Chapter 30 - Mesenteric Small Bowel (CHERI NOTES) Flashcards
(132 cards)
1
Q
TRUE OR FALSE. Disease of the mesenteric small intestine is relatively rare. (p.765)
A
TRUE - A detailed radiographic study of the small bowel is justified only when the clinical suspicion of small bowel disease is high.
2
Q
4 major symptoms of small bowel disease. (p.765)
A
- Colic
- Diarrhea
- Malabsorption
- Bleeding
3
Q
___ is defined as recurrent and spasmodic abdominal pain with periods of relief every 2 to 3 minutes. (p.765)
A
COLIC
4
Q
TRUE OR FALSE. Diarrhea caused by small bowel disease is less urgent than that caused by colon disease. (p.765)
A
TRUE
5
Q
____ is manifest by steatorrhea; foul-smelling stools and weight loss. (p.765)
A
MALABSORPTION
6
Q
_____ is the traditional method for radiographic examination of the small bowel tracked onto a standard upper GI (UGI) series.
(p.765)
A
SMALL BOWEL FOLLOW-THROUGH (SBFT)
- patient is asked to continue drinking
barium while a series of supine abdominal
films are obtained until the terminal ileum
and cecum are filled with barium.
Fluoroscopic examination is then performed. - Visualization of the distal ileum may be improved
with a double-contrast technique by insufflating
the colon with aire (SFBT with peroral pneumocolon)
7
Q
__________ is a more sensitive fluoroscopic method for detailed small bowel examination. (p.765)
- The study may be performed single contrast using approx. 600 mL of barium or double contrast
using 200 mL of barium followed by 1000ML of methylcellulose to advance the barium and distend
the bowel.
A
ENTEROCLYSIS or the SMALL BOWEL ENEMA
- this study provides more uniform distension of the bowel;
even distribution of barium; superior anatomic detail and
shorter overall examination time. - the study is performed by passing a specially designed
12 to 14 French enteroclysis catheter through the mouth
or nose and into the distal duodenum or proximal jejunum. - guidewire is used for directional control of the catheter
during manipulation under fluoroscopy
8
Q
TRUE OR FALSE.
The small bowel lumen and mucosal surface are best demonstrated by barium studies. (p.765)
A
TRUE
9
Q
TRUE OR FALSE.
CT Enteroclysis improves upon barium enteroclysis by demonstrating the extraluminal component of bowel disease; the
mesentery; adjacent solid organs; the peritoneal cavity and the retroperitoneum. (p.765)
A
TRUE
- similar to enteroscopic enteroclysis; an 8 to 13 French
nasojejunal catheter is advanced beyond the ligament
of Treitz under fluoroscopic guidance. - 2L of enteric agent is infused at 100 to 150 cc/min under
fluoroscopic observation.
10
Q
HIGH ATTENUATION CONTRAST AGENTS include ___ and _____. (p.765)
A
4% to 15% water-soluble iodinated contrast agents;
dilute barium solution
- glucagon or other antispasmodic agent is
administered intravenously.
- patient is moved to the table and an additional
500 to 1000 cc of enteric contrast is infused at the
same rate during CT scanning
- thin-slice MDCT allows for high resolution
reconstructions in axial; coronal and sagittal
planes.
11
Q
LOW ATTENUATION ENTERIC AGENTS include ___ and ___. (p.765)
A
water; methylcellulose
12
Q
CT enterography is performed in a manner similar to CT enteroclysis except the 1.5 to 2.0 L of enteric contrast
is given _____ instead of by enteric tuve injection. (p.765)
A
ORALLY
- CT enterography tend to have less reliable and less
complete distension of the small bowel but is easier
to perform and has higher patient acceptance.
13
Q
BIPHASIC AGENTused in MR enteroclysis and MR enterography include ____ (give 4). (766)
low signal in T1WI and high signal intensity in T2WI
A
- water
- methylcellulose
- low-density barium
- polyethylene glycol
- spasmolytic agent reduce peristalsis and motion
artifacts - breath hold fast gradient echo sequences are
obtained in axial; sagittal and coronal planes - IV contrast maybe utilized to assess for
inflammatory hyperenhancement and tumor
vascularity.
14
Q
_____ involves the use of a swallowable video capsule 26 mm long by 11 mm diameter and weighing 4 g. (p.766)
A
CAPSULE ENDOSCOPY
- capsule contains are video camera; four light-emitting
diodes as light source; a radiotransmitter and batteries - patients fast for 10 hours prior to ingesting the capsule.
- a sensor array is placed on the patient’s abdomen and
attached to a portable battery-powered recorder that
can worn around the waist. - capsule is swallowed and color video images recorded
at the rate of 2 per second up to approx. 50thousand
images over an 8-hour battery life span
15
Q
TRUE OR FALSE.
Capsule endoscopy is able to visualize the entire small bowel mucosa and may detect mucosal lesions; ulceers and tumors
missed by imaging examinations. (p.766)
A
TRUE
- significant limitations include limited ability to localize
biopsy; or treat lesions and limited use in patients with
small bowel obstructions or strictures.
