Chapter 31 - Colon and Appendix (CHERI NOTES) Flashcards
1
Q
TRUE OR FALSE.SINGLE CONTRAST BARIUM ENEMA is still occasionally used for the evaluation of colonic obstruction; fistulas and in old; seriously ill or debilitated patients. (p. 780)
A
TRUE
2
Q
TRUE OR FALSE.
DOUBLE-CONTRAST (air contrast) barium enema is favored for detection of small lesions (< 1 cm); for documentation of
inflammatory bowel disease and for detailed imaging evaluation of the rectum. (p.780)”
A
TRUE
3
Q
___ complements colonoscopy and barium examinations
by demonstrating intramural and extracolonic components of
disease. (p.780)
- it is excellent for demonstrating extrinsic inflammatory
and neoplastic processes that affect the colon:
abscesses; sinuses and fistulas.
A
CT
- Colonoscopy is sporadically limited by occasional failure
to reach the right colon - then; barium enema or virtual colonoscopy is utilized to
complete the examination.
4
Q
_____ is more accurate than CT or MR in determining local tumor
extent of rectal carcinomas and is used in the evaluation of other
rectal and perirectal diseases. (p.780)
A
TRANSRECTAL ULTRASOUND
5
Q
_____ refers to a radiolucency in a barium pool caused by a
protruding mass lesion. (p.781)
A
FILLING DEFECT
- on barium enema examinations; filling defects may be POLYPS;
TUMORS; PLAQUES; AIR BUBBLES; FECES; MUCUS or FOREIGN
OBJECTS.
6
Q
____ are protrusions from the mucosa that produce filling defects
in defects in pools of barium or are etched in white when coated
by barium and outlined by air on double-contrast studies. (p.781)
A
POLYPS
- may be pedunculated on a stalk or sessile
- they may appearr as “BOWLER HATS” when viewed obliquely
- the term “polyp” is a generic for a protruding lesion and does
not imply a histologic diagnosis.
7
Q
Air bubbles rise to the highest point of a contrast column
(the “_____ sign”); but fecal material usually remains
dependent. (p.781-782)
A
CARPENTER’S LEVEL SIGN
- Plaques are flat lesions that barely rise above the mucosal
surface.
8
Q
_____ is the most common malignancy of the GI tract and the
second most common malignancy in the U.S. (p.782)
A
COLORECTAL ADENOCARCINOMA
9
Q
Approximately 50% of Colorectal CA arise in the
___ and __ area. (p.782)
A
RECTUM and RECTOSIGMOID AREA
- another 25% occur in the sigmoid colon; and
the remaining 25% are evenly distributed
throughout the remainder of the colon. - nearly all cancers of the colon are
adenocarcinomas arising from preexisting
adenomas - most tumors are annular constricting lesions;
2 to 6 cm in diameter; with raised everted edges
and ulcerated mucosa.
10
Q
TRUE OR FALSE.
Polypoid tumors are less common; some having the
frond-like appearance of villous carcinoma. (p.782)
A
TRUE
- INFILTRATING SCIRRHOUS TUMORS; so common in gastric CA;
are rare in the large intestine; unless the patient has ulcerative
colitis. (p.782) - the tumor spreads by direct invasion through the bowel wall
into pericolonic fat and adjacent organs; lymphatic channels to
regional nodes and hematogeneously through the portal veins
to the liver and systemic circulation.
11
Q
TRUE OR FALSE.
In colorectal adenoCA; INTRAPERITONEAL SEEDING from a tumor
that penetrates the colon wall may also occur. (p.782)
A
TRUE
12
Q
__ is the most frequent complication of colorectal adenoCA (p.782)
A
OBSTRUCTION
- other complications are uncommon but include perforation;
instussusception; abscess and fistula formation. - up to 20% of patients have a second tumor of the large bowel
at diagnosis; usually an adenoma or another carcinoma. - approximately 5% of patients will have a second colorectal
CA either simultaneously or subsequently diagnosed.
13
Q
TRUE OR FALSE.
Patients with ulcerative colitis; Crohn Disease; Familial
adenomatous polyposis syndrome and Peutz-Jeghers syndrome
are at increased risk of colon carcinoma. (p.783)
A
TRUE
14
Q
Local disease staging of Colorectal AdenoCA is best evaluated
with ____ or ______. (p.783)
A
TRANSRECTAL or COLONOSCOPIC
ULTRASOUND
- CT and MR are used for more advanced
disease and to detect recurrence. - microscopic invasion through the bowel wall
andd tumor involvement of normal sized lymph
nodes is not detected by CT or MR.
15
Q
DIAGNOSIS? (colon) (p.783)
Cross-sectional imaging findings include:
1. Polypoid primary tumor (usually >1 cm)
2. “Apple-core lesions” with bulky; irregular thickening of the
colon wall and irregular narrowing of the lumen.
3. Cystic; necrotic and hemorrhagic areas within the tumor mass;
esp. when the tumor is large.
4. Linear soft tissue stranding into the pericolonic fat often
indicative of tumor extension through the bowel wall
5. Enlarged regional lymph nodes (>1 cm) representing
lymphatic spread of tumor
6. Distant metastases; esp. in the liver.
A
COLORECTAL ADENOCARCINOMA
- When tumor cause colonic
obstruction;edema or ischemia may thicken
the wall of the uninvolved colon
proximal to the tumor.
