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Introduction to Radiologic Imaging of the GI System effacement

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Introduction to Radiologic Imaging of the GI System effacement Powered By Docstoc
					                                                                                                        GI 2 #6
                                                                                  Tue Feb. 24, 2004, 10-11 a.m.
                                                                                       Dr. Pat G. Sharratt, D.O.
                                                                                                       Malik Ali
                                                                                                    Page 1 of 6
                  Introduction to Radiologic Imaging of the GI System
Note: This scribe is basically the same as found in pages 40 -47 of our syllabus and it follows along w/
the 32 images posted online by Dr. Sharratt. Also, Dr. Sharratt was gracious enough and went over t he
test material in the first 5 mins. of class which I have bolded in this scribe. He said that these items were
verbatim test questions from him.
        ABDOMEN: Esophagus, Stomach, Small Bowel, and Colon
I. - ESOPHAGUS
Reflux esophagitis: (Slide #1) Double-contrast esophagram in a patient with a sliding hiatal hernia
demonstrates effacement of linear folds and shallow ulcerations typical of reflux esophagitis.

Barrett's e sophagus and hiatal hernia: (Slide #2) This middle-aged man had a long history of
dyspepsia and heart burn. Spot film of the esophagus from a double-c ontrast upper GI series shows a
sliding hiatal hernia. Not e the "filigree" pattern -- fine reticular collections of barium between slightly
elevated mucosal folds in the distal esophagus, resembling the areae gastricae.

Example of a Barrett's esophagus. COMMENT: Barrett's esophagus is generally considered an
acquired disorder. Radiograph reflects the pres ence of columnar acid secreting gastric mucosa, now
present within the distal esophagus. Stricture formation may be a common s equela. You’ll see cases
of squamous cell carcinoma being most common → mid-esophagus. This may also
undergo adenocarcinomatous degeneration – distal 1/3 of esophagus – which is
associated w/ Barrett’s esophagus. Barrett’s esophagus is associated w/ gastro-
esophageal reflux.
Sliding hiatal hernia with Schatzki's ring: (Slide #3) This spot film shows small hiatus hernia. Numerous
gastric mucosal folds extend through the hiatus and to the prolapsed stomach. The esophagogastric
junction is marked by a well -defined symmetrical ring that measures 2 to 3 millimeters in height (Schatzki
ring). A Schatzki ring is seen in significant percentage of patients with hiatus hernia. It marks the
squamoc olumnar junction and therefore indicates the position of the esophagogastric junction.

Achalasia is another of the motility disorde rs. In t his instance, there is a failure of relax ation of the cardia
resulting in retention of food, saliva, and secretions in the esophagus.

(Slide #4) This 49-year-old man complained of progressive dysphagia for approximately two years. On
the left, an erect delay ed film of an esophagram shows a large dilated esophagus. Retained secretions
are layered above the barium. There is a small amount of barium within the stomach. The film on the
right reveals the esophagogastric junction to be a long narrowed segment with an intact mucosa. This
appearance is characteristic of achalasia.

Esophageal varices: The serpiginous filling defects in the distal third of the esophagus represent
esophageal varices. They changed slightly in c ontour and size during t he fluoroscopic examination.
(Slide #5 ) Bleed lik e crazy.

Esophageal infections are unusual. When they do occur, they are usually a result of opportunistic
invaders such as Candida, herpes simplex virus, or Cytomegalovirus. They almost always occur in
debilitated or immunosuppressed patients. (Slide #6) These three images are examples of Candida
esophagitis in three different patients with AIDS. The upper left -hand corner is a double-cont rast
esophagram revealing a coarse mucosa with shallow ulcerations. The upper right -hand c orner
radiograph shows replacement of the normal mucosal pattern of c oarse thickened mucosa. The lower
left-hand radiograph is a spot film of the mid esophagus in a third patient showing an elongated deep
ulcer. The findings were confirmed at endoscopy in all three patients.
                                                                                                  GI 2 #6
                                                                          Tue Feb. 24, 2004, 10-11 a.m.
                                                                                Dr. Pat G. Sharratt, D.O.
                                                                                                 Malik Ali
                                                                                              Page 2 of 6
COMME NT: The radiologic findings in Candida esophagitis vary with the degree of invasiveness. The
earliest radiologic manifestation is a fine mucosal irregularity which can be appreciated on double -
contrast studies. Unfortunately, many patients have s evere odynophagia and they may not be able to
tolerate a double-contrast ex amination. In patients with more extensive mucosal colonization, superficial
plaques and nodules may be seen radiographically. Spasm is frequently identified. Focal ulceration and
intraluminal masses may be seen in a small percent age of cases. Strictures may develop with healing.
These strictures may mimic the radiographic appearance of strictures that develop following inges tion of
corrosives.

