Presentation1, radiological imaging of barium studies.
Dr/ Abd Allah Nazeer. MD.
Radiological Imaging of barium studies.
Conventional Barium Esophagography (Barium Swallow)
Modified Barium Swallow (Oral and Pharyngeal Function Study)
Diagnosis of Food Impactions & Foreign Bodies in the Esophagus
Upper G.I. Series;
Biphasic-Contrast Examination Using "Bubbly Barium"
Small Bowel Follow-Through
Policy on Doing Barium Enemas Following Endoscopy +/- Biopsy
Types of Barium Enema
Double-Contrast Examination of the Colon
Single-Contrast Examination of the Colon
Water Soluble Contrast Enema
Colon Transit Time (Colonic Motility Test)
Defecography (Evacuation Proctography).
Barium Swallow: The hypopharynx & cervical esophagus
AP and lat, views
of the barium-
of the contrast
to larynx and
This oblique view of a normal barium swallow shows the normal impressions made by
the (A) aortic arch, (B) left main stem bronchus, and (LA) left atrium on the esophagus.
The esophagus is a muscular tube that is normally 25-
30 cm long and 2-3 cm wide. The esophagus is found
anterior to the vertebral column and extends from
approximately C6 down, following the curvature of
the vertebral column. It passes through the
esophageal hiatus of the diaphragm at
approximately T10. The esophagus is divided into
three segments: the cervical, thoracic, and abdominal
segments. The cervical portion is separated from the
cervical vertebrae by only a few mm of prevertebral
There are several structures that are in close
proximity to the esophagus and which make normal
impressions on it. These structures are the aortic arch
at T3-T4, the left main stem bronchus, the left inferior
pulmonary veins and in some normal healthy people
the left atrium, although a large impression is usually
a sign of left atrial disease.
The following are additional diseases and conditions that affect the esophagus:
Acute esophageal necrosis
Caustic injury to the esophagus
Diffuse esophageal spasm
Esophageal atresia and Tracheoesophageal fistula
Jackhammer esophagus (hypercontractile peristalsis)
Esophageal duplication cyst
Esophageal duplication cysts are a type of congenital foregut duplication
Patients are generally asymptomatic but may complain of dysphagia due
to esophageal compression. They typically present in childhood.
It mainly occurs within the thoracic esophagus.
Well defined soft tissue density in close association with the esophagus.
On barium swallow the cyst may cause extrinsic compression of the
Well defined thick walled structure (fluid density) noted along the esophagus.
T1: low to intermediate signal intensity
T2: high signal intensity
Congenital tracheoesophageal (TE) fistulas result from failure of the esophageal lumen to
develop completely separate from the trachea. Embryonically, the trachea and upper GI tract have a
common origin at the caudal end of the embryonic pharynx. In normal development during the second
month of gestation, the esophagus assumes a dorsal position, while the trachea lies ventrally. Failure
of this complete separation leads to the development of TE fistulas. Below is a diagram depicting the
different type of congenital TE fistulas and their frequency of occurrence. Esophageal atresia (EA) is a
common cause of polyhydramnios in utero. At birth, the infant may have difficulty handling secretions
and may have respiratory distress at first feeding. Attempts to pass a nasogastric tube are usually
unsuccessful. Infants with TE fistulas tend to have rounded abdomens and bowel sounds, while those
with EA without a fistula tend to have scaphoid abdomens and absent bowel sounds.
In image "A" we can see atresia of the upper esophagus as evidenced by failure to pass a feeding tube down
the esophagus, but we still observe gas in the abdomen. These findings are likely due to a esophageal atresia
with a distal tracheoesophageal fistula. Images "B, C, D" show contrast filling a blind pouch.
Esophageal atresia with TE
fistula. Contrast was
administered through a G
tube into the stomach. The
contrast refluxed into the
distal esophagus across the
into the trachea and from
the trachea into the
H-type fistula. A,
(arrow) in a 7-day-old boy
with imperforate anus. B,
Demonstration of another H-
type fistula (arrow) from the
upper cervical esophagus to
the trachea, using the
technique of contrast
injection through a feeding
tube with very careful
volume control. C, Large H-
type fistula from the upper
cervical esophagus to the
Connections between esophagus and airway. A, Congenital esophagobronchial
fistula. Oblique view shows esophagus (arrows with 1) and bronchus to right upper
lobe (arrow with 2). B, Esophageal bronchus. Frontal view from an esophagram
demonstrates the origin of the right main bronchus from the distal esophagus.
A Schatzki ring, also called Schatzki-Gary ring, is symptomatically narrow esophageal
B-ring occurring in the distal esophagus and usually associated with a hiatus hernia.
Relatively common, lower esophageal rings are found in ~10% of esophagrams.
Location: Schatzki rings are located at the gastro-esophageal junction. They should
not be confused with A-rings, which are found a few centimeters proximal to the B-
esophageal webs, which are lined on both sides by esophageal mucosa
More than half of patients will have an associated esophageal condition such as:
hiatus hernia, reflux oesophagitis, esophageal web, esophageal diverticulum
Fluoroscopy: barium swallow
Single-contrast solid barium swallows (especially in the RAO prone position) are more
sensitive than endoscopy in detecting Schatzki rings. On barium swallow the
following features may be seen:
full-column barium swallow will reveal a circumferential narrowing at the gastro-
esophageal junction, often a few centimeters above the diaphragmatic hiatus
thin smooth ring, 1-3 mm
double contrast studies are less sensitive
performing a Valsalva manoeuvre may improve sensitivity
barium-tablet or barium-coated marshmallow may also improve sensitivity
The above esophagrams show a Schatzki ring (red arrow) at the distal esophagus.
Esophageal webs refer to an esophageal constriction caused by a thin mucosal
membrane projecting into the lumen.
Esophageal webs tend to affect middle-aged females.
Patients are usually asymptomatic and the finding may be incidental and unimportant.
However, if the stenosis is severe symptoms include dysphagia and regurgitation of food.
More commonly occur in the cervical esophagus near cricopharyngeus muscle than in the
thoracic esophagus. They typically arise from the anterior wall and never from the
posterior wall; they can also be circumferential. Occasionally, multiple webs are visualized
during maximal distension.
GORD/GERD (especially a distal esophagus web)
external beam radiation
Fluoroscopy: barium swallow may be demonstrated on high-volume barium esophagrams
when the esophagus is fully distended a "jet effect" of contrast passing distal to the web
may be seen.