16
Q
The mesenteric small intestine is a tube approximately ___ meters long that lies totally within the greater peritoneal cavity.
(p.767)
A
7 meters long
17
Q
____ is arbritrarily defined as the proximal 2/5s of the mesenteric instestine. (p.767)
A
JEJUNUM
18
Q
____ is the distal 3/5s of the mesenteric intestine. (p.767)
A
ILEUM
19
Q
The jejunum and ileum are suspended from the posterior abdominal wall by the _____. (p.767)
A
SMALL BOWEL MESENTERY
- composed of connective tissue; blood vessels and lymphatic
vessels and is covered by peritoneum.; which reflects from the
posterior parietal peritoneum.
20
Q
The root of the small bowel mesentery extends obliquely from the ligamentof treitz; just left of the __ vertebra; to the cecum;
near the right sacroiliac joint (p.767)
A
L2 vertebra
21
Q
On CT; the ___ is defined by its normal vascular structures outlined by fat between loops of bowel. (p.767)
A
MESENTERY
- normal mesenteric lymph nodes may be seen as
soft tissue density nodules 5 mm or less in size. - the concave border of the small bowel loops is the
mesenteric border where the mesentery attaches.
22
Q
The convex border; facing away from the mesentery
is called the ______. (p.767)
A
ANTIMESENTERIC BORDER
- identification of the border involved
by disease can be of diagnostic value.
23
Q
On imaging studies; the _____ has a feathery mucosal patteren; more prominent valvulae conniventes; a wider lumen and
a thicker wall. (p.768)
A
JEJUNUM
24
Q
The ____ has a less feathered mucosal pattern; thinner; less frequent folds; narrower lumen and a thinner wall. (p.768)
A
ILEUM
- has larger and more numerous lymphoid follicles
in the submucosa.
25
____ are finger-like projections that extend from the entire mucosal surface of the small bowel. (p.768)
VILLI
- they are composed of loose connective tissue
of the lamina propria
- tiny capillareis and lymphatic vessels (lacteals)
extend to the submucosal vessels
26
TRUE OR FALSE.
The combination of valvulae conniventes and villi greatly expands the absoptive surface area of the small intestine. (p.768)
TRUE
27
The caliber of the normal small bowel lumen is less than __ cm in the jejunum tapering to less than __ cm in ileum. (p.768)
less than 3 cm;
| less than 2 cm
28
Normal jejunal folds measure ____ mm thick; whereas normal ileum folds measure ____ mm thick. (p.768)
2 to 3 mm thick;
| 1 to 2 mm thick
29
Enteroclysis typically distends the normal jejunum to __ cm and normal ileum to __ cm; with folds appearing 1 mm thinner
in each portion of the mesenteric small bowel. (p.768)
4 cm; 3 cm
30
Normal lymph nodes seen in the mesentery are less than __ mm in diameter. (p.768)
4 mm
31
CT and MR enterography findings that suggest malignant small bowel lesions include____ (give 5). (p.768)
1. Solitary lesions
2. Nonpedunculated lesions
3. Long segment lesions
4. Presence of mesenteric
infiltration
5. presence of enlarged
mesenteric lymph nodes
(>1 cm short axis diameter)
32
____ tumors are the most common neoplasm of the small intestine; accounting for about one-third of all small bowel
tumors. (p.768)
CARCINOID TUMORS
```
- they are considered a
low-grade malignancy
that may recur locally or
metastasize to the lymph
nodes; liver or lung.
```
- arise from the endocrine
cells (enterochromaffin
or Kulchitsky cells) deep
in the mucosa.
- these cells produce vasocative
substance including serotonin
bradykinins
33
About 20% of all carcinoid tumors arise in the small bowel; most commonly in the ____ where 30% are multiple. (p.768)
ILEUM
- only 7%; those with liver metastases; present with
carcinoid syndrome (cutaneous flushing; abdominal
cramps and diarrhea) because the liver inactivates
the vasoaactive substances.
- the tumors grow slowly but cause a marked fibrotic
response of the bowel wall and mesentery because
the serotonin produced by the tumor induces an
intense local desmoplastic reaction.
- complications include stricture; obstruction and
bowel infarction induced by fibrosis of the mesenteric
vessels.
34
TRUE OR FALSE.
CARCINOID TUMORS may be pedunculated and
cause intussusception. (p.768)
TRUE
- radiographic signs of fibrosis and metastases
resemble the findings of Crohn Disease and
overshadow the demonstration of the primary
tumor.