16
Q
4 most common sites of tumor reccurences in COLORECTAL
ADENOCARCINOMA? (p.783)
A
1. AT THE OPERATIVE SITE; near the bowel anastomosis 2. IN LYMPH NODES that drain the operative site 3. IN THE PERITONEAL CAVITY 4. IN THE LIVER AND DISTANT ORGANS
- The entire abdominal cavity must
be surveyed to detect tumor recurrence - CT; MR and PET-CT are utilized to demonstrate
response to therapy and tumor recurrence
17
Q
A ____ is defined as a localized mass that projects from the
mucosa into the lumen. (p.783)
A
POLYP
- because the majority of colorectal cancers are believed to arise from pre-existing adenomatous polyps; the detection of polyps is a major indication for colonosocpy and imaging studies of the colon.
18
Q
TRUE OR FALSE.
- Polyps less than 5 mm are almost all hyperplastic;
with a risk of malignancy less than 0.5%.
- Polyps 5 to 10 mm in size are 90% adenomas;
with a risk of malignancy of 1% - Polyps 10 to 20 mm in size are 90% adenomas;
with a risk of malignancy of 10% - Polyps larger than 20 mm are 50% malignant
A
TRUE
19
Q
_____ polyps are nonneoplastic mucosal proliferation.
They are round and sessile. Nearly all are less than 5 mm in size.
(p.783)
A
HYPERPLASTIC POLYPS
20
Q
_____ polyps are distinctly premalignant and a major risk for
development of colorectal carcinoma. (p.783)
A
ADENOMATOUS POLYPS
- these are neoplasms with a core of connective tissue - approximately 5% to 10% of population older than 40 years have adenomatous polyps
21
Q
\_\_\_\_\_\_\_ polyps (\_\_\_\_\_\_ polyps) represent 1% of colon polyps. They are a common cause of rectal bleeding in CHILDREN. (p.783)
A
HAMARTOMATOUS POLYPS
(JUVENILE POLYPS)
- The Peutz-Jeghers polyp is a
type of hamartomatous polyp.
22
Q
_____ polyps are usually multiple and associated with inflammatory
bowel disease. They account for less than 0.5% of colorectal polyps.
(p.783)
A
INFLAMMATORY POLYPS
23
Q
TRUE OR FALSE.
FAMILIAL ADENOMATOUS POLYPOSIS SYNDROME is approx.
two-thirds inherited and one-third spontaneous. (p.784)
- Polyps typically carpet the entire colon.
A
TRUE
- the inheritance pattern is AUTOSOMAL DOMINANT with high penetrance - the polyps are tubulovillous adenomas; which usually are evident by age 20. - Colorectal cancer will eventually develop in nearly all patients; and so; total colectomy with rectal mucosectomy and ileoanal pouch construction is the current recommended therapy.
24
Q
TRUE OR FALSE.
In FAMILIAL ADENOMATOUS POLYPOSIS SYNDROME
- patients are at risk for numerous extracolonic
manifestation including carcinomas of the small
bowel; thyroid carcinoma; and mesenteric
fibromatosis. (p.784)
A
TRUE
25
FAMILIAL ADENOMATOUS POLYPOSIS SYNDROME patients with
associated bone and skin abnormalities including cortical
thickening of the ribs and long bones; osteomas of the skull;
supernumerary teeth; exostoses of the mandible; and dermal
fibromas; desmoids; and epidermal inclusion cysts have
been diagnosed as _____ syndrome. (p.784)
GARDNER SYNDROME
26
FAMILIAL ADENOMATOUS POLYPOSIS SYNDROME patients with
associated tumors of the CNS have been grouped as
_____ syndrome. (p.784)
TURCOT SYNDROME
27
_____ polyps are nonneoplastic growths with a smooth muscle core
covered by mature glandular epithelium. (p.784)
HAMARTOMATOUS POLYPS
- however; patients with the hamartomatous
polyposis syndromes may also
develop adenomatous polyps;
which do carry a risk of malignancy.
28
TRUE OR FALSE.
PEUTZ-JEGHERS SYNDROME predominantly involves the SMALL BOWEL;
but most cases have gastric and colon polyps as well.
TRUE
```
- the condition is autosomal
dominant with incomplete
penetrance.
- dark pigmented spots on the
skin and the mucosal membranes
are characteristic.
- risk of carcinoma arising from
coexisting adenomatous polyps
is 2% to 20%
- patients are also at risk for
breast CA; uterine and ovarian CA
and early age cancer of the pancreas.
```
29
_____ is a syndrome of multiple hamartomas including
hamartomatous polyposis of the GI tract; WITH GOITER AND
THYROID ADENOMAS and increased risk of breast cancer
and transitional cell carcinoma of the urinary tract. (p.784)
COWDEN DISEASE
- The syndrome is autosomal dominant and affects mainly Caucasians
- all patients have mucocutaneous lesions with facial papules; oral papillomas and palmoplantar keratoses
30
_____ syndrome is a disease of OLDER PATIENTS with a
mean age of onset of 60 years. (p.784)
- polyps are distributed througout the stomach; small bowel; and colon.