Barium swallow shows
radiolucent ring in
and jet phenomenon
through the ring on
Congenital esophageal web with tight upper esophageal stenosis with
proximal dilatation, hold up of contrast and distal narrowing.
Anterior web (large arrow) and
posterior impression (small arrow)
due to cricopharyngeus spasm.Circumferential web (arrow).Anterior esophageal web (arrow).
Esophageal diverticula are sac or pouch projections arising from the esophagus.
They can occur in all ages but more frequent in adults and elderly people.
Pathology: Esophageal diverticula are either:
true diverticula: include all esophageal layers
false diverticula: contain only mucosa and submucosa herniating through the muscular layer
(e.g. Zenker diverticulum)
Esophageal diverticula are classified according to the mechanism of formation into:
traction diverticula: occurs secondary to pulling forces on the outer aspect of the esophagus
pulsion diverticula: occurs secondary to increased intraluminal pressure (e.g. Zenker
They can be classified according to their location:
Upper esophageal diverticula
Zenker diverticulum: actually pharyngeal but it is common practice to include it with
Middle esophageal diverticula
Traction diverticula: are (true diverticula) which occur secondary to scarring, fibrosis and
inflammatory processes (tuberculous adenitis) in the mediastinum pulling on the esophageal
pulsion diverticula: are usually false diverticula and occur secondary to abnormal increased
intraluminal pressure against a weak esophageal segment
Lower esophageal diverticula
Image "A" depicts the frontal view of a large barium-filled sac (Z) below the level of the hypopharynx.
Image "B" is a lateral view depicting a large Zenker's diverticula (Z) in the posterior cervical esophagus.
Zenker's diverticulum on chest film, barium study and CT.
Image "A" depicts multiple varices on esophagram. Image "B" is an angiographic
demonstration of cavernous transformation of the portal vein (PV) with reversal of blood flow
through the coronary veins (CV) and splenic vein (SV) producing esophageal varices (Var.)
Esophagram depict contrast extravasation from the distal esophagus
in a patient with spontaneous perforation of the esophagus.
CT shows dilated esophagus (arrow) that
led to esophagram. RIGHT: Esophagram
shows narrowing (arrow) at level of hiatus.
Image "A" depicts a lateral view of the esophagus showing a massively dilated esophagus
with retention of contrast in the distal portions of the esophagus. Image "B" shows the
"bird's beak" appearance of the dysfunctional lower esophageal sphincter.
Scleroderma - Barium swallow of patient with scleroderma. Note the dilated esophagus (arrows).
Esophagrams showing the typical "corkscrew" or "beaded"
appearance of diffuse esophageal spasms(DES).
Stricture - Patient with esophageal stricture, with green arrows showing
area of stricture. Note the barium tablet indicated by the red arrows.
Barrett's - Upper GI swallow of patient
with Barrett's esophagus. Arrow points to
new transition point of squamo-columnar
junction. Note the irregularities of the
mucosa inferior to transition point.
Columnar metaplasia of the
esophageal stratified epithelium
and there is a strong association
1- mild esophageal stricture.
2-reticular mucosal pattern.
Canida - Above is a characteristic "shaggy esophagus" associated with Canida infection. Image "A"
depicts the longitudinally oriented plaque-like lesions visible in Candida esophagitis. Image "B" depicts
the granular appearance of the esophageal mucosa secondary to edema and inflammation.
Image "A" and "B" both depict ulcerations of the distal esophageal mucosa secondary to
lye ingestion. Image "C" depicts irregular narrowing of the esophagus with ulcerations.
Gastro-esophageal reflux disease (GERD) is a spectrum of disease that
occurs when gastric acid refluxes from the stomach into the lower end of the
esophagus across the lower esophageal sphincter(LOS).
Minor reflux disease
In most patients with reflux disease, reflux is initiated by transient collapses
of LOS pressure. This results in the lower end of the esophagus being bathed
in gastric acid for longer than normal. Patients may be symptomatic without
developing endoscopic appearances of oesophagitis (40% of cases). These
patients will also have no detectable abnormality on a barium swallow.
Advanced reflux disease
In patients with a permanently low LOS pressure, symptoms are generally
more severe and there is evidence of disease in endoscopic or barium
studies. Abnormalities that are radiologically detectable include:
impaired primary peristalsis and poor clearance
abnormal esophageal contractions
oesophagitis with scarring
strictures, Barrett esophagus and aspiration
sacculations and intramural pseudodiverticula
Ovoid filling defects
caused by the
smooth surface and
A calcified esophageal mass is almost always a leiomyoma.
Esophageal carcinoma is relatively uncommon. It tends to present with increasing
dysphagia, initially to solids and progressing to liquids as the tumour increases in size,
obstructing the lumen of the esophagus.
Many indirect signs can be sought on a chest radiograph and these include:
widened azygo-esophageal recess with convexity toward right lung (in 30% of distal and
mid-esophageal cancers) thickening of posterior tracheal stripe and right paratracheal
stripe >4 mm (if tumour located in the upper third of esophagus)
tracheal deviation or posterior tracheal indentation/mass
retrocardiac or posterior mediastinal mass
esophageal air-fluid level
lobulated mass extending into gastric air bubble (Kirklin sign)
pre-stricture dilatation with 'hold up'
shouldering of the stricture
eccentric or circumferential wall thickening >5 mm
peri-esophageal soft tissue and fat stranding
dilated fluid- and debris-filled esophageal lumen is proximal to an obstructing lesion
tracheobronchial invasion appears as a displacement of the airway (usually the trachea
or left mainstem bronchus) as a result of mass effect by the esophageal tumour
"A" we can see a Schatzki ring (red arrows) and filling defects (yellow arrows) proximal to the ring which
was found to be squamous cell cancer. Images "B" and "C" show the same findings in a close-up view.
Irregular stricture in the esophagus with ulceration of the esophageal mucosa. Also noticed the shouldered margins
of the lesions. CT images, one can see circumferential thickening of the esophageal wall (annular lesion).
"A" the red arrows show mucosal invasion with ulceration, whereas the yellow
arrow points out a stricture at the GE junction. In image "B", we can further see an
irregular filling defect in the distal esophagus associated with adenocarcinoma.
LEFT: Small polypoid carcinoma. RIGHT: Large polypoid lesion.
Esophageal carcinoma with ulcerations (arrows) and sharp right
angle junction with esophageal wall (arrowheads).