Herpetic and Cytomegalovirus infections usually result in ulcerations of the esophageal mucosa. Herpetic
ulcerations are small well defined and aphthoid in appearance. Cytomegalovirus ulcers may be large and
extend over several centimeters.

This and the following are repres entative examples of carcinoma of the es ophagus. On this slide (Slide
#7) this elderly patient complained of progressive dysphagia and epigastric pain. The esophagram on the
left demonstrates an eccentric narrowing of the distal esophagus with an overhanging edge at the
proximal margin of the narrowed segment. The CT scan on the right demonstrates a filling defect in the
cardia which represents a large gastric metastasis.

This 70-year-old woman (slide #8) complained of progressive dysphagia for solid foods and a thirty -pound
weight loss over a three-week period. The esophagram on the left demonstrates a narrowed segment of
the mid and distal esophagus with mucosal destruction. Note the overhanging edges at the proximal
margin of the lesion. The CT examination on your right was obtained at the level of the carina. This
reveals tumors surrounding the markedly narrowed esophageal lumen which contains a small amount of
air and contrast material. Note compression of the carina and left main stem bronchus. No fat plane is
seen bet ween the mass and the aorta. Endoscopic biopsy reveals squamous cell carcinoma.

COMME NT: Most esophageal carcinomas appear in the middle t hird of the esophagus. The distal third,
particularly the region of the gastroesophageal junction, is the next most common site, while the proximal
esophagus is the least common site of this tumor. The differential diagnosis of esophageal carcinoma
includes achalasia, benign stricture, and Crohn's disease.
Not all filling defects of the esophagus are so ominous.

This young man (slide #9) complained of dysphagia for solids. As a child, he had undergone several
esophageal dilatations for a corrosive stricture. These two slides reveal a 2 -centimet er intraluminal filling
defect at the junction of the middle and distal thirds of the es ophagus. There is a narrowing of the distal
third of the esophagus with evidence of partial obstruction (note the fluid level). Further history revealed
that the patient was a drug dealer who concealed his drugs in a balloon that he swallowed when police
approached and regurgitated when they left.
II. - STOMACH
Developmental abnormalities encountered in the adult are not common to begin with. The two that occur
with any frequency, are gastric duplications and prepyloric antral webs.
Gastric duplication: (slide #10) These two radiographs, supine and erect views of a double contrast study,
show a large sharply demarcated submucosal mass projecting into t he gastric l umen. Not e the
effacement of the overlying mucos a. Operation revealed a duplication cyst.
Prepyloric antral web: (slide #11) This 63-year-old man complained of episodic, epigastric distress and
intermittent vomiting. The uppermost image is from a double contrast spot film; the lower is from a single-
contrast spot film. Note a band-like linear defect with a 1-centimeter central aperture in the antral portion
of the stomach. The location, about 1.5 centimeters proximal to the pyloric channel, is typica l of both
congenital (usually) and acquired antral webs → most acquired through scarring from PUD.

COMME NT: Prepyloric antral webs (also known as diaphragms or membranes) are encountered mainly
in two age groups: young infants and the middle -aged (fifth and sixth decades). A ntral webs found in
infants are presumably of development al origin; while congenital webs undoubtedly occur in adults, the
                                                                                               GI 2 #6
                                                                        Tue Feb. 24, 2004, 10-11 a.m.
                                                                              Dr. Pat G. Sharratt, D.O.
                                                                                              Malik Ali
                                                                                           Page 3 of 6
great majority of duodenal webs detected after childhood are probably related to peptic ulcer disease.
Gastric outlet obstruction may occur in chronic or untreated cases.