35
DIAGNOSIS? (Small intestines) Barium studies shows:
1. Luminal narrowing
2. Thickened and spiculated folds
3. Separation of bowel loops by mesenteric mass
4. Bowel loops drawn together by fibrosis
5. Primary lesion appearing as small (< 1.5 cm) mural
nodule or intraluminal polyp. (p.768)
CARCINOID TUMOR
36
DIAGNOSIS? (Small intestines) CT and MR findings of:
1. SUNBURST PATTERN of radiating soft-tissue density in the mesenteric fat due to mesenteric fibrosis.
2. Bowel wall thickening
3. Primary lesion appearing as a small; lobulated soft-tissue mass; occasionally with central calcification;
usually in the DISTAL ILEUM
4. Marked contrast enhancement of the primary tumor mass
5. Enlarged mesenteric nodes and liver masses due to metastatic disease. (p.768)
CARCINOID TUMOR
37
AdenoCA of the small bowel is about half as common as carcinoid tumor. (p.768)
It is most frequent in the _____ (50%) and __________ and is uncommon in the _____; where carcinoid is most common.
```
DUODENUM (50%); PROXIMAL JEJUNUM;
DISTAL ILEUM (uncommon site)
```
- most patients are symptomatic at presentation
and 30% have a palpable mass.
38
3 patient conditions where there is increased risk for small bowel carcinoma. (p.768)
1. ADULT CELIAC DISEASE
2. CROHN DISEASE
3. PEUTZ-JEGHERS SYNDROME
- complications include bleeding; obstruction
and intussusception
- prognosis is poor with a 5-year survival of 20%
- metastatic spread is by intraperitoneal seeding;
lymphatic channels to regional nodes; and portal
veins to the liver.
- morphologically; the tumor may be infiltrating
producing strictures; polypoid producing filling
defects; or ulcerating.
39
DIAGNOSIS? (small intestines) Barium studies typically show a characteristic "apple core" stricture of the small bowel. (p.768)
ADENOCARCINOMA OF THE SMALL BOWEL
40
DIAGNOSIS? (small intestines) CT and MR finding demonstrate: (p.768)
1. A solitary mass in the duodenum or jejunum (up to 8 cm in diameter)
2. An ulcerated lesion; or
3. An abrupt or irregular circumferential narrowing of the bowel lumen
with abrupt edges to the wall thickening.
ADENOCARCINOMA OF THE SMALL BOWEL
41
Lymphoma is responsible for about 20% of all small bowel malignant tumors. (p.769)
The ____ is the most common site for extranodal origin of lymphoma; and the ____ is most commonly involved.
GI tract; SMALL BOWEL
- most caes are non-Hodgkin Lymphoma
of B-cell type
- Non-Hodgkin Lymphoma clinically involves
the GI tract in 30% of cases overall.
42
LYMPHOMA is most frequent in the __ ileum where the concentration of the lymphoid tissue is the greatest. (p.769)
DISTAL ILEUM
43
4 Morphologic patterns of involvement of Lymphoma (small intestines). (p.769)
1. DIFFUSE INFILTRATION
2. EXOPHYTIC MASS
3. POLYPOID MASS
4. MULTIPLE NODULES
- multiple sites of involvement are seen
in 10% to 15% of cases.
44
_____ is a feature of lymphoma (small intestines) due to the replacement of the muscularis and destruction of the
autonomic plexus by tumor without inducing fibrosis. (p.769)
ANEURYSMAL DILATION OF THE LUMEN
- as a result; obstruction is uncommon
45
DIAGNOSIS? (small intestines) Barium studies commonly reveal the following: (p.769)
1. Wall thickening with irregular; distorted folds due to the submucosal infiltration of cells.
2. Fold thickening may be smooth and regular in early stages due to lymphatic blockage in the mesentery.
3. Folds become effaced in later stages with greater cell infiltration into the bowel wall
4. Narrowed; widened or normal lumen
5. Cavitary lesions containing fluid and debris
6. Polypoid masses that may cause intussusception
7. Rare multiple filling defects that are larger than 4 mm; variable in size and non-uniform in
distribution.
- shallow ulceration is common
LYMPHOMA
46
DIAGNOSIS? (small intestines) CT demonstrates: (p.769)
1. Circumferential wall thickening involving a long segment of small bowel
2. Effacement of folds
3. Mucosal nodularity
4. Eccentric wall thickening
LYMPHOMA
47
TRUE OR FALSE.
EXOPHYTIC LYMPHOMA is generally of uniform soft-tissue density and enhances little; if any; with IV contrast
administration. (p.769)
TRUE
- This is a DIFFERENTIATING FINDING in
comparison with GI stromal tumors (GISTs) and
adenocarcinoma; which usually enhance
prominently.
- CT and MR readily demonstrates associated
findings of lymphoma including mesenteric
and retroperitoneal adenopathy and
hepatosplenomegaly.
48
TRUE OR FALSE.
In lymphoma (small intestines); the mesentery may show a large confluent mass encasing multiple bowel loops or enlarged
individual nodes. (p.769)
TRUE
49
Radiologic sign which refers to the sparing of rind of fat surrounding mesenteric vessels that are encased by lymphomatous
nodes. (p.770)
SANDWICH SIGN
- mesenteric lymphoma
50
BURKITT LYMPHOMA in N.America usually presents with intestinal involvement; especially of the ___ area in children and
and young adults. (p.770)
ILEOCECAL AREA
- the malignancy is aggressive; with rapid
doubling time and poor prognosis;
- imaging studies show bulky tumors
51
TRUE OR FALSE.