Distal narrowing simulates achalasia, but narrowing is eccentric, shoulders are asymmetric
(arrows), and the mucosa is irregular at the tip of narrowing.
CT shows gastric fundus thickening (arrows) due to adenocarcinoma.
Diffuse large B-cell lymphoma of the esophagus. Axial (a) and coronal (b) fused PET/CT images
show a large focus of FDG accumulation in an intraluminal esophageal mass (arrow) and a
smaller focus in the left hilar nodes (arrowhead in b). Primary esophageal lymphoma is rare and
is commonly mistaken for esophageal carcinoma. Biopsy provides the final diagnosis.
Hypertrophic pyloric stenosis (HPS) refers to the idiopathic thickening of gastric pyloric musculature
which then results in progressive gastric outlet obstruction.
Plain radiograph: Abdominal x-ray findings are non-specific but may show a distended stomach with
minimal distal intestinal bowel gas.
Fluoroscopy: An upper gastrointestinal series (barium meal) excludes other, more serious causes of
pathology, but the findings of a UGI series infer rather than directly visualise the hypertrophied muscle.
On upper gastrointestinal fluoroscopy:
delayed gastric emptying
peristaltic waves (caterpillar sign)
elongated pylorus with a narrow lumen (string sign) which may appear duplicated due to puckering of
the mucosa (double-track sign)
the pylorus indents the contrast-filled antrum (shoulder sign) or base of the duodenal bulb (mushroom
the entrance to the pylorus may be beak-shaped (beak sign)
Ultrasound: Ultrasound is the modality of choice in the right clinical setting because of its advantages
over a barium meal are that it directly visualizes the pyloric muscle and does not use ionizing radiation.
The hypertrophied muscle is hypoechoic, and the central mucosa is hyperechoic. Diagnostic
measurements include (mnemonic "number pi"):
pyloric muscle thickness, i.e. diameter of a single muscular wall on a transverse image: >3 mm (most
length, i.e. longitudinal measurement: >15-17 mm
pyloric volume: >1.5 cc
pyloric transverse diameter: >13 mm
With the patient right side down the pylorus should be watched and should not be seen to open.
Described sonographic signs include:
antral nipple sign, cervix sign, target sign.
Elongation and narrowing of the pyloric canal (2-4 cm in length)
String Sign: Passage of small contrast through the narrowed pyloric channel
Crowding of mucosal folds in pyloric channel producing a double or triple track sign
Hypertrophic pyloric stenosis.
Ultrasound views of the stomach and pylorus in a 5-week-old boy with
gastric distention as evidenced by hyperechoic gas in a fluid-filled stomach
(A; arrow) and pyloric lengthening (B; arrow) and thickening (C; arrow).
Abdominal plain radiograph (A)
and UGI series (B) in a 4-week-old
boy demonstrating gross gastric
dilatation (arrows) and a bird-beak
appearance to the gastric outlet.
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 there
is no sex-associated difference in prevalence.
Abdominal radiographs may classically show a double bubble sign with gas
filled distended stomach and duodenum with an absence of distal gas. A
similar appearance (either filled with fluid or gas) can be seen in other
Distal bowel gas although more classically associated with duodenal stenosis,
however, it can be seen in duodenal atresia via anomalous bile duct anatomy.
May also show a dilated stomach and duodenum giving a double bubble type
appearance. This, however, may not be sonographically detectable until the
mid to late second trimester. May also show evidence of polyhydramnios as
an ancillary sonographic feature.
Abdominal examination showed a uterus
size that is more than the gestational age
calculated from the LMP.
Ultrasound showed "double bubble sign"
“Double bubble" sign (dilated stomach and duodenal bulb) -- dilated stomach and no gas distal to the
proximal duodenum. Stated another way, there is no gas in the rest of the small or large bowel.
Duodenal atresia and web. A) Typical double-bubble
appearance of gastric and duodenal airs (arrow) is
well depicted on erect plain film in a case with
duodenal atresia. B) Second portion of duodenum is
partially obstructed by web (arrow) on barium study in
Duodenal diverticula are outpouchings from the duodenal wall. 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 medial wall of the second, or superior wall of
the third part of the duodenum.
Diverticula located at the ampulla of Vater may cause difficulty for endoscopists as they attempt to
cannulate the biliary system.
Duodenal diverticula are very common, found in up to 23% of asymptomatic patients, and in the vast
majority remain asymptomatic throughout life. In 10% of patients, some symptoms are attributable to
them, with only a minority requiring surgical intervention.
Pathology: There are a two of types of duodenal diverticula: primary and secondary diverticulum
A primary duodenal diverticulum occurs where there is prolapse of mucosa through the muscularis
propria. They usually occur within the 2nd part (62%) and less commonly in the 3rd (30%) and 4th (8%)
parts. Unlike secondary diverticula they are rarely seen in the 1st part. When they occur in the 2nd part,
most (88%) are seen on the medial wall around the ampulla, 8% are seen posteriorly and 4% on the
A secondary duodenal diverticulum results from prolapse of the entire duodenal wall and almost
invariably occurs in the 1st part of the duodenum. These are true diverticula and are usually secondary
to duodenal or periduodenal inflammation, such as from previous ulcer disease.
Location specific sub types
Diverticulae are seen as saccular outpouchings from the duodenum that may contain gas, fluid, contrast
or food debris or any combination of these. They often contain a air-fluid or air-contrast level.
Intraluminal duodenal diverticulum with acute pancreatitis. (a) Upper gastrointestinal series image
shows a contrast-filled intraluminal duodenal diverticulum with the “windsock” appearance
(arrowhead). Oblique coronal reformatted image shows a debris-filled “windsock” intraluminal
diverticulum (arrowheads) distorting the pancreas and the second and third portions of the duodenum.
Intraluminal duodenal diverticulum with situs anomaly with hematochezia. (a) Coronal reformatted
contrast-enhanced CT image shows two intramural diverticula with “windsock” appearance (arrows)
in the 3rd and 4th portion of the duodenum.
Duodenal diverticulum in 45-year-old woman. Axial CT
scan obtained with IV and oral contrast materials at
level of pancreatic head shows 10-mm cystic process
with curvilinear area of increased attenuation (long
arrow) that was initially thought to represent
intraductal papillary mucinous tumor. Short arrow
identifies duodenum. Spot radiograph from upper
gastrointestinal barium series shows characteristic
appearance of duodenal diverticulum (arrow).