CRONKHITE-CANADA SYNDROME
- associated skin findings include nail atrophy; brownish skin pigmentation and alopecia.
- patients present with watery diarrhea and protein-losing enteropathy.
31
TRUE OR FALSE.
LYMPHOID HYPERPLASIA may involve the colon. The normal
lymphoid follicular pattern of diffuse tiny nodules 1 to 3 mm in
diameter with characteristic umbilication is most common in the
TERMINAL ILEUM AND CECUM but may involve any portion of the
colon.
TRUE
```
- the nodular lymphoid
hyperplasia pattern of diffuse
nodules larger than 4 mm is associated
with allergic; infectious;
and inflammatory disorders.
```
32
TRUE OR FALSE.
Involvement of the cecum or rectum is most common with
anal and rectal lymphoma increasingly frequent in AIDS patients.
(p.784)
TRUE
```
- the colon is less commonly
involved with lymphoma than the
stomach or small bowel.
- most are non-hodgkin b-cell
lymphoma.
- morphologic patterns include
small to large nodules that may
ulcerate; excavate and perforate
and diffuse infiltration of the
bowel wall resulting in bulbous folds
and thickened bowel wall.
```
33
TRUE OR FALSE.
LYMPHOMA NODULES vary in size although LYMPHOID HYPERPLASIA
NODULES are uniform in size. (p.785)
TRUE
- the diffuse multinodular form may be
difficult to differentiate from nodular
lymphoid hyperplasia.
34
TRUE OR FALSE.
(In colonic lymphoma); as in the small intestine; marked
narrowing of the lumen is uncommon; aneurysmal
dilation occurs when transmural disease destroys innervation.
TRUE
35
____ account for nearly all mesenchymal tumors of the colon.
| p.785
GI stromal tumors (GISTs)
```
- true colonic leiomyomas and
leiomyosarcomas are very rare
- GISTs are much less common
in the colon than in the stomach
and small bowel accounting
for only 7% of the total.
- as in the remainder of the GI tract
they may appear as exophytic;
mural or intramural masses.
- ulceration is relatively frequent.
- hemorrhagic; cystic change; necrosis
and calcifications are more common
in larger tumors.
```
36
____ is the most common submucosal tumor of the colon. (p.785)
LIPOMA
```
- barium studies demonstrate a smooth;
well-defined elliptical filling defect;
usually 1 to 3 cm in diameter.
- the tumors are soft and change
shape with compression.
- CT demonstration of a fat density tumor
is definitive.
```
37
2 most frequent locations of the colonic lipomas. (p.785)
CECUM and ASCENDING COLON
- nearly 40% present with intussusception
38
TRUE OR FALSE.
EXTRINSIC MASSES commonly cause mass effect on the colon
that may simulate intrinsic disease. (p.785)
TRUE
39
TRUE OR FALSE.
ENDOMETRIOSIS commonly implants on the sigmoid colon and
the rectum. (p.785)
TRUE
- defects are frequently multiple
and of variable size.
- lesions are commonly within
the cul-de-sac
```
* barium studies demonstrate
sharply defined defects that
compress but do not usually
encircle the lumen.
* CT demonstrates complex
cystic pelvic masses with high-
density fluid components.
Multiple pelvic organs may be
incorporated into the mass.
* MR demonstrates masses with
signal characteristics of hemorrhage.
```
40
______ such as ovarian cysts ; cystadenomas; teratomas; and
uterine fibroids produce smooth extrinsic mass impressions of the
colonic wall. The colon is displaced but not invaded. (p.785)
BENIGN PELVIC MASSES
41
MALIGNANT PELVIC TUMORS and METASTASES may involve the
colon by these 3 ways. (p.785)
- the involved colon demonstrates thickening of the wall;
separation of folds; spiculation; angulations; narrowing and
serosal plaques.
```
1. BY CONTIGUOUS SPREAD;
spread along mesenteric fascial
planes
2. BY INTRAPERITONEAL SEEDING;
through lymphatic channels
3. BY EMBOLUS through blood
vessels.
```
- metastases oten cannot be
differentiated from primary
tumors by imaging methods
42
TRUE OR FALSE.
Crohn disease and metastatic disease may also look exactly
alike radiographically. (p.785)
TRUE
-CT or MR demonstrates contiguous involvement
of the colon and the rectum by pelvic tumors.
43
______ is an uncommon idiopathic inflammatory disease
| involving primarily the mucosa and submucosa of the colon.
ULCERATIVE COLITIS
- the peak for its appearance is 20 to 40 years;
but onset of disease after age 50 is common.
- the disease consists of superficial ulcerations;
edema and hyperemia.
44
4 Radiographic hallmarks of Ulcerative Colitis. (p.785-786)
1. Granular mucosa
2. Confluent shallow ulcerations
3. Symmetry of disease around
the lumen
4. Continuous confluent diffuse
involvement
```
- an early fine; granular pattern
is produced by mucosal hyperemia
and edema that precedes ulceration.
- superficial ulcers spread to cover
the entire mucosal surface
- the mucosa is stippled with barium
adhering to the superficial ulcers.