AIDS-related lymphoma is an aggressive high-grade non-hodgkin lymphoma with poor prognosis. (p.770)
- extranodal involvement; including small bowel lymphoma is common.
TRUE
```
- Adenopathy may be caused by lymphoma;
Kaposi sarcoma or Mycobacterium avium-
intracellulare infection.
- The radiographic findings are identical to those
seen in immunocompetent patients.
```
52
TRUE OR FALSE.
| NODULAR LYMPHOID HYPERPLASIA may involve the entire small bowel. (p.770)
The condition is differentiated from lymphoma
by the uniform small size of the nodules
(2 to 4 mm) and even distribution through the
area of involvement.
53
Lymphoid hyperplasia confined the terminal ileum and proximal colon is usually considered incidental and may be related
to _____. (p.770)
RECENT VIRAL INFECTION
- diffuse lymphoid hyperplasia is associated with
hypogammaglobulinemia; esp. low IgA.
54
Metastases to the small bowel are common. (p.770)
The 2 most frequent routes are by ____; usually in the __ border
and by _____ which usually implants on the ___ border.
```
PERITONEAL SEEDING (MESENTERIC BORDER);
HEMATOGENOUS SPREAD (ANTIMESENTERIC BORDER)
```
55
Intraperitoneal implantation on the small bowel serosa is most commonly due to _____ in women and ___;____ and ___
in men. (p.770)
```
OVARIAN CARCINOMA (in women);
PANCREATIC CARCINOMA (in men)
```
56
TRUE OR FALSE. (p.770)
The mesenteric border of the small bowel is favored by the flow of fluid along the small bowel mesentery from the left
upper to the right lower abdomen.
TRUE
57
Implantation (small bowel mets) is most common along the ___; ___ and ___. (p.770)
1. TERMINAL ILEUM
2. CECUM
3. ASCENDING COLON
- peritoneal implants on the parietal peritoneum; and omentum
(omental cake); as well as in the pouch of Douglas are demonstrated
by CT.
- Barium studies demonstrate nodules and tethering of folds due to
mesenteric fibrosis
58
```
Hematogenous metastases (in small bowel) are deposited along the __ border where the submucosal blood vessels
arborize. (p.770)
```
ANTIMESENTERIC BORDER
- common primary malignancies are melanoma; lung; breast
and colon carcinoma and embronal cell carcinoma of the testes
- imaging studies demonstrate mural nodules of uniform or
varying size anywhere in the small bowel.
- they may appear as target lesons or ulcerate or cavitate.
59
Direct extension to involve the small bowel is seen with malignancies of the ____ and ____. (p.770)
PANCREAS and COLON
60
Kaposi Sarcoma in AIDS patients commonly involves the __ intestine. (p.770)
SMALL INTESTINE
- about half of the patients with skin lesions have intestinal
lesions as well
- Barium studies demonstrate multiple mural
nodules; often centrally umbilicated
- CT demonstrates mesenteric; retroperitoneal
and pelvic adenopathy.
61
TRUE OR FALSE.
Approximately 20% to 30% of GISTs arise thoughout the small intestine and tend to be more aggressive than gastric tumors
of the same size. (p.770)
TRUE
-tumors present with obstruction or intestinal bleeding
62
DIAGNOSIS? (small intestines)
Barium studies show a well-defined submucosal mass with smooth mucosa.
Tumors that exceed 2 cm in size tend to ulcerate whether they are benign or malignant. (p.770)
TRUE
on CT:
- BENIGN GISTs are homogenous with attenuation similar to muscle
- MALIGNANT GISTs tend to be larger (>5 cm) and heterogenous with
prominent areas of low-attenuation necrosis and hemorrhage.
-Nodal metastases are uncommon
- Calcifications are infrequent
63
MR shows the solid portions (of GIST ins small intestines) to be of __ signal on T1WI and __ signal on T2WI.
T1WI: low signal; T2WI: high signal
- Solid areas show distinct contrast enhancement
- hemorrhage show characteristic MR signal dependent
on its age.
64
Adenoma accounts for about 20% of benign small bowel neoplasms. (p.770)
It is more common in the _____ than in the mesenteric small intestine.
DUODENUM
- The tumor is a benign proliferation of the
glandular epithelium and has the potential for
malignant degeneration.
- barium studies demonstrate an intraluminal
polyp with a finely lobulated surface.
65
Lipoma is most common in which part of the small intestines ? (p.770)
ILEUM
- tumor arises from the fat of the submucosa
- account fot about 17% of benign small bowel tumors
- most are asymptomatic incidental findings; although
some cause bleeding or intussusception
- CT demonstration of a fat density
(-50 to -100 H) tumor is diagnostic.