Duodenal diverticulum. Coronal T2-weighted MR image obtained with HASTE sequence
shows 15-mm cystic process (long arrow) in region of pancreatic head. Main pancreatic
duct (short arrow) and common bile duct (arrowhead) are shown entering cystic process.
This finding was initially thought to represent nonspecific cystic pancreatic neoplasm.
Extraluminal diverticulum (arrow) is typically shows a fluid-air level in medial wall
of descending duodenum (D) beneath the pancreatic head on CT images. Double-
contrasted barium study of the same case confirms the diverticula (arrow).
Transient duodenal hernia. CT shows A) Herniated small bowel loops (arrows) in the left upper quadrant, B)
The engorged mesenteric vessels (arrow) towards the entrance of the hernia sac. C) Regression of the hernia
sac on follow-up CT and D) regression of the engorged mesenteric vessels on follow-up CT.
Left paraduodenal hernia with abdominal pain. Contrast-enhanced CT shows a sac-like bowel loop (arrows)
in the left paraduodenal fossa. Note anterolaterally displaced inferior mesenteric vein (arrowhead).
Annular pancreas. Fluoroscopy
demonstrates concentric narrowing of
the second portion of the duodenum.
Annular pancreas is a rare congenital abnormality in
which a ring of pancreatic tissue encircles the duodenum at or
above the major papilla. Embryologically it is a sequelae of a
persistent left ventral bud, which usually atrophies during
embryological development. Plain films may demonstrate
proximal small bowel obstruction.
Fluoroscopy more clearly delineates the abnormality. It will
show dilatation of the proximal duodenum, with eccentric or
concentric narrowing of descending duodenum. In the most
severe cases, mucosal effacement will be seen. Note that there
is NO ulceration or mucosal destruction, differentiating it from
neoplastic or inflammatory etiologies.
CT is beneficial for diagnosis confirmation, as it will
demonstrate the ring of pancreatic tissue surrounding
and compressing the duodenum.
Annular pancreas with repeated episodes of vomiting. (a) Coronal thick-slab single-shot MRCP shows
aberrant pancreatic duct (arrow) encircling the descending portion of the duodenum with dilatation
of the proximal duodenum (*). Note mild dilatation of main pancreatic duct (arrowhead).
SMA syndrome: Note the dilated duodenum (D)
with abrupt caliber change at D2/3 portion
caused by compressive effects of SMA
SMA syndrome: CT scan of the same patient
showing duodenal obstruction (long arrow)
at the level of SMA (short arrows).
Gastrointestinal stromal tumor (GIST). A solid and
heterogeneously enhanced tumor (arrows) with
smooth contours located on duodenum partially
obliterates the lumen on CT scan. Concentrically
narrowed duodenal lumen (arrows) with “apple
core” appearance is seen on barium study.
Duodenal adenocarcinoma. A) US demonstrates pseudo kidney appearance of duodenal
mural thickening. B) CT scan confirms concentric duodenal mural thickening and C) barium
study also reveals irregular mucosal filling defects and mild dilation of duodenal genu.
Duodenal lymphoma. Non-contrast (A) and contrasted (B) CT scans show narrowed lumen
and concentrically thickened horizontal portion of duodenum (arrows). C) US image
demonstrates pseudo kidney appearance (arrow) of duodenal wall thickening. D) Barium
study also reveals narrowed and irregular mucosa pattern (arrows) of horizontal duodenum.
Gastritis. Note the pronounced thickening of rugal folds throughout the stomach.
Acute gastritis with Thickened gastric rugae (> 5mm) secondary to edema
Antral narrowing (indicative of h. pylori)
Erosions: manifest by small mucosal defects that collect contrast
Axial (A) and coronal (B) contrast-enhanced CT in a 56-year-old woman with diffuse gastric
mucosal thickening (arrows) caused by Antral gastritis. The fundus is relatively normal.
Coronal CT with soft tissue windows (A) and lung window settings (B) in a 67-year-old
diabetic woman with mural gastric gas (arrow) due to emphysematous gastritis.
A featureless stomach due to atrophic gastritis. There is also a small antral polyp (arrow).
Barium study from a patient with known Crohn's shows a serrated appearance
of the antrum (arrows) due to inflammatory involvement from Crohn's.
Gastric (peptic) ulcers can be detected on multiple imaging modalities,
but are best evaluated on a double contrast barium upper GI study.
The classic appearance for a benign gastric ulcer on a double contrast
study is >2 mm oval mucosal defect (a "crater")
Thin gastric folds radiating toward the crater
There are however, multiple different appearances that an ulcer may take,
including a linear shape or a serpentine shape. Mucosal defects <2 mm are
Ulcers are often associated with a ring of edema around the ulcer crater,
which can give rise to a thin radiolucent "waist" to the ulcer crater. This
has been termed a Hampton line, ulcer collar, or ulcer mound, as
increasing amounts of edema are present.
The vast majority (90-95%) of gastric ulcers are located on the lesser
curvature and posterior stomach wall in the gastric body and antrum.
They are uncommonly on the greater curvature (~5%).
UGI series in a 44-year-old man with thickened antral folds and a punctate
collection of barium at the center (arrow) due to an antral ulcer.
UGI series in a 76-year-old woman with
a larger benign lesser curve ulcer (arrow).
Large benign lesser curve ulcer (large arrow) with
uniform fold convergence on the ulcer (small arrow).
Benign gastric ulcer. prominent radiating folds extend directly to the ulcer.
Barium meal demonstrates a giant gastric ulcer in profile. It is arising from the
greater curvature of the pyloric antrum, has a deep but smooth ulcer crater,
protrudes beyond the expected gastric contour, and has a prominent ulcer mound.
Upper GI series showing the differences between a malignant and benign gastric ulcer. Left
panel: Malignant gastric ulcer of the distal lesser curvature. There is the biconvex meniscus sign
with a nodular ulcer mound (arrow). Right panel: Benign gastric ulcer of the lesser curvature.
The ulcer crater has smooth margins and projects beyond the gastric wall (arrow).
• 2-3 times more frequent than gastric ulcers
• 3:1 male: female ratio
• Excessive acidity in duodenum from, Abnormally high gastric secretion, Inadequate
• Steroids, Severe head injury, Post-surgical, COPD.