The typical radiologic features of a benign gastric ulcer include the following: 1)
projection of the barium -filled crat er beyond the gastric lumen, 2) mucosal folds radiated to the
margin of the ulcer, 3) a fine 1 - 2 mm collar at t he neck of the ulcer (Hampton's line). Spasm is a
common associated finding.

(Slide #12) These two images exemplify a benign gastric ulcer. The one on the left reveals the ulcer in
profile. The ulcer has a long neck and a surrounding inflammatory mound. On the right is an en face
view revealing effacement of the rugal folds in the vicinity of the crater. The diagnosis of benign gastric
ulcer was confirmed by endoscopy. Ulcers have to be Bx to tell if benign or malignant.

Gastric neoplasms may be benign or malignant.

Benign gastric tumors may be classified into two broad morphologic groups: 1) mucosal (polypoid), 2)
submucosal.

Mucosal benign neoplasm: Most common of the benign gastric neoplasms is the benign gastric polyp
occurring in 1 - 2% of the adult population. These are best demonstrated by the double -cont rast
technique. Approximat ely 50% of the patients with gastric polyps have more than one. (Slide #13) As
can be seen on this study, this 66 -year-old woman had multiple polyps. The arrows point to prolapse of
one of these poly ps through an anastomotic junction bet ween the stomach remnant and the jejunum.
This is evidence of the patient's prior history of a Billrot h II type of gastrectomy. A Billrot h II gastrectomy
is an antrectomy with an antec olic end t o side gastrojejunostomy. (A Billrot h I gastrectomy is commonly
used in North America to describe a partial gastrectomy (Antrectomy) with gastroduodenostomy. The
procedure may be end to end or end to side or side to side with a superior, inferior, posterior, or anterior
anastamosis.

Submucosal: S ubmucosal lesions may be leiomy omas, lipomas, neurofibromas, carcinoid, hemangioma,
myoblastoma, and hemangiopericytoma. (Slide #14) The study above reveals a prolapsing antral lipoma.
This 53-year-old woman had an upper GI series as part of a staging work -up for carcinoma of the cervix.
She had no gastrointestinal complaints. The four slides above are sequential spot films s howing an oval
4 cm mass extending from t he antrum into the duodenum. The mass has a smoot h sharply defined
border and exhibits changeability from film to film. The CT scan below s hows a well - defined int raluminal
filling defect in the antroduodenal region. (Slide #15) The CT number was -57 hu., consistent with fat
(lipoma).

Malignant neoplasm s of the stomach are the 7th leading cause of cancer deaths in the Unit ed States.
There is an incidence of approximately 8 per 100,000. Gastric carcinomas generally arise in
the distal portion of an otherwise normal stomach. Gastric carcinoma typically
metastasizes to the liver and to regional lymph nodes. Scirrhous carcinoma may spread s ubmucosally
extending to the pylorus or esophagus.
This is representative of the superficial spreading type of gastric cancer. (Slide #16) This 68-year-old
man present ed with dysphagia. Both spot films of the Upper GI series show grossly thickened antral
folds. Note t he changeable contour of the affected segment. There was no delay in gastri c emptying. A
partial gastrectomy was performed. Pathological examination revealed a moderately differentiated
adenocarcinoma involving the mucosa and submucosa. Tumor was present in the lymphatics and
regional lymph nodes (bad news ).