66
TRUE OR FALSE.
| HEMANGIOMA (in small intestines) is usually solitary submucosal; projecting into the lumen as a polyp. (p.771)
TRUE
- about 2/3rds present with bleeding
- barium studies demonstrate a small polyp
- the occasional presence of a calcified phlebolith
suggests the diagnosis.
- they account for less than 10% of benign small
bowel tumors.
67
_____ syndromes cause multiple polypoid lesions of the small bowel. (p.771)
POLYPOSIS SYNDROMES
- differential diagnosis includes metastases; lymphoma;
nodular lymphoid hyperplasia; Kaposi
sarcoma and carcinoid tumors
68
```
_____ syndrome is an autosomal dominant inherited condition consisting of multiple hamartomatous polyps in the
small intestine (most common); colon and stomach associated with melanin freckles on the facial skin;
palmar aspects of the fingers and toes; and mucous membranes. (p.771)
```
PEUTZ-JEGHERS SYNDROME
- hamartomaous polyps are a nonneoplastic; abnormal proliferation of
all three layers of the mucosa; epithelium;
lamina propria and muscularis mucosae.
- the POLYPS are most common in the
JEJUNUM; are usually pedunculated; and
are variable in size up to 4 cm.
- patients are at increased risk for intussuception; GI tract adenocarcinoma and extraintestinal malignancy
(breast; pancreas and ovary).
- barium studies demonstrate myriad polyps
in involved areas of small intestine; separated
by normal bowel segments
69
____ syndrome involves the small bowel in about half the cases with multiple inflammatory polyps. The colon and stomach
are always involved. (p.771)
CRONKITE-CANADA syndrome
70
_____ syndrome of inherited adenomatous polyposis coli usually includes a few adenomatous polyps in the small bowel. (p.771)
GARDNER syndrome
71
TRUE OR FALSE.
| JUVENILE GI POLYPOSIS is most common in the colon; but occasionally involves the small bowel.
TRUE
- Inflammatory polyps containing cysts
filled with mucin develop secondary
to chronic irritation.
- most are round; smooth and
pedunculated
72
Ascariasis worms mature in the small bowel; espescially in the ___ and may reach 15 to 35 cm. (p.771)
JEJUNUM
-Ascariasis is caused by infestation with the
round-worm Ascaris lumbricoides
- Ascariasis is found worldwide but is
common in Asia and Africa.
- Infestation is acquired by ingesting food or water
contaminated with Ascariasis eggs.
- New generations of infective ova are excreted in
feces
- A large bolus of worms may obstruct the small
bowel; especially in children or cause intussusception
73
Ascariasis eggs hatch in the ____. (p.771)
SMALL BOWEL
- larvae penetrate the wall and migrate
through the vascular system to the lungs;
where they molt and grow before migrating
up the bronchi and trachea to the larynx
where they are again swallowed.
74
TRUE OR FALSE.
| Barium demonstrates worms as LONG LINEAR FILLING DEFECTS. (p.771)
TRUE
- worms can be identified on conventional
abdominal radiographs in 70% of cases
- Barium ingested by the worms may be
seen In their intestinal tract as a long;
string-like white line.
75
TRUE OR FALSE.
| Masses arising in the small bowel mesentery frequently present as PALPABLA ABDOMINAL MASS. (p.771)
TRUE
```
- the mesenteric fat may be infiltrated by
edema; hemorrhage or inflammatory
cells.
- the disorders may be diseases of the
small intestine or be primary to the
mesentery itself.
- CT; US and MR provide the most
diagnostic information.
```
76
Normal mesenteric lymph nodes are less than ___ mm in short axis diameter. (p.771)
LESS THAN 5 mm
```
- enlarged lymph nodes are associated with
neoplastic; inflammatory and infectious
disease and may be the only imaging
manifestation.
- number and distribution of lymph nodes
is as important as size.
- ENLARGED LYMPH NODES may represent
lymphoma or metastatic disease from the
breast; lung; pancreas or GI tract
- INFLAMMATORY LYMPH NODES are
associated with appendicitis; diverticulitis;
pancreatitis or cholecystitis.
-INFECTIOUS LYMPHADENOPATHY is
associated with Yersinia enterocolitica
infections of the terminal ileum; TB; HIV
and Whipple disease.
```
77
____ causing bulky adenopathy is the most common solid mesenteric mass. (p772)
LYMPHOMA
```
- confluent adenopathy surrounds the
mesenteric vessels and fat producing the
"sandwich sign"
- adenopathy is commonly present in the
retroperitoneum and elsewhere
- the sandwich sign is specific to
mesenteric lymphoma
```
78
TRUE OR FALSE.
METASTASES may implant in the mesentery and produce a large mesenteric mass without impingement of the bowel lumen
or may implant adjacent to the bowel narrowing the bowel lumen. (p.772)
TRUE
```
- CARCINOID and SMALL BOWEL ADENOCA
metastases produce a prominent
desmoplastic reaction in the mesentery;
whereas MELANOMA produces no
mesenteric retraction.