• Bulbar (95%)
• Anterior wall– 50%, • Posterior wall– 23%
• Inferior fornix– 22% • Superior fornix– 5% Post bulbar (3-5%)
• Majority on medial wall just proximal to ampulla, Tendency for hemorrhage in 66%
• Male: female ration 7:1
• Small round, ovoid or linear crater
• Kissing ulcers–ulcers opposite from each other on the anterior and posterior walls
• Giant duodenal ulcer–>3cm (rare) with higher morbidity and mortality
• May be mistaken for the duodenal bulb itself and missed
• Clover-leaf deformity–healed central ulcer of the bulb with four-leaf clover-like deformity
• Hemorrhage 15% melena>hematemesis
• Perforation <10% anterior>posterior /may fistulize to GB
• Obstruction 5%
• Penetration <5% walled-off perforation
Duodenal Ulcer. There is a collection of barium on the dependent surface of the duodenal bulb (white arrows)
on this double contrast (air-contrast) upper GI examination. This represent barium in an ulcer crater.
UGI series in a 72-year-old man with a paraesophageal hernia (arrow). The GE junction lies below the diaphragm.
Hiatus hernias (HH) occur when
there is herniation of abdominal
contents through the esophageal
hiatus of the diaphragm into the
The most common content of a hiatus
hernia is the stomach. There are two
main types of hiatus hernia (although
they may co-exist):
sliding hiatus hernia (>90%)
rolling (para-esophageal) hiatus
Coronal (A) and axial (B) CT in a 47-year-old woman with a sliding hiatal hernia.
GI series and axial contrast-enhanced CT in a 44-year-old woman with both a paraesophageal (large
arrows) and sliding hiatal hernia (small arrows). The GE junction lies below the diaphragm.
UGI in a 54-year-old man with a lesser curve smooth mucosal
filling defect (arrow) due to a gastric adenomatous polyp.
Gardner syndrome and multiple gastric adenomatous polyps.
A. UGIS double contrast study. The arrows
outline the area of irregular mucosa which
was caused by an invasive gastric carcinoma.
B. Single contrast study from the same patient
showing the apple core appearance of the stomach
due to the invasive gastric adenocarcinoma.
UGIS demonstrates luminal narrowing,
wall thickening, and rigidity.
Rugal fold effacement.
Mucosal nodularity or ulceration.
Mets - Patient with metastatic breast cancer with stomach lining infiltration. Note the enlarged diameter of the wall (arrows).
Leiomyoma of the stomach(GIST). Leiomyosarcoma of the stomach(GIST).
A smooth, rounded submucosal mass
(arrow) that proved to be a benign GIST.
Axial (A) and coronal (B) CT in a 44-year-old man
with a smooth intraluminal submucosal filling
defect at the gastric fundus (arrows) due to a GIST.
A CT image of a well-defined GIST confirmed by pathology.
There is no apparent central necrosis and the tumor is not
enhancing because only oral contrast was given.
Axial (A) and coronal (B)
CT in a 55-year-old
woman with a
transmural gastric mass
with ulceration (arrows)
due to a benign GIST.
Gastric dilatation without
evidence of obstruction
linear streaks of gas
within the stomach wall.
UGI series (A) and coronal CT (B) in a 59-year-old woman with an organoaxial
volvulus. The greater curvature (large arrow) is superior (cephalad) and the lesser
curvature inferior (small arrow). The GE junction is indicated by the arrowhead.
Perforated gastric volvulus (mesenteroaxial type) with emphysematous gastritis with abdominal pain.
Zollinger-Ellison syndrome (ZES) is a clinical syndrome that occurs secondary to a
gastrinoma. (Hypervascular pancreatic mass with multiple peptic ulcer and thickened
Diagnosis of ZES is often delayed by 5-7 years after the onset of symptoms.
Gastrinomas are usually multiple and typically located in the duodenum (more
common) or pancreas (less common). These tumours secrete gastrin that results in
hypersecretion of gastric acid, which in turn results in diarrhea, gastritis, severe
gastro-esophageal reflux disease and peptic ulcer disease.
multiple endocrine neoplasia (MEN) type 1: ZES occurs when gastrinoma is functional
On double-contrast upper gastrointestinal studies the following features may be seen:
Thickened rugal folds
Multinodular gastric contour
Erosions and ulcers, especially in atypical locations
Barium may be diluted by the high volume of fluid in the stomach
CT: negative contrast may be used to distend the stomach
thickened rugal folds
multiple gastric nodules/masses
Marked hypervascularity and
thickening of the gastric wall image.
Multiple liver metastases are
present image. The serum gastrin
levels were strikingly elevated,
confirming ZES, though the
gastrinoma was not identified on CT.
A, Axial contrast-enhanced CT in a 70-year-old man with diffuse gastric mucosal thickening due
to Zollinger-Ellison syndrome (arrow). B, A 4-cm pancreatic tail gastrinoma is present (arrow).
Jejunal-ileal atresia is a segmental atresia of the jejunum or the ileum. It is
associated with malrotation and volvulus (25%) and cystic fibrosis (10%).
Patients present within the first days of life with vomiting or a distended abdomen.
Multiple distended loops of bowel.
Barium enema demonstrates unused microcolon
in a patient with distal ileal atresia.
Midgut volvulus in a 68-year-old man with acute abdominal pain. (a) Contrast-
enhanced CT shows superior mesenteric vein (arrow) lying to the left to the
superior mesenteric artery (arrowhead) (reversal of the normal relationship
between superior mesenteric artery and superior mesenteric vein).
Whirl sign associated with postoperative adhesion in a 55-year-old man who
underwent small bowel resection due to traumatic injury 22 years earlier. Axial
contrast-enhanced CT shows the “whirl appearance” (arrows) around the superior
mesenteric artery. Note normal position of the ascending and descending colon.
Small Bowel Obstruction
Radiographic - Plain Film
Distended loops of bowel
Valvulae conniventes are present
Variable amount of gas in colon depending on severity and
duration of obstruction
Gasless abdomen will be seen if distended loops are fluid-
Erect / Lateral Decubitus Plain Film
"String of pearls" sign from small collections of air
Differential levels - air-fluid levels are at different heights
Closed-loop obstruction - entrapment of a loop of bowel by
obstruction (can occur with adhesions, hernias, volvulus)
Small bowel obstruction secondary to adhesions.
Note the linear impression at the site of obstruction.
Adynamic ileus in scleroderma, manifest as diffuse
dilatation. Note the pseudo-diverticula and
featureless pattern of the loops of small bowel.
Diffuse dilatation of loops in chronic
idiopathic intestinal pseudo-obstruction.
Upright abdominal radiograph demonstrates air-fluid levels and small bowel dilatation.
