma bodies in malignancy (most frequently cystadenocarcinoma of the ovary): fine sand-like calcification
PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET).
PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). Fluorine-18 (F-18) is an unstable radioisotope and has a half-...
Pneumatosis coli is a descriptive sign presenting radiographically as intramural gas limited to the colonic wall.
There are different terminologies in the medical literature, such as pneumatosis intestinalis, pneumatosis coli, and pneumatosis cystoides intestinalis. Pneumatosis in...
Primary peritoneal neoplasms comprise an uncommon group of heterogeneous entities, which include:
primary (malignant) peritoneal mesothelioma
peritoneal multicystic mesothelioma
primary peritoneal well-differentiated papillary mesothelioma
primary peritoneal adenomat...
Primary pneumatosis intestinalis (PPI) is a benign idiopathic condition in which multiple gas-filled cystic lesions are seen in the gastrointestinal tract wall. The changes are usually seen initially on radiography or CT with CT being the more sensitive test.
Primary pneumatosis i...
Pseudopneumoperitoneum describes any gas within the abdominal cavity that masquerades as free intraperitoneal gas or pneumoperitoneum when it is in fact contained within an organ. Correctly identifying pneumoperitoneum is important, but making the diagnosis in error may lead to further unnecessa...
RASopathies are a class of developmental disorders caused by germline mutations in genes that encode for components or regulators of the Ras/mitogen-activated protein kinase (MAPK) pathway.
As a group, RASopathies represent one of the most common malformation syndromes, with an in...
Radiological manifestations of recreational drug use are not infrequently seen as the use of recreational drugs is widespread.
Interestingly, recent reports have suggested a decreasing incidence of reported drug use in the general population over the past decade, but it remains th...
Rectal foreign bodies are not uncommon in emergency departments around the world and potentially cause management difficulties.
The incidence varies according to the region, said to be uncommon in Asia and most common in Eastern Europe 1. Typically patients are male with a wide ra...
Retrorectal developmental cysts are rare and mostly congenital benign lesions found in the retrorectal space:
spectrum of cystic teratomas
retrorectal epidermoid cyst
retrorectal dermoid cyst
retrorectal teratoid cyst
duplication cyst of the rectum
tailgut duplication cyst
Right iliac fossa mass is a common clinical presentation and has a range of differentials that need to be excluded. Radiology plays an important role in this differentiation.
In many centres, laparoscopic Roux-en-Y gastric bypass has become the most common bariatric procedure for morbid obesity.
In this operation, the stomach is stapled or divided to form a small pouch (typically <30 mL in volume), which empties into a Roux limb of the jejunum of varying length (ty...
A Sister Mary Joseph nodule is a metastatic lesion involving the umbilicus. The most common primary source is an intra-abdominal adenocarcinoma.
Umbilical metastases are uncommon, reportedly present in 1-3% of all intra-abdominal and/or pelvic malignancy 7.
Regular, smooth generalised thickening
congestive cardiac failure (CCF)
anticoagulation or bleeding diathesis
IgA vasculitis (Henoch-Schonlein purpura)
Small bowel imaging aims at assessment of the disorders of small intestine.
barium follow through
Small bowel or mesenteric ischaemia may be a life-threatening condition, arising from any one of numerous causes of disturbance of the normal blood flow through the small bowel wall.
It can be divided into acute and chronic forms, with the main underlying aetiologies (each discussed...
Soft-tissue sarcomas are a heterogeneous group of malignant tumours of mesenchymal origin (sarcoma) that originate from the soft tissues rather than bone. They are classified on the basis of tissue seen on histology. The commoner sarcomas in the adult and paediatric population are listed below.
Splenic amyloidosis is rare as an isolated entity. Most often it is associated with either systemic amyloidosis or hepatic amyloidosis.
In general, splenic involvement in amyloidosis is rather frequent (5-10% of cases 6,7).
Symptoms include abdominal mass a...
Splenic calcifications can occur is various shapes and forms and can occur from a myriad of aetiological factors.
The usual calcification observed in radiographs are the multiple, miliary form presenting numerous small rounded densities averaging from three to five millimetres in diameter where...
Splenic epithelial cysts, also referred as splenic epidermoid cysts or primary splenic cysts, are unilocular fluid lesions with thin and smooth walls and no enhancement. They represent ~20% of cysts found in the spleen, and are usually an innocuous incidental imaging finding.
Note that most (~8...
Splenic haemangiomatosis involves multiple, diffuse splenic haemangiomas replacing its entire parenchyma. It is a very rare entity.
It can occur as a manifestation of systemic angiomatosis or, less commonly, confined to the spleen (diffuse isolated splenic haemangiomatosis). There is...
There are a number of splenic lesions and anomalies:
Benign mass lesions
splenic cyst (mnemonic)
splenic haemangioma: commonest benign sp...
Splenomegaly refers to enlargement of the spleen. The upper limit of normal adult splenic length is traditionally cited at 12 cm, but lengths upwards of 14 cm can be seen in normal, taller males 7.
Massive splenomegaly is variably defined, including when the spleen is 5 standard deviations abov...
Spontaneous splenic rupture (SSR) (or atraumatic splenic rupture) is rare, especially when compared to traumatic splenic rupture.
The pathogenesis of atraumatic splenic rupture is not well understood. Splenomegaly is present in almost all patients (~95%), although rupture of normal ...
Sprue is the collective term for the malabsorptive gastrointestinal enteropathies although it may be used to refer directly to tropical sprue. It is composed of two entities:
non-tropical sprue / coeliac disease
In each, the radiologic features are not sensitive enough to confi...
Subdiaphragmatic free gas is one of the ways of detecting presence of free intraperitoneal gas (i.e. pneumoperitoneum). It is the presence of free, extraluminal gas in the anterior subhepatic space.
Subdiaphragmatic free gas is well appreciated as the g...
The differential diagnosis for a terminal ileitis is quite extensive, and includes:
inflammatory bowel disease
Crohn disease (most common)
backwash ileitis due to ulcerative colitis
The small intestine is rarely the site of malignant tumours, although it accounts for ~75% of the entire length of the GI tract and more than 90% of the mucosal surface. Approximately 40 different histologic tumour types have been described.
In this article, an overview will be given of the mo...
An upper gastrointestinal bleed usually refers to bleeding proximal to the ligament of Treitz.
Vertical-banded gastroplasty (VBG) is an older, purely restrictive procedure used to treat morbid obesity.
It involves creating a small gastric pouch, based on the lesser curvature of the stomach (which is thicker and less resistant to stretching than the greater curvature), by using...
A clinical presentation of weight loss is extremely common and often a source of marked anxiety for the patient. The commonest cause of unintentional weight loss (UWI) is gastrointestinal tract disease, and not malignancy.
The published literature lacks a consistent definition of w...
Widening of the presacral space is one of the diagnostic indicators of the diseases involving pelvic pathology and rectal involvement. It is ideally measured on barium studies at the level of S3/4 disc level on lateral radiographs and the normal value of the presacral space is <15 mm in adults....