(Slide #17) This middle-aged man presented with dyspepsia and weight loss. A prone oblique view of the
stomach shows a 6-centimeter fixed polypoid lesion on the greater curvat ure of t he stomach. The CT
examinations shown to the right are adjacent slices and show bot h t he mural (arrows in the more superior
image) and intraluminal (arrows in the lower CT scan) components of the neoplasm.
                                                                                                     GI 2 #6
                                                                               Tue Feb. 24, 2004, 10-11 a.m.
                                                                                    Dr. Pat G. Sharratt, D.O.
                                                                                                    Malik Ali
                                                                                                 Page 4 of 6
III. - DUODENUM - inch for inch, one of the most common
Peptic ulceration of the duodenum represents a wide range of radiologic appearances. A small duodenal
ulcer may have the appearance of an ulcer crater as seen above. (Slide #18) This is a supine film from
an upper GI series revealing a half-centimeter collection of barium within a cent rally located posterior wall
ulcer. The duodenal bulb is not deformed.

The failure to demonstrate an ulcer crater does not exclude active disease in patients with a typical clover
leaf deformity as seen above. This is a common finding in patients with severe peptic ulceration in which
there is scarring and spasm of the duodenal cap.         COMME NT: Time constraints preclude further
discussion of bot h benign and malignant pathology that may be found in this short segment of small
bowel known as the duodenum. Suffice it to say that inch for inch the du odenum is one of the most
common sites of malignancy in the gastrointestinal tract. While primary carcinoma may develop
anywhere along the cours e of the duodenal sweep, the region of the ampulla of Vater is the most
common site (b/c the gall bladder empties there also), and the duodenal bulb the least common site.
IV. - SMALL BOWEL
The small bowel may be associated with malabsorption syndromes, parasitic infestations, enteric
infections, and may be affected by neoplasms (benign and malignant), metastatic and primary. A number
of disorders are associated with the radiologic "malabsorption" pattern. The most common are sprue
"gluten-induced enteropathy" and lymphoma. Less frequent causes include radiation enteritis, Whipple's
disease, eosinophilic syndrome with small bowel involvement, eosinophilic gastroenteritis, ischemia,
mastocytosis, and pancreatic exocrine deficiency.

Barium studies classically show moderat e dilat ation of t he entire small bowel (2-4 cm norm). The
valvulae conniventes (2-4 mm norm) are generally prominent. And there may be reversal of the normal
ratio of jejunal and ileal folds -- the so-called "flip-flop" pattern -- characteristic of sprue, as can be seen
on this slide (you should have jejunal > ileal folds). The number of folds per inch is decreas ed in the
jejunum and increased in the ileum, i.e., the reverse of the normal small bowel fold count. Unfortunately,
the abnormal findings of the small bowel are very non-specific.

(Slide #19) A small bowel series in this 64-year-old woman reveals prominence of the valvulae
connivent es in a dilated small bowel. She had present ed with steatorrhea, weight loss, and arthritis. The
scattered 2 - 3 millimet er filling defects in the proximal jejunum represent mucosal nodules characteristic
of this disease.

In this day of A IDS, cryptosporidiosis should not be forgotten. (Slide #20) This 31-year-old intravenous
drug abuser complained of relentless diarrhea and severe weight loss. A small bowel series showed
dilution of the barium by excessive secretions. There is marked thickening of t he mucosal folds of the
duodenum and the valvulae conniventes of the small bowel due to edema. Note the tubular characterless
appearance of the distal small bowel.

No discussion of the small bowel can be complete without mentioning Crohn's diseas e (ak a terminal
ileaitis). Crohn's disease may involve any portion of the digestive tract including
the oral pharynx, esophagus, and stomach. Can occur mouth to anus; anywhere
in the GI tract; any part or all of the GI tract. Skeletal manifestations are not unc ommon.
Crohn's colitis is pictured here with t his skip lesion. (Slide #21) This is the barium enema performed on a
26-year-old woman with diarrhea and weight loss. It shows segmental narrowing of the desc ending colon
and proximal sigmoid colon. The mucosa is markedly irregular and nodular. Note the aphthous
ulcerations and pseudo polyps on the detail view. The slide on your right reveals a second area of
involvement in the mid trans verse colon. Here manifestations include narrowing, loss of haustrations in a
granular mucosa. The remainder of the colon looks normal including the rectum.