Supine abdominal plain film demonstrates dilated loops of small bowel.
Focal ileus - Abdominal x-ray of patient with focal ileus associated with pancreatitis.
Intussusception occurs when one segment of bowel is pulled into itself or a
neighboring loop of bowel by peristalsis. It is also known as bowel telescoping
It is an important cause of an acute abdomen in children and merits timely
ultrasound examination and reduction to preclude significant sequelae including
Intussusception can occur essentially anywhere. In adults, no such distribution is
present as in the vast majority of cases a lead point lesion is present, and thus the
location will depend on the location of that lesion. In children there is a strong
predilection for the ileocolic region:
ileocolic: most common (75-95%), presumably due to the abundance of lymphoid
tissue related to the terminal ileum and the anatomy of the ileocecal region
ileoileocolic: second most common
ileoileal and colocolic: uncommon
gastric intussusception: rare, but documented.
Abdominal x-rays may demonstrate an elongated soft tissue mass (typically in the
upper right quadrant in children) with a bowel obstruction (and therefore air-fluid
levels and bowel dilation) proximal to it. There may be an absence of gas in the
distal collapsed bowel.
Ultrasonography has a false-negative rate approaching zero and is a reliable screening tool for
children at low risk for intussusception. Children with classic findings of intussusception, however,
need to be investigated with contrast enema, which is both diagnostic (the gold standard in the
diagnosis of intussusception) and therapeutic.
Ultrasound signs include:
target sign (also known as the doughnut sign)
crescent in a doughnut sign
A contrast enema remains the gold standard, demonstrating the intussusception as an occluding mass
prolapsing into the lumen, giving the "coiled spring” appearance (barium in the lumen of the
intussusceptum and in the intraluminal space). The main contraindication for an enema is a perforation.
CT: Has become the modality of choice for assessment of acute abdomen in adults, and thus most
frequently images intussusception. Also, short length transient intussusception is a frequent incidental
The appearance of intussusception on CT is characteristic and depends on the imaging plane and where
along the bowel, the images are obtained.
Best known is the so-called bowel-within-bowel configuration, in which the layers of the bowel are
duplicated forming concentric rings (CT equivalent of the ultrasonographic target sign) when imaged
at right angles to the lumen, and a soft tissue sausage when imaged longitudinally
At the proximal end of the intussusception, there will be two concentric enhancing/hyperdense rings,
formed by the inner bowel and the folded edge of the outer bowel. As one images further along the
intussusception the mesentery (fat and vessels) will form a crescent of tissue around the compressed
innermost lumen, surrounded by the two layers of the outer enveloping bowel. Even further distally the
lead point (if present) will be visualized.
A: Barium enema reveals the intussusceptum in the transverse colon (arrow).
B: With further pressure the intussusceptum is reduced into the ascending colon.
Intussusception. A, A 3-month-old boy with intussusception. A transverse ultrasound image through the
intussusceptum complex shows the donut or target sign, with intussusceptum composed of small bowel,
nodes, and mesentery surrounded by the intussuscipiens. B, A longitudinal section of intussusception in the
same patient as depicted in part A. The image shows the terminal end of the intussusception, with the inner
and outer sleeves of the intussusceptum (white arrows) containing the intussuscepted mesentery (M). Black
arrows outline the outer edge of the intussuscipiens. Note that no lead point is present.
Intussusception. CT demonstrates edematous bowel wall with a target appearance. The
intussusceptum forms the inner part of the bull’s eye, while the intussuscipiens forms the outer layer.
Coeliac disease, also known as non-tropical sprue, is a T-cell mediated autoimmune chronic gluten intolerance
condition characterized by loss of villi in the proximal small bowel and gastrointestinal malabsorption (sprue).
It should always be considered as a possible underlying etiology in cases of iron deficiency anemia of uncertain
Many patients have a paucity of symptoms with no GI upset. However, abdominal pain is considered the most
common symptom. Other manifestations include:
iron deficiency anemia and guaiac-positive stools
Diarrhea, constipation, malabsorption, including fat-soluble vitamins and weight loss.
Features of small bowel barium studies are not sensitive enough for confident diagnosis, but the following
changes may be seen:
small intestinal dilatation due to excess fluid
dilution of contrast
multiple non-obstructing intussusceptions
jejunoileal fold pattern reversal
Features present on CT enteroclysis may include:
jejunoileal fold pattern reversal: thought to have the highest specificity is considered the most discriminating
independent variable for the diagnosis of uncomplicated coeliac disease
ileal fold thickening
prominent mesenteric lymph nodes may cavitate with a fluid fat level
submucosal fat deposition in long standing cases.
Small bowel follow-through in a patient with celiac sprue. Initial imaging (left)
demonstrates mild dilatation and “jejunalization” of the ileum. Subsequent imaging at 30
minutes (right) demonstrates a rapid transit time, with barium dilution and flocculations.
Findings of malabsorption at
(a) Image shows duodenitis
with nodularity in a fold-free
(b) Image shows flocculation
(within oval at upper right),
dilution (single arrow), and
dilatation (double arrow).
(c) Image shows moulage
(within oval), which is a
featureless bald appearance
of the jejunum caused by
atrophy of folds and wall
edema. (d) Image shows
reversal of the fold pattern
(within oval), with more
prominent folds in the ileum
than in the jejunum.
Meckel's diverticulum is the failed obliteration of intestinal end of omphalomesenteric duct,
a finding reportedly present in 2-3% of autopsies. This true diverticulum (containing all three
bowel wall layers) is found 40-150 cm proximal to ileocecal valve, within the ileum. Clinical
presentation is variable, and symptomatology can arise in children or adults. 50% contain
heterotopic mucosa (usually gastric), and the most common adult manifestation is ulceration
and bleeding. In children, SBO (usually from intussusception), pseudoappendicitis (diverticulitis),
or rarely, perforation, can also occur.
Plain films are nonspecific and include distal SBO, sentinel loop in the right lower quadrant, or
occasionally, enteroliths within the diverticulum.
Fluoroscopy is a more sensitive evaluation for Meckel's diverticulum. It usually presents as a
contrast-filled outpouching containing a triangular fold pattern or rugae. With intussusception,
a polypoid filling defect can be observed projecting into the bowel lumen. When a Meckel's
diverticulum presents as bleeding, an ulcer can occasionally be found.