```
45
____ ulcers are deeper ulcerations of thickened edematous
| mucosa with crypt abscesses extending into the submucosa. (p.786)
COLLAR BUTTON ULCERS
```
- A coarse granular pattern is produced
later by the replacement of diffusely
ulcerated mucosa with granulation
tissue.
- late changes include a variety of
polypoid lesions.
```
46
____polyps are mucosal remnants in areas of extensive ulceration.
(p.786)
PSEUDOPOLYPS
47
____ polyps are small islands of inflamed mucosa. (p.786)
INFLAMMATORY POLYPS
48
____ polyps are mucosal tags that are seen in the quiescent
| phases of the disease (ulcerative colitis). (p.786)
POSTINFLAMMATORY POLYPS
49
___ polyps are postinflammatory polyps with a characteristic
| worm-like appearance. (p.786)
FILIFORM POLYPS
- typically seen in an otherwise
normal appearing colon
50
____ polyps may occur during healing after mucosal injury. (p.786)
- involvement typically extends from the rectum proximally in
a symmetric and continuous pattern. (p.786)
HYPERPLASTIC POLYPS
- the terminal ileum is nearly always
normal in ulcerative colitis
51
Rare ______ may produce an ulcerated but
| patulous terminal ileum. (p.786)
BACKWASH ILEITIS
52
```
DIAGNOSIS? (COLON) (p.786)
CT findings include:
1. wall thickening; often with "halo sign"
of low-density submucosal edema
2. Narrowing of the lumen of the colon
3. Pseudopolyps and pneumatosis coli
with megacolon.
```
ULCERATIVE COLITIS
53
4 complications of Ulcerative Colitis (p.786)
```
1. Strictures; usually 2 to 3 cm
or more in length and commonly
involving the transverse colon
and the rectum
2. Colorectal AdenoCA; with an
approximate risk of 1% per year of
disease
3. Toxic megacolon (2% to 5% of cases)
may be the initial manifestation
4. Massive hemorrhage
```
54
TRUE OR FALSE.
Associated extraintestinal diseases of Ulcerative Colitis include:
Sacroilitis mimicking ankylosing spondylitis (20% of cases); eye lesions
including uveitis and iritis (10% of cases); cholangitis and an increased
incidence of thromboembolic disease. (p.786)
TRUE
55
This disease condition involves the colon in 2/3rds of all cases and is
isolated to the colon in approximately 1/3 of all cases.
- its hallmarks include early aphthous ulcers; later confluent
deep ulcerations; predominant right colon disease; discontinuous
involvement with intervening regions of normal bowel;
assymetric involvement of the bowel wall; strictures; fistulas and
sinus formation. (p.786)
CROHN DISEASE
```
- pseudodiverticula of the colon are
formed by asymmetric fibrosis on
one side of the lumen; causing
saccular outpouches on the other
side.
- involvement of the rectum is
characterized by deep rectal ulcers
and multiple fistulous tracts to the skin.
```
56
TRUE OR FALSE.
```
INFECTIOUS COLITIS may be caused by various bacteria (Salmonella;
Shigella; and Escherichia coli); parasites; viruses (CMV and herpes);
and fungi (histoplasmosis and mucormycosis). (p.787)
```
TRUE
```
- most cause a pancolitis with
edema and inflammatory wall
thickening with infiltration of
pericolonic fat.
- pericolonic fluid and
intraperitoneal fluid may be
present
```
57
______ is a potentially fatal condition characterized by marked
colonic distension and risk of perforation. (p.787)
TOXIC MEGACOLON
```
- it occurs as a complication of fulminant
colitis often caused by ulcerative colitis;
Crohn disease; pseudomembranous
colitis; use of anti-diarrheal drugs and
hypokalemia.
- transmural inflammation causes large
areas of denuded mucosa; deep ulcers
that may extend to the serosa surface
and loss of muscle tone.
```
58
DIAGNOSIS? (COLON) (p.787)
Radiographic findings include:
1. Marked dilatation of the colon (transverse colon > 6 cm)
with absence of haustral markings
2. edema and thickening of the colon wall
3. pneumatosis coli
4. evidence of perforation
TOXIC MEGACOLON
59
TRUE OR FALSE.
Barium studies should be avoided in TOXIC MEGACOLON
avoided because of risk of perforation. (p.787)
TRUE
60
_____ is an inflammatory disease of the colon; and occasionally;
the small bowel; characterized by the presence of a
pseudomembrane of necrotic debris and overgrowth of Clostridium
difficile. (p.787)
PSEUDOMEMBRANOUS COLITIS
```
- there are many contributing causes
including antibiotics (any that change
bowel flora); intestinal ischemia
(especially following surgery); irradiation;
long-term steroids; shock and colonic
obstruction.
- the disease presents as fulminant
inflammatory bowel disease with
diarrhea and foul stools
```
61
```
DIAGNOSIS? (COLON) (p.788)
Conventional radiographs may reveal:
1. Dilated colon
2. Nodular thickening of the haustra
3. Ascites
```
TOXIC MEGACOLON
```
- BARIUM ENEMA demonstrates an
irregular lumen with thumbprint
indentations similar to ischemic
colitis.
- superficial ulcers are common
- plaque-like defects on the
mucosal surface are due to the
pseudomembranes
- the colitis is frequently patchy in distribution
with sparing of the rectum.