(Slide #22) This is typical ileoc ecal involvement in Crohn's diseas e. This 45-year-old woman had a long
history of "mucosy" diarrhea and weight loss. A spot film of a small bowel series shows a fixed "C" loop
                                                                                                   GI 2 #6
                                                                             Tue Feb. 24, 2004, 10-11 a.m.
                                                                                  Dr. Pat G. Sharratt, D.O.
                                                                                                  Malik Ali
                                                                                               Page 5 of 6
of the terminal ileum with sacculations, narrowing, and several tight strictures. The configuration of the
infected loop indicates the presence of an inflammatory mass in the adjacent mesentery. The cecum has
a conical configuration due to entrance involvement by Crohn's disease. Note the mass effect on the
cecum and the terminal ileum caus ed by an inflammatory mass in the adjacent mesentery.

Finally as our population has aged and lived longer, and as the young adult population has found more
and more things to inject into their bodies, small bowel ischemia has increasingly become a topic for
discussion. (Slide #23) The slide shown above is of a 25-year-old woman with long-standing lupus
erythematosus who presented to the Emergency Room with severe and ac ute abdominal pain. The
barium enema with reflux into the terminal ileum shows marked thumb -printing and a "stacked-coin"
appearance with separation of adjacent loops. A CT of the pelvis (middle figure) s hows a narrowed loop
of ileum marked with thickening of its wall (arrow 1). The normal ut erus is seen below the ileum (arrow 2).
The CT scan on your right is a higher cut showing the thickening of the smal l bowel mesentery.

Small bowel ischemia is most commonly associated with congestive heart failure, cardiogenic shock,
lupus erythematosus, mesenteric venous thrombosis, and atherosclerosis of both small and large
vessels. Associated radiographic findings may be pneumatosis intestinalis and or portal venous air.
V. - COLON
Although other imaging modalities such as ultrasound, computed tomography, magnetic resonance, and
angiography are used to evaluate the colon, the barium enema remains the basic method of radiologic
assessment. Whether to employ the single or double contrast technique has been the subject of spirited
debate over the past two decades. Double -cont rast barium enema is preferred by sub-specialists and
has become the more frequent type of colon examination at most hospitals

Colonoscopy c omplements radiographic examination of the c olon and may resolve questions
unanswered by the latter. Colonoscopy has important limitations: It sometimes fails to evaluate the right
colon; it does not give a general overview of the colon; it generally does not provide permanent visual
record; and it is substantially more expensive (in the United States) then either the single-contrast or
double-contrast enema.

Diverticulosis and diverticulitis are frequent findings on barium enema of t he colon. (Slide #25) Here a
perforated sigmoid diverticulum is observed in a 65-y ear-old man presented with lower abdominal pain of
acute onset wit h this and had associated fever and vomiting. B arium enema shows scattered sigmoid
diverticulum with free spill of barium into the peritoneal cavity. The leakage of barium from the apex of
the large diverticulum is seen in the slide on your right.

Appendiceal abscess with an appendicoliths: (Slide #26) This teenage girl with spina bifida and
ventriculoperitoneal shunt had right lower quadrant pain and fever for several days. Physical examination
revealed a tender right lower quadrant mass. The more s uperior image A reveals a fold soft tissue mass
measuring approximately 8 centimet ers by 6 centimeters in t he right lower quadrant of t he abdomen.
Within this region t wo oval laminat ed calcifications typical of appendicoliths may be observed. On the two
CT images, B and C, the more superior is obtained at the level of the ascendi ng c olon and reveals a gas
containing soft tissue mass displacing the cecum (arrow 1) medially. A loop of ileum (arrow 2) is draped
over t he mass. On a more caudal cut, the more inferior CT examination, the appendicolit hs are seen
within the mass, which lies lateral to the cecum (arrow). The appendix itself cannot be identified.
A positive CT Scan rules in an appendicitis, but a negative CT Scan does not rule it out. A positive CT
confirms it only if you have: a symptomatic pt., rock s in the appendix, and an inflammatory mass in the
appendiceal area.