```
79
____ tumors (_____) are benign but locally aggressive; solid; fibrous mesenteric tumors.
They may be solitary (28%) or multiple (72%) and associated with Gardner syndrome.
Tumors commonly recur after surgical resection. (p.772)
MESENTERIC DESMOID TUMORS
(MESENTERIC FIBROMATOSIS)
```
- US and CT demonstrate a homogenous
solid mass with well-defined (68%) or
infiltrative borders
- attenuation is similar to muscle
- tumors commonly also occur within
the muscles of the anterior abdominal
wall or in the psoas muscles.
```
80
TRUE OR FALSE.
GISTs may arise primarily in the mesentery or omentum or may be found as metastases
from tumors arising elsewhere.
TRUE
- on CT; tumors appear as large; well-defined
masses; with prominent areas of low
density representing hemorrhage and
necrosis
81
___ are lymphangiomas that arise in the root of the small bowel mesentery.
Most are thin-walled and multiloculated with internal fluid that may be chylous; serous or bloody. (p.772)
MESENTERIC CYSTS
- on US: demonstrates a well-defined cyst
with internal debris; and fluid-debris or
fluid-fat levels.
- on CT: cystic mass; displacing loops of small
bowel anteriorly and laterally.
- on MR:
serous CYST CONTENTS - T2WI hyperintense;
T1WI hypointense.
chylous or hemorrhagic CYST CONTENTS -
T1WI hyperintense
82
______ cyst is a congenital; partial or complete replica of the small bowel. (p.772)
GI DUPLICATION CYST
-most arise from the DISTAL SMALL BOWEL and may communicate with the normal intestinal lumen at one or both ends; or not all.
- they are lined by interstitial epithelium
- US; CT and MR reveal a thick-walled cyst with usually serous contents
- malignancies (adenocarcinoma) may arise
within duplication cysts.
83
TRUE OR FALSE.
MESENTERIC TERATOMA is heterogeneous with cystic and solid components.
Demonstration of calcium or fat is a clue to radiographic diagnosis. (p.772)
TRUE
84
_____ is an uncommon inflammatory condition affecting the root of the mesentery with variable inflammation; fat necrosis
and fibrosis.
CT shows soft tissue infiltration of the mesentery; the so-called "MISTY MESENTERY". (p.772)
SCLEROSING MESENTERITIS
- lesions may be solitary or multifocal within the mesentery
- cause is unknown; but the disease is
associated with other idiopathic inflammatory
disorders including retroperitoneal fibrosis
and sclerosing cholangitis.
- patients commonly present with abdominal pain
85
Five rules of DIFFUSE SMALL BOWEL DISEASE: (p.772)
RULE #1: ___ means small bowel obstruction or dysfunction
of small bowel muscle.
RULE #2: ____ means infiltration of the submucosa
RULE #3: ____ means infiltration by fluid (edema or blood)
RULE #4: ____ means infiltration by cells or nonfluid material
RULE #5: The specific diagnosis requires matching the small
bowel pattern with the clinical data.
RULE #1: Dilatation of the small bowel lumen
RULE #2: Thickening of small bowel folds
RULE #3: Uniform; regular straight thickening
RULE #4: Irregular; distorted; nodular thickening
86
TRUE OR FALSE.
The hallmark of mechanical small bowel obstruction is a point of transition between dilated bowel and nondilated bowel
at the site of obstruction. (p.772)
TRUE
- with muscle dysfunction; the small bowel dilatation
is diffuse with no transition point.
- if no coexisting mucosal disease is present; the small
bowel folds are straight and regular.
87
TRUE OR FALSE.
Thickened small bowel: Irregular and distorted is the most difficult category of abnromality; because many condition are
unsual. (p.773)
TRUE
- some conditions are included in several categories.
EARLY CROHN DISEASE is characterized by edema and
regular folds.
More ADVANCE CROHN DISEASE has inflammatory cell
infiltrate and irregular folds.
88
___ and ___ are the two most commonly encountered small bowel diseases. (p.773)
LYMPHOMA and CROHN DISEASE
89
_____ produces atrophy of the muscularis of the small bowel by the process of progressive collagen deposition resulting in
flaccid; atonic and dilated bowel.
SCLERODERMA
- the valvulae conniventes are normal or thinned
- a "hide-bound" appearance of thinned
folds tethered together is produced by the
contraction of the longitudinal muscle
layer to a greater extent than the circular muscle layer.
90
TRUE OR FALSE.
Excessive contraction of the mesenteric border of the small bowel results in the formation of mucosal sacculations along the
antimesenteric border.
TRUE
91
TRUE OR FALSE.
| In scleroderma; The jejunum and duodenum are more severely involved than the ileum. (p.774)
TRUE
- The diagnosis is confirmed by skin changes
and characteristic involvement of the
esophagus
- Malabsorption eventually occurs
92
TRUE OR FALSE.
| Adult celiac disease (nontropical sprue) presents with malabsorption; steatorrhea and weight loss.