```
62
DIAGNOSIS? (COLON) (p.788)
This condition is commonly first detected on CT; which shows:
1. marked wall thickening up to 30 mm (average 15 mm) with halo
or target appearance
2. ACCORDION SIGN
- characteristic stripes of intraluminal contrast media trapped
between nodular areas of wall thickening
3. Mild pericolonic fat inflammation disproportionate with the marked
colonic wall inflammation
4. Ascites
TOXIC MEGACOLON
63
____ is an infection by the protozoan parasite Entamoeba histolytica.
(p.788)
AMEBIASIS
- the disease is worldwide but particularly
common in South Africa; Central and South
America and Asia
- Encysted amebae are ingested with
contaminated food and water
- the cyst capsule is dissolved in the small
bowel; releasing trophozoites that migrate
to the colon and burrow into the mucosa;
forming small abscesses.
- the infection can spread throughout the
body by hematogenous embolization or
direct invasion.
64
The ___ and ___ are the primary sites of colonic disease in
| amebic colitis. (p.788)
CECUM and RECTUM
- the terminal ileum is characteristically
not involved.
65
____ produces dystentery with frequent bloody mucoid stools.
Barium studies demonstrate a disease that closely mimics
Crohn colitis with aphthous ulcers; deep ulcers; asymmetric
disease and skip area. (p.788)
AMEBIC COLITIS
66
TRUE OR FALSE. (p.788)
Complications of Amebiasis include:
1. Strictures
2. Amebomas consisting of a hard fixed mass of granulation tissue
that may simulate carcinoma
3. Toxic megalcolon
4. Fistulas; particularly following surgical intervention.
TRUE
```
- AMEBIC LIVER ABSCESS results
from the spread of infection through
the portal system and may be
complicated by diaphragm perforation;
pleural effusion and thoracic disease.
```
67
____ is a potentially fatal infection of the cecum and the ascending
colon usually seen in patients who are neutropenic and immuno-
compromised by chemotherapy. (p.788)
TYPHLITIS
(NEUTROPENIC COLITIS)
```
- concentric; often marked; thickening
of the wall of the cecum and the
ascending colon with prominent
pericolonic inflammatory changes
are characteristic.
- patients are at risk for colon
ischemia
```
68
TRUE OR FALSE. (p.788)
ISCHEMIA COLITIS mimics ulcerative colitis and Crohn colitis
both clinically and radiographically.
TRUE
```
- causes include arterial occlusion caused
by arteriosclerosis; vasculitis or arterial
emboli; venous thrombosis due to
neoplasm; oral contraceptives and other
hypercoagulable conditions and low
flow states such as hypotension;
congestive heart failure and cardiac
arrhythmias.
```
69
In ISCHEMIC COLITIS (p.789);
The pattern of involvement generally follows the distribution of a
major artery and is the clue to diagnosis.
The ____ artery supplies the right colon from the cecum to the
splenic flexure.
The ____ artery supplies the left colon from the splenic flexure
to the rectum.
SUPERIOR MESENTERIC ARTERY;
| INFERIOR MESENTERIC ARTERY
70
The ____ and ____ are watershed areas most susceptible to
| ischemic colitis. (p.789)
SPLENIC FLEXURE REGION;
DESCENDING COLON
- early changes include thickening of
the colon wall; spasm and spiculation.
71
In ISCHEMIC COLITIS (p.789);
As blood and edema accumulate within the
bowel wall; multiple nodular defects are
produced in a pattern called "_____".
THUMBPRINTING
- progression of the disease
results in ulcerations; perforation;
scarring and stricture.
72
```
TRUE OR FALSE. (p.789)
In ISCHEMIC COLITIS;
CT demonstrates symmetrical or lobulated
thickening of the bowel wall with an
irregular narrowed lumen.
```
TRUE
```
- TARGET SIGN: submucosal edema
may produce a low-density ring
bordering on the lumen
- Air in the abnormal bowel wall
(pneumatosis) is highly
suggestive of ischemia.
- thrombus may occasionally be
demonstrated within the superior
mesenteric artery or vein.
```
73
AIDS-associated colitis occurs most commonly in AIDS patients with
CD4 lymphocyte counts below ____. (p.789)
below 200
- Causative organisms are most commonly
CMV or cryptosporidiosis;
although the HIV itself may cause ulceration
and colitis.
- right colon disease is most common with
wall thickening and ulceration.
74
TRUE OR FALSE.
RADIATION COLITIS may be indistinguishable radiographically
from early ulcerative colitis. (p.789)
TRUE
- the diagnosis is made by confirmation
of the involved colon being within an
irradiation field.
75
The ___ region is most commonly involved
(RADIATION COLITIS) due to radiation
of pelvic malignancy. (p.789)
RECTOSIGMOID REGION
- colitis is produced by a slowly progressive
endarteritis that causes ischemia and fibrosis.
- radiographic findings include thickened
folds; spiculation; ulceration; stricture;
and occasionally fistula formation
- fibrosis results in a rigid; featureless bowel.