Ulcerative colitis is a proctocolitis that extends approximately to a variable extent; in its severest form, the
entire colon is affected. The incidence is in the third and fourth decades; however, the disease may
appear as late as the sixth decade.
                                                                                                        GI 2 #6
                                                                                Tue Feb. 24, 2004, 10-11 a.m.
                                                                                      Dr. Pat G. Sharratt, D.O.
                                                                                                       Malik Ali
                                                                                                    Page 6 of 6
The earliest radiologic manifestation of ulcerative colitis is the granularity of the rectal and colic mucosa,
which may be best seen on a double-cont rast barium enema examination.

This is an acute ulcerative colitis on the left and progression on the right. This 14-year-old boy had
several month history of bloody diarrhea. Barium enema on the left shows pan -colitis with extensive
ulceration of the sigmoid colon. The ulcers are symmetrical and of the c ollar-button type. The slide on
the right shows 5 years later. A double-contrast barium enema shows a narrowed ahaustral sigmoid and
descending colon. The affected segments have a granular mucosa. Ulceration is no longer evident.

There are a tremendous number of infectious colitis etiologies. In my opinion, one of the most important is
atrogenically induced infectious colitis caused by clostridium diphicele. It is almost always secondary to
antibiotic therapy with linc omycin being the primary offender. This is a 29-year-old man who developed
explosive non-bloody diarrhea several days after undergoing t ransplantation. On this barium enema,
note the extensive edema of the entire colon with the prominent mucosal ridges. Although the mucosal
contour is shaggy and irregular, there is no evidence of ulceration. The descending and trans verse c olon
are spastic and ahaustral. Sigmoidoscopy revealed extensive pseudomembrane formation. The patient’s
condition improved dramatically after cessation of antibiotic therapy (iatrogenically induced).

Not so new but interesting things are seen more frequently on barium enema examination, and I include
these only as aside in view of the prevalence of sexually transmitted diseases including AIDS. This first
slide is condolyma acuminata with associated carcinoma of the rectum. This is a 40-y ear-old homosexual
man who has the typical verrucus warts on the perineum and a bloody rectal discharge. Barium enema
showed a smooth dome-like mass arising at the anal verge and extending intraluminally. Also note the
irregular crescentic deformity of the rectal wall (arrows). At proctoscopy, the latter proved to be an
ulcerating carcinoma. Although malignant degeneration of condyloma is a recognized complication, t he
two lesions were unrelat ed in this patient.

Gonococcal proctitis: This 28-year-old homosexual man complained of tenesmus and rectal discharge.
Front al and lateral views of barium enema show severe spasm and ulceration of the rectum.
Gonococcus was cultured from rectal secretions.

This is an example of malignant degeneration in an edematous polyp. This 70-year-old man presented
with rectal bleeding. On the left single and on the right, double-contrast films from a barium enema show
multilobular sessile mass in the sigmoid colon. The lesion measures 3 x 2 x 2 centimeters. Note t he 1 -
centimeter area of puckering at its attachment to the bowel wall, a finding that strongly suggests
neoplastic invasion. Endoscopy revealed an adenocarcinoma arising in an adenomatous polyp.

                                  Ischemia of the colon is usually secondary to
The large bowel is also subject to ischemia.
atherosclerosis of the mesentery circulation (small or large vessels); less often it is
due to vasculitis such as lupus erythemat osus, a low flow state following surgery, hemorrhagic shock,
veno-occlusive disease, venous thrombosis or rarely Burger's. Patient typically presents with acute
abdominal pain and diarrhea, passing mucus and small amounts of blood by the rectum. Some persons
have little or no pain. This is a 32-year-old woman who developed acute abdominal pain and bloody
diarrhea while receiving chemotherapy for choriocarcinoma. A barium enema shows extensive thumb -
printing of the trans verse colon and proximal descending colon. There is marked spasm of the involved
bowel segments. Thes e changes whic h are most likely secondary to mesentery venous thrombosis
resolved completely after several days.

Blood supply to colon: superior and inferior mesenteric arteries. Superior gives
rise to the right and middle colic arteries whereas the inferior gives rise to the left
colic artery.

				
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Description: Introduction to Radiologic Imaging of the GI System effacement