TRUE
```
- the MUCOSA becomes flattened and
absorptive cells decrease in number;
villi disappear
- the submucosa; muscularis and serosa
remain normal
```
93
_____; an insoluble protein found in wheat; rye; oats and barley acts as a toxic agent to the small bowel mucosa. (p.774)
GLUTEN
```
- findings and symptoms resolve with
a strict gluten-free diet. (ADULT
CELIAC DISEASE)
- complications of celiac disease include
small bowel intussusception; lymphoma;
ulcerative jejunoileitis; cavitating lymph-
adenopathy syndrome and pneumomatosis
intestinalis.
```
94
4 classic radiographic findings of ADULT CELIAC DISEASE (nontropical sprue). (p.774)
1. Dilated small bowel
2. Normal or thinned folds
3. A decrease number of folds per inch
in the jejunum
4. An increased number of folds per inch
in the ileum (> or = to 5)
- findings are best demonstrated by
enteroclysis
- five or more folds per inch in the jejunum
make the diagnosis unlikely.
- fluid excess is often evident in the ileum
- distention of small bowel loops with
increased volume of intraintestinal fluid
is seen on conventional MDCT
95
3 CT enterography findings of ADULT CELIAC DISEASE (nontropical sprue). (p.774-775)
1. Reversed jejunoileal fold pattern with
loss of folds in the jejunum and increased
number of folds in the ileum
2. mesenteric lymphadenopathy
3. engorgement of mesenteric vessels.
- transient intussusceptions may be observed
96
TRUE OR FALSE.
TROPICAL SPRUE has similar clinical and radiographic findings as nontropical sprue but is confined to India; the Far East; and
Puerto Rico. The disease responds to the administration of folate and antibiotics. (p.772)
TRUE
97
Lactase is required within the absorptive cells of the jejunum to properly digest ______. (p.775)
DISACCHARIDES
- Several population groups; including Chinese; Arabs; Bantu
and Eskimos; may become totally deficient in lactase during
adult life.
- Secondary lactase deficiency may develop with alcoholism;
Crohn disease and drugs such as neomycin
- the nondigested lactose in the small bowel causes
increased intraluminal fluid and dilated
small bowel with normal folds
98
_____ may result from embolism or thrombosis of the superior mesenteric artery or vein.
Patients may present with an acute abdomen or vague symptoms. (p.775)
INTESTINAL ISCHEMIA
- ARTERIAL OCCLUSION may be due to
embolus; vasculitis; trauma or adhesions
- VENOUS THROMBOSIS results from
hypercoagulability states (neoplasms
and oral contraceptives); inflammation
(pancreatitis; peritonitis and abscess) or
stasis (portal HTN and congestive heart failure).
99
In INTESTINAL ISCHEMIA; Conventional radiographs demonstrate __; ___ and in some cases_____. (p.775)
1. Gaseous distension
2. Thickened mucosal folds
(thumbprinting)
3. Intramural or portal venous gas
100
Diagnostic imaging of choice for INTESTINAL ISCHEMIA? (p.775)
MDCT with IV contrast
101
DIAGNOSIS? (p.775) CT findings show:
1. Diffuse thickening fo the bowel wall; usually to 8 to 9 mm; may occur rarely exceeding 15 mm
2. Thinning of the bowel wall may occur in acute arterial occlusion caused by loss of intestinal
muscle tone and tissue volume with vessel contriction
3. Low attenuation of the bowel wall is caused by edema
4. High attenuation of the bowel wall is caused by intramural hemorrhage
5. Lack of or decreased bowel wall enhancement is highly specific for acute ischemia
6. Pneumatosis of the thickened bowel wall may indicate transmural infarction
7. Dilatation of the bowel wall occurs with adynamic ileus
8. Mesenteric vessels with emboli or thrombi fail to enhance following IV contrast
administration
9. Mesenteric fat stranding and ascites are commonly present
INTESTINAL ISCHEMIA
102
_____ is the most radiosensitive organ in the abdomen. (p.775)
SMALL BOWEL
- RADIATION ENTERITIS occurs when large
doses of radiation are given to the
adjacent organs.
103
TRUE OR FALSE. (p.775-776)
In RADIATION ENTERITIS; long segment of bowel may be involve; with thickening of folds and bowel wall.
Peristalsis is impaired.
TRUE
```
- Progressive fibrosis leads to tapered
strictures commonly involving long
segments
- the bowel mey be kinked and obstructed
by adhesions
- fistulas to the vagina or other organs may
also result
- CT demonstrates wall thickening and
increased density of the mesentery; and
fixation of bowel loops
```
104
______ refers to the gross dilation of the lymphatic vessels in the small bowel mucosa and submucosa.
The primary form is a congenital lymphatic blockage; often associated with assymmetric edema of the extremities. (p.776)
LYMPHANGIECTASIA
- despite being congenital; symptoms often do not occur
until young adulthood.