Technetium-99m pertechnetate selectively localizes to gastric mucosa. Because a large
percentage of Meckel's diverticula contain gastric mucosa, Tc-99m pertechnetate can be an
effective means of evaluation. The study is dubbed a "Meckel's scan". A positive test entails a
"hot spot" of increased activity, usually in the right lower quadrant. Note, however, that
because only 50% of Meckel's diverticula contain gastric mucosa, a negative Meckel's scan does
not exclude the diagnosis.
Prone and supine radiographs of the right side of the abdomen obtained during an upper GI barium
series in a 13-year-old boy shows the terminal small bowel and a Meckel diverticulum (arrow).
Meckel's Diverticulum. Reflux into the small bowel has occurred during a single-contrast barium enema
examination. Black arrow points to Meckel's diverticulum arising from small bowel near terminal ileum.
A 36-year-old female with
chronic diarrhea and
abdominal pain. Axial CT
examination shows a
(arrow) within the pelvis
continuous with the bowel.
Post-operatively, this was
found to be a mucocele of
the Meckel's diverticulum.
The patient also had
Crohn's disease with bowel
wall thickening involving
the large bowel (*).
asymptomatic male with
staging CT for lymphoma.
enhanced CT image
showing the Meckel's
diverticulum as a tubular
structure arising from the
antimesenteric border of
the ileum pointing in the
pelvis (white arrow).
A 19-year-old male with painless rectal bleeding. 99mTc-pertechnetate scintigraphy
showing uptake (arrows) of ectopic gastric mucosa in a Meckel's diverticulum.
Peutz-Jeghers syndrome with multiple small bowel polyps, mainly located in jejunum.
Patient with Peutz-Jeghers
syndrome with ileal polyp as
lead point for intussusception.
SBFT (left ) demonstrates a linear filling defect
(arrows). Enteroclysis (right) shows multiple
long, tubular filling defects (arrow).
Acute radiation enteritis with regular fold thickening and effacement.
Mesenteric ischemia. Note the separation of small bowel loops and fold thickening from edema.
Mesenteric neoplasm causing small bowel ischemia. Separation
of loops caused by wall edema. Note also diffuse fold thickening.
Shock bowel represents an ischemic insult to the intestines resulting from
decompensated hypovolemic shock. As a result, the bowel becomes dilated and
fluid-filled. The bowel walls become edematous and thickened, with marked
enhancement on CT. Shock bowel is usually associated with significant ischemic
injuries to other vital organs, and it carries a high mortality.
Crohn's disease is an idiopathic inflammatory bowel disease (IBD) characterized
by widespread gastrointestinal tract involvement typically with skip lesions.
Features on barium small bowel follow-through include:
mucosal ulcers, aphthous ulcers initially
deep ulcers (more than 3mm depth)
longitudinal fissures, transverse stripes
when severe leads to cobblestone appearance
may lead to sinus tracts and fistulae
pseudodiverticula formation: due to contraction at the site of ulcer with ballooning
of the opposite site
string sign: tubular narrowing due to spasm or stricture depending on chronicity
fat halo sign, comb sign
bowel wall enhancement
bowel wall thickening (1-2 cm) which is most frequently seen in the terminal ileum
strictures and fistulae
mesenteric/intra-abdominal abscess or phlegmon formation
abscesses are eventually seen in 15-20% of patients
PA proven hemangioma: coronal T1 FS post contrast and coronal
T2 show enhancing well defined intraluminal jejunal mass.
Burkett’s lymphoma. Enteroclysis (left) demonstrates separation of bowel loops
with irregular fold thickening and luminal narrowing. CT (right) of the same
patient confirms the presence of a large cavitary mass in the left abdomen.
Small intraluminal mass in the ileum (yellow arrow). Associated spiculated
mesenteric mass with adjacent desmoplastic reaction in small bowel carcinoid.
Metastatic melanoma. Note the multiple large filling defects of varying size and shape.
Ulceration. This image demonstrates barium pooling in the base of an ileal ulceration. The atypical
location of this ulcer should raise the suspicion for something other than an uncomplicated ulcer.
Other complicating features include luminal narrowing and fold thickening.
Approximately 20% of patient visits to the emergency department for non-traumatic acute
abdominal symptoms are related to the appendix. In fact, appendicitis is the most
common reason for emergency abdominal surgery in the young adults and especially in the
pediatric population. Therefore it is important to be able to quickly and correctly identify
pathology of the appendix and treat it.
Appendiceal obstruction leads to venous and lymphatic obstruction producing an
edematous, inflamed appendix. The resulting ischemia and mucosal breakdown allows
bacteria to invade the appendix wall. Gangrene with rupture and peritonitis may ensue.
Migration of pain from periumbilical region to RLQ.
Right lower quadrant pain or pain at McBurneyâs point.
Rebound tenderness at McBurneyâs point.
Leukocytosis with leftward shift.
Can also have some hematuria secondary to ureteral inflammation.
Most often diagnosed clinically, imaging can help in atypical of equivocal cases.
Abdominal ultrasound showing an
elongated, blind ended tube. Highly
suspicious for appendicitis.
Abdominal CT demonstrating a fluid filled
appendix, surrounded by an appendiceal
abscess(fluid around the appendix
surrounded by an enhancing rim).
Abdominal CT showing a cystic lesion in the expected region of the appendix. A second
image from the same patient shows mural calcifications within the lesion. This is
highly suggestive of a mucocele from a mucinous adenocarcinoma(although pathology
on this patient revealed this lesion to actually be a mucinous cystadenoma).
Barium meal x ray shows elongated opacified appendix with multiple
Distal filling defects, related to chronic appendicitis.
Microcolon: Barium enema
typical microcolon. This can
be secondary to meconium
ileus, ileal/ jejunal atresia
or Hirschsprung's disease.
Meconium ileus: Supine abdominal radiograph showing
Multiple dilated loops of small bowel. Soap bubble
appearance of meconium mixed with gas (arrow) noted
in Right side of abdomen. Note the absence of air fluid
level despite distal intestinal obstruction.
Meconium ileus is caused by thick,
tenacious meconium that adheres to
the wall of the small bowel and
causes obstruction most often at the
level of the ileocecal valve in a
neonate. Almost all patients with
meconium ileus have cystic fibrosis;
10-15% of CF patients present with
meconium ileus. Complications
include ileal atresia and/or stenosis,
volvulus, perforation, and meconium
peritonitis (due to obstruction and
ischemia from tenacious meconium).