- healing may include formation of
pseudopolyps and postinflammatory polyps
76
____ colon is due to chronic irritation of the mucosa by laxatives
including castor oil; bisacoldyl and senna. (p.789)
CATHARTIC COLON
- the involved colon may be dilated and without
haustra; or narrowed
- the RIGHT COLON is most commonl affected
- bizarre contractions are often observed
- the diagnosis is made by clinical history
77
____ colitis is increasingly common especially in
immunocompromised patients. (p.789)
Imaging findings mimic Crohn disease:
1. marked thickening of the wall of the colon and
terminal ileum
2. markedly enlarged lymph nodes; often with low
central attenuation or calcification.
3. common fistulas and sinus tracts
4. colitis may be segmental or diffuse
5. short strictures may mimic colon cancer
6. thickening of the peritoneum and extensive
abdominal adenopathy suggest the disease.
TUBERCULOUS COLITIS
78
______ is a cause of abdominal pain that may mimic appendicitis;
diverticulitis and colitis. (p.789)
EPIPLOIC APPENDAGITIS
```
- caused by ischemic infarction of
epiploic appendages; often resulting
from torsion.
- patient present with focal abdominal
pain; tenderness and low-grade fever.
```
79
_____ are pedunculated fatty structures that occur in rows on the
external aspect of the colon adjacent to the anterior and posterior
taenia coli.
EPIPLOIC APPENDAGES
- they occur in greatest concentration
in the cecum and the sigmoid colon
sparing the rectum
80
DIAGNOSIS? (colon) (p.789)
diagnosis is usually made by CT showing:
1. 1 to 4 cm ovoid mass with central fat density
and surrounding inflammation abutting the
wall of the colon
2. Hyperdense enhancing rim surround the
mass ("RING SIGN").
3. Inflammatory changes may extend into the
adjacent peritoneum.
4. a central high-attenuation dot is often
present representing the central thrombosed
vessels
5. infracted tissue may eventually calcify.
EPIPLOIC APPENDAGITIS
81
_____ is an acquired condition in which the mucosa and the
muscularis mucosae herniate through the muscularis propria of the
colon wall; producing a saccular outpouching. (p.789)
COLON DIVERTICULOSIS
```
- colon diverticula are classified as false
diverticula because the sacs lack all the
elements of the normal colon wall.
- the condition is rare under age 25;
but increases with age thereafter to
affect 50% of the population over
age 75.
- the major risk factor for diverticulosis
is a low-residue die ; typical of
Western countries.
- the condition is very uncommon
in cultures where a high-residue
diet is the norm; such as African
native populations.
```
82
TRUE OR FALSE.
The formation of diverticular sacs is usually associated with
thickening of the muscularis propria; including both the circular
muscle and the taenia coli. (p.790)
TRUE
```
- severely affected portion of
bowel are usually shortened
in length; resulting in crowding of the
thickened circular muscle bundles.
- muscle dysfunction associated with
diverticulosis may result in pain and
tenderness without evidence of
inflammation
- diverticulosis without diverticulitis
is a cause of painless colonic bleeding
that may be brisk and life-threatening.
```
83
DIAGNOSIS? (colon) (p.790)
CONVENTIONAL ABDOMINAL RADIOGRAPHS demonstrate
gas-filled sac parallel ot the lumen of the colon.
BARIUM STUDIES show diverticula as barium or gas-filled sacs
outside the colon lumen.
COLON DIVERTICULOSIS
```
- sacs vary in size from tiny spikes to
2 cm in diameter.
- most are 5 to 10 mm in diameter.
- they may occur anywhere in the colon
but are most common and usually most
mumerous in the sigmoid colon.
- some sacs are reducible and may
disappear with complete filling of the
lumen
- others may contain fecal residue.
-the associated muscle abnormality
is seen as thickening and crowding
of the circular muscle bands with
spasm and spiked irregular outline
of the lumen.
```
84
```
TRUE OR FALSE.
In colon diverticulosis; (p.790)
CT demonstrates the muscle hypertrophy
as a thickened colon wall and distorted
luminal contour.
The diverticula are shown as well-defined
gas-;fluid- or contrast-filled sacs outside
the lumen.
```
TRUE
85
____ is inflammation of diverticula; usually with perforation and
intramural or localized pericolic abscess. (p.790)
ACUTE DIVERTICULITIS
```
- diverticulitis eventually complicates
approximately 20% of the cases
of diverticulosis.
- clinical signs include painful
mass; localized peritoneal
inflammation; fever and
leukocytosis.
```
86
TRUE OR FALSE. (p.790)
Complications of diverticulitis include bowel obstruction; bleeding;
peritonitis; and sinus tract and fistula formation.
TRUE
```
- Diverticulitis is a less common
cause of colon obstruction than is
colon carcinoma.
- obstruction due to diverticulitis
is often temporarily relieved by
smooth muscle relaxants
such as glucagon
```
87
TRUE OR FALSE. (p.790)
- Colon bleeding is more often associated with
diverticulosis than diverticulitis.
TRUE
88
TRUE OR FALSE. (p.790)
Most diverticular abscesses are quickly walled off and confined;
but free perforation with pus and air in the peritoneal cavity and
diffuse peritonitis may occur.
TRUE
```
- sinus tracts may lead to larger
abscess cavities in the peritoneal
or retroperitoneal compartments
- fistulas are most common to
the bladder; vagina or skin;
but may develop to any lower
abdominal organ including
fallopian tubes; small bowel
and other parts of the colon.
```
89
TRUE OR FALSE (p.790)
Diverticulitis of the right colon may be mistaken clinically for
acute appendicitis.
TRUE
- Diverticulitis is efficiently diagnosed
radiographically by barium enema or CT.
- barium enema examination is considered
safe except when signs of free intraperitoneal
perforation or sepsis are present.
90
DIAGNOSIS? (colon) (p.790)
Hallmarks of this condition on barium enema include:
1. deformed diverticular sacs
2. demonstration of abscess
3. extravasation of barium outside the colon lumen
ACUTE DIVERTICULITIS
```
- the smooth outline of the involved
sacs is deformed by inflammation
and perforation
- the resulting abscess cause extrinsic
mass effect on the adjacent colon
- the colon lumen is narrowed but tapers
at the margins of narrowing in distinction
with the abrupt narrowing of carcinoma
```
91
In ACUTE DIVERTICULITIS (p.790)
Barium leaks into the abscess cavities or forms tracks paralleling
the colon lumen and often connecting multiple perforated sacs
(" ____ ____ sign").
DOUBLE TRACK SIGN
```
- CT excels at demonstrating the
paracolic inflammation and
abscess associated with diverticulitis
as well as complications such as
colovesical fistula.
```
92
```
DIAGNOSIS? (colon) (p.790)
CT findings are:
1. localized wall thickening
2. inflammation of pericolonic fat
3. pericolonic abscess
4. diverticula at or near the site of inflammation
5. common involvement of the adnexa with
fluid collections and fistulas
```
ACUTE DIVERTICULITIS
93
____ imaging studies are often selected as the screening
examination of choice for confirming the presence of; and often
localizing; lower GI bleeding. (p.790-791)
RADIONUCLIDE
| imaging studies
94
Technetium-99m-sulfur colloid or Technetium-99m-red blood cell
studies are capable of detecting bleeding at rates
below _____ mL/min. (p.791)
bleeding at rates BELOW 0.1 mL/min
- a negative scintigraphic study usually
precludes the need for urgent angiography
95
Angiography requires bleeding rates of ___ mL/min or greater.
(p.791)
0.5 mL/min or greater
- however; angiography is more specific than
scintigraphy in demonstrating the anatomic
cause of bleeding and offers the
possibility of nonoperative treatment by
by embolization.
96
TRUE OR FALSE. (in lower GI hemorrhage) (p.791)
Colonoscopy is usually unrewarding because of the
large quantities of sticky; melanotic stool.
Barium enema is not used to evaluate acute
hemorrhage because it usually cannot locate
the source of bleeding and it will interfere with any
subsequently needed angiographic procedure.
TRUE
- CT angiography performed with IV contrast
and without intraluminal contrast shows
promise in the detection of hemorrhage by
documenting intraluminal extravasation of
intravenously administered contrast.
- CT angiography also provides etiological
and anatomic detail.
- This information is useful to the
interventional radiologist or surgeon
as they may be able to identify the culprit
mesenteric vessel or assess the conditiion
of the femoral arteries before attempted
therapy
97
____ refers to ectasia and kinking of mucosal and submucosal
| veins of the colon wall. (p.791)
ANGIODYSPLASIA
```
- the condition results from a
chronic intermittent obstruction
of the veins where they penetrate
the circular muscle layer.
- a maze of distorted;
dilated vascular channels replaces
the normal mucosal structures
and is separated from the bowel lumen
only by a layer of epithelium.
- Angiography demonstrates a tangle
of ectatic vessels without an associated
mass
```
98
TRUE OR FALSE.
Angiodysplasia is acquired and probably related to aging.
The average age of affected patients is 65 years.
TRUE
99
The appendix arises from the ____ aspect of the cecum at the
junction of the taenia coli; approx. _____ cm below the ileocecal
valve.
POSTEROMEDIAL aspect;
| 1 to 2 cm below the ileocecal valve
100
The appendix is a blind-ended tube that is ____ mm in diameter and
approx.___ cm in length; although it may be up to 30 cm long. (p.791)
4 to 5mm in diameter;
approx. 8 cm in length
```
- its mucosa is heavily infiltrated
with lymphoid tissue.
- the appendix is quite variable
in position: it may be pelvic; retrocecal
or retrocolic; and intraperitoneal
or extraperitoneal in location.
```
101
The appendix always arises from the cecum on the ___ side as the
ileocecal valve. (p.791)
SAME SIDE
- a posterior position of the ileocecal valve
indicates a posterior position of the appendix
- on CT; US and MR; the normal appendix appears
as a thin-walled tube less than 6 mm in diameter.
102
_____ is the most common cause of acute abdomen. (p.792)
ACUTE APPENDICITIS
```
- the most difficult patients are
women of childbearing age; in
whom ruptured ovarian cysts and
pelvic inflammatory disease may
mimic acute appendicitis.
- results from obstruction of the
appendiceal lumen
- continued mucosal secretions
cause dilation and increased
intraluminal pressure that impairs
venous drainage and results in mucosal
ulceration
- bacterial infection causes gangrene
and perforation with abscess.
```
103
TRUE OR FALSE. (p.792)
Most periappendiceal abscesses are walled off; but free
perforation and pneumoperitoneum occasionally occur.