It can be treated nonsurgically with
water-soluble enemas to relieve the
obstruction or be treated surgically.
within the distal
Hirschsprung disease is the most common cause of neonatal colonic
obstruction (15-20%). It is commonly characterized by a short segment of
colonic aganglionosis affecting term neonates, especially boys.
The condition typically presents in term neonates with failure to pass meconium in
the first 1-2 days after birth, although later presentation is also common. Overall
~75% of cases present within six weeks of birth 4, and over 90% of cases present
within the first five years of life.
A definitive diagnosis requires a full thickness rectal biopsy.
Hirschsprung disease is characterized by aganglionosis (absence of ganglion cells)
in the distal colon and rectum. It can be anatomically divided into four types
according to the length of the aganglionic segment:
short segment disease: ~75% *
rectal and distal sigmoid colonic involvement only
long segment: ~15%
typically extends to splenic flexure / transverse colon
total colonic aganglionosis: ~7.5% (range 2-13%)
occasional extension of aganglionosis into the small bowel
ultrashort segment disease
3-4 cm of internal anal sphincter only.
Findings are primarily those of a bowel obstruction. The affected bowel is of
smaller calibre and thus depending on the length of segment affected variable
amounts of colonic distension are present.
In protracted cases marked dilatation can develop, which may progress to
enterocolitis and perforation.
A carefully performed contrast enema is indispensable in both the diagnosis of
Hirschsprung disease but also in assessing the length of involvement. It should be
noted however that the depicted transition zone on the contrast enema is not
accurate at determining the transition between absent and present ganglion cells.
The affected segment is of small calibre with proximal dilatation.
Fasciculation/saw-tooth irregularity of the aganglionic segment is frequently seen.
Views of particular importance include:
early filling views that include rectum and sigmoid colon allowing for rectosigmoid
ratio to be determined.
in particular cases there may be evidence of fetal colonic dilatation.
Short narrowed segment indicated between the yellow dotted lines; TZ = transition zone.
Yellow arrows indicate the small bowel (jejunal) pattern to the descending colon.
dilatation of the small
bowel (arrow) proximal to
transition zone. The large
bowel is shortened with
peculiar contours. There is
marked regurgitation of
barium into the dilated
Sigmoid volvulus is a cause of large bowel obstruction and occurs
when the sigmoid colon twists on the sigmoid mesocolon.
Sigmoid Volvulus. Dilated loop of sigmoid colon has a "coffee-bean" shape and the wall
between the two volvulated loops of sigmoid (black arrow) "points" towards the right upper
quadrant. There is a considerable amount of stool in the colon from chronic constipation.
Sigmoid volvulus with abdominal pain. (a) Plain abdominal radiography shows an air-filled, dilated
sigmoid colon (*) arising from the pelvis. Note a percutaneous endoscopic gastrostomy tube. (b) Coronal
reformatted contrast-enhanced CT image shows dilated sigmoid colon (*) with the beak sign (arrow).
Classic "bird of prey" appearance of Sigmoid
Volvulus on Barium study (arrow)Sigmoid Volvulus on plain film
Cecal volvulus with abdominal distention. (a) Abdominal radiograph shows air-distended cecum
in the coffee-bean shape (*) in the left abdomen. (b) Axial contrast-enhanced CT shows dilated
cecum (*) in the left abdomen and the whirl sign (arrows). c) Coronal reformatted contrast-
enhanced CT shows dilated cecum (*) with beak-like tapering (arrow) in the left abdomen.
Abdominal X-ray of Crohn's disease patient showing transmural
colonic inflammation (arrows) and ileal abnormalities
Ulcerative colitis is an inflammatory bowel disease that not only
predominantly affects the colon, but also has extraintestinal
Double contrast barium enema allows for exquisite detail of the colonic
mucosa and also allows the bowel proximal to strictures to be assessed.
Mucosal inflammation leads a granular appearance to the surface of the
bowel. As inflammation increases, the bowel wall and haustra thicken.
Mucosal ulcers are undermined (button-shaped ulcers). When most of the
mucosa has been lost, islands of mucosa remain giving it a pseudopolyp
In chronic cases, the bowel becomes featureless with the loss of normal
haustral markings, luminal narrowing and bowel shortening (lead pipe
Small islands of residual mucosa can grow into thin worm-like structures
(so-called filiform polyps)
Colorectal carcinoma in the setting of ulcerative colitis is more frequently
sessile and may appear to be a simple stricture.
CT showing inflammation and bowel wall thickening in ulcerative colitis
CT showing diffuse inflammation in Amebic Colitis.
Pseudomembranous colitis. (Left) Axial CT scan of the mid abdomen utilizing oral but not
intravenous contrast demonstrates marked thickening of the colonic wall (white arrows)
producing the so-called "accordion sign." There is a small amount of pericolonic stranding
(red arrow) and ascites (green arrow). (Right) Axial CT scan through the pelvis shows
marked thickening of the wall of the rectum (yellow arrows) indicating this is a pan-colitis
Colorectal carcinoma (CRC) is the most common cancer of the gastrointestinal tract and
the second most frequently diagnosed malignancy in adults. CT and MRI are the modalities
most frequently used for staging.
sensitivities for polyps >1 cm
single contrast: 77-94%
double contrast: 82-98%
polyps <1 cm: < 50% detection
Appearances will reflect macroscopic appearance, with lesions seen as filling defects. These
need to be differentiated from residual fecal matter. Typically they appear as exophytic or
sessile masses, or may be circumferential (apple core sign). Fistulas to bladder, vagina or
bowel may also be demonstrated.
Rarely the stenotic segment will be long particularly with scirrhous adenocarcinomas.
CT: CT is the modality most used for staging colorectal carcinoma, with an accuracy of only
between 45-77%, able to asses nodes and metastases.
It is often able to diagnose tumours although it is insensitive to small masses. CT colonography
is increasing in popularity as an alternative to colonoscopy.
Most colorectal carcinomas are of soft tissue density that narrow the bowel lumen. Ulceration in
larger mass is also seen. Occasionally low-density masses with low-density lymph nodes are seen
in mucinous adenocarcinoma, due to the majority of the tumour composed of extracellular
mucin. Psammomatous calcifications in mucinous adenocarcinoma can also be present.
Complications may also be evident, e.g. fistulae, obstruction, intussusception, perforation.
MRI: Has a staging accuracy of 73% with a 40% sensitivity for lymph node metastases.
MR is having an increasing role to play in the staging of rectal cancer.
Apple core lesion in ascending colon (arrow)
Mucinous Colon Cancer on CT (arrow)