TRUE
104
TRUE OR FALSE (p.792)
Conventional films demonstrate an appendiceal calculus
(appendicolith or fecalith) in approximately 14% of patients
with acute appendicitis.
TRUE
```
- an appendicolith is formed by
calcium deposition around a nidus
of inspissated feces.
- the resultant calcification is
usually laminated with a radiolucent
center.
- appendiceal abscess or
periappendiceal inflammation may
result in a visible soft tissue mass in the
right lower quadrant.
- the lumen of the cecum; as outlined
by gas; will be deformed; localized
ileus may be evident.
```
105
TRUE OR FALSE.
In acute appendicitis; (p.792)
Barium enema examination is frequently NONSPECIFIC.
Complete filling of the appendix to its bulbous tip is strong
evidence AGAINST appendicitis.
TRUE
```
- However; nonfilling of the
appendix; as would be expected
with luminal obstruction;
has no diagnostic value of its
own.
- mass impression on the cecum
has many causes besides
appendicitis.
```
106
TRUE OR FALSE.
US; using the graded compression technique; is quite accurate in
providing a definitive diagnosis and is commonly the imaging
technique of choice in women of childbearing age and in children.
TRUE.
Slow grade compression is applied
with a near focus transducer
to the area of maximum
tenderness.
107
The normal appendix has a diameter of less than __ mm
| when compressed. (p.792)
less than 6 mm
108
4 US signs of Acute Appendicitis. (p.792)
```
1. Non-compressible appendix
larger than 6 mm in diameter;
measured outer wall to
outer wall
2. visualization fo a shadowing
appendicolith
3. inflamed periappendiceal fat
becomes more echogenic and fixed
moving with the appendix during
compression
4. color doppler shows increased
vascularity in the wall of the appendix.
```
```
- with perforation; sonography
demonstrates a loculated pericecal
fluid collection; a discontinuous
wall of the appendix and prominent
pericecal fat.
- When the US examination is negative
for appendicitis; an alternate diagnosis;
such as hemorrhagic ovarian cyst; can
frequently be suggested based on visualized
abnormalities.
```
109
___ is the imaging method of choice (acute appendicitis) in men;
in older patients; and when periappendiceal abscess is suspected.
(p.792)
CT
110
Definitive CT diagnosis of acute appendicitis is based on these
three findings. (p.792)
```
1. An abnormally dilated (> 6 mm)
appendix
2. Enhancing appendix surrounded by
inflammatory stranding or abscess
3. Pericecal abscess or inflammatory
mass with a calcified appendicolith
```
```
- an INFLAMMATORY MASS is seen as
indurated soft tissue mass with a
CT density greater than 20 H
- a liquefied mass less than 20H in
CT density is evidence of ABSCESS
- Abscesses larger than 3 cm generally
require surgical or catheter drainage
- Smaller abscesses commonly resolve on
antibiotic treatment alone.
```
111
TRUE OR FALSE. (p.792)
MR competes with US as the diagnostic method of choice for
appendicitis in pregnant women and in children.
TRUE
```
Findings are similar to CT:
1. Dilated appendix larger than
6 to 7 mm diameter
2. Periappendiceal inflammation
seen as high signal intensity on
fat-suppressed T2WI
3. Thickened wall of the appendix
4. Appendicolith seen as focal area
of low signal intensity in the lumen
of the appendix
5. Periappendiceal phlegmon or
fluid collection high in signal intensity
in T2WI.
```
112
______ refers to distension of all or a portion of the appendix
with sterile mucus. (p.793)
- the lumen is obstructed by appendicolith; foreign body;
adhesions; or tumor
- some cases are due to mucinous cystadenomas or
cystadenocarcinomas of the appendix.
MUCOCELE
- Continued secretion of mucus produces
a large (up to 15 cm); well-defined cystic
mass in the right lower quadrant.
- appendiceal dilatation greater than 13 mm
suggests possible mucocele.
- Peripheral calcification may be present.
113
Rupture of the mucocele (in appendix)
| may result in ____. (p.793)
PSEUDOMYXOMA PERITONEI
- gelatinous implants spread throughout
the peritoneal cavity; causing adhesions
and mucinous ascites.
114
________ is the most common tumor of the appendix; accounting
for 85% of all tumors. (p.793)
CARCINOID
115
The _____ is the most common location for carcinoid tumor;
| accounting for 60% of all carcinoids. (p.793)
APPENDIX
```
- most occur near the tip and are round;
nodular tumors up to 2.5 cm in size.
- most are solitary and have less tendency
to metastasize than carcinoids elsewhere
in the GI Tract.
- Carcinoid syndrome is rare; and the
mesenteric reaction seen with small
bowel carcinoid is usually absent
```
116
TRUE OR FALSE.
ADENOMAS occur in the appendix usually in association
with familial multiple polyposis. (p.793)
TRUE
- Isolated adenomas are usually
mucinous cystadenomas associated
with mucocele of the appendix
117
TRUE OR FALSE.
ADENOCARCINOMA of the appendix is rare and is
usually discovered in the clinical setting of suspected appendicitis
in an older adult. (p.793)
TRUE
Imaging demonstrates a soft tissue
mass within or replacing the
appendix.