- patients present with protein-losing enteropahty;
diarrhea; steatorrhea and recurrent infection.
105
_____ refers to lymphatic obstruction due to radiation; congestive heart failure; or mesenteric node involvement by malignancy
or inflammation. (p.776)
SECONDARY LYMPHANGIECTASIA
- the diagnosis is confirmed by jejunal biopsy
106
DIAGNOSIS ? (small intestines) (p.776). Barium study findings include:
1. diffuse fold thickening that is most pronounced in the jejunum
2. increased intraluminal fluid
3. groups of tiny (1 mm) nodules due to distended villi.
The pattern closely resemble Whipple Disease.
LYMPHANGIECTASIA
- CT helps the differentiation by revealing
thickening of the bowel wall and
mesenteric adenopathy in secondary
lymphangiectasia
107
Eosinophilic gastroenteritis virtually always affects the gastric _____; as well as all or part of the small bowel.
Intense infiltration of eosinophils in the lamina propria causes thickening of the bowel wall and mucosal folds; often with
luminal narrowing. (p.776)
ANTRUM
- Barium studies show thickened and
straighthened folds. Thickening of the
bowel wall is evidence by wide separation
between bowel loops.
- CT shows thickened distorted folds in the
distal stomach and proximal small bowel.
- most patients have a history of allergic
disorders
- the disease is self limited; but recurrences
are frequent.
108
____ is a disease complex associated with extracellular infiltration of an amorphous protein material in body tissues. (p.776)
AMYLOIDOSIS
- the disease may be primary or associated with
multiple myeloma (10% to 15%); rheumatoid
arthritis (20% to 25%); or tuberculosis (50%)
- most cases are systemic; but 10% to 20%
are localized
109
Most common site of GI involvement in Amyloidosis. (p.776)
SMALL BOWEL
- Amyloid deposits are seen thoughout the
wall of the small bowel; esp.within the walls
fo small blood vessels resulting in ischemia
and infarction.
- deposits in the muscularis impair
motility
- diffuse; irregular thickened folds may be
seen throughout the small bowel
-Nodules are sometimes present.
110
TRUE OR FALSE.
In AMYLOIDOSIS; CT demonstrates symmetric wall thickening of a affected bowel
without luminal dilatation or hypersecretion. (p.776)
TRUE
- Small mesenteric lymph nodes may be
evident. Diagnosis is confirmed by biopsy.
111
_____ is a proliferation of mast cells in the skin; bones; lymph nodes and GI tract. (p.776)
- Urticaria pigmentosa is the characteristic skin manifestation.
SYSTEMIC MASTOCYTOSIS
- Osteoblastic bone changes are found in 70% of
cases
- Lymphadenopathy and hepatosplenomegaly
are often present.
- The bowel wall and mucosal folds are thickened;
and mucosal nodules up to 5 mm size are often
evident.
112
___ is an uncommon systemic disorder affecting the GI tract; joints; CNS and lymph nodes. (p.776)
The disease is caused by Whipple bacilli; gram-positive; rod-shaped bacteria that are found within macrophages in many organs
and tissues. (p.776)
WHIPPLE DISEASE
113
In AIDS enteritis; ___ and ___ are protozoans that may infest the proximal intestine and cause a cholera-like diarrhea with
life-threatening fluid loss. (p.776)
CRYPTOSPORIDIUM and ISOSPORA BELLI
- Barium studies show thickened folds
and marked increased fluid.
114
TRUE OR FALSE.
Cytomegalovirus causes disease in the small bowel and colon as well as the lungs; liver and spleen.
Mucosal ulceration with bleeding and perforation are the major intestinal manifestations. (p.776)
Barium studies show thickened folds;
| loop separation; ulcers and fistulae.
115
TRUE OR FALSE.
Mycobacterium avium-intracellulare is a common systemic
infection in AIDS; involving lung; liver; spleen; bone marrow;
lymph nodes and intestinal tract. (p.776)
TRUE
```
- Barium studies show thickened nodular
folds with a sand-like mucosal pattern
- CT demonstrates retroperitoneal and
mesenteric adenopathy and focal lesions
in the liver and spleen.
```
116
TRUE OR FALSE.
Candida; Amoeba histolytica; Giardia; Strongyloides; Herpes simplex and Campylobacter may also occur in AIDS patients.
(p.776)
TRUE
117
TRUE OR FALSE.
CROHN DISEASE is a common inflammatory disease of uncertain etiology that may involve the GI tract from the esophagus to the
anus. The disease is characterized by erosions; ulcerations; full-thickness bowel wall inflammation and formation of noncaseating
granulomas. (p.776)
TRUE
- patient present; usually in their teens;
twenties and thirties; with diarrhea;
abdominal pain; weight loss and often
fever.
- the typical course is one of remissions;
relapse and progression of disease
- patterns of GI involvement include
colon and terminal ileum (55%);
small bowel alone (30%); colon alone (15%)
and proximal small bowel without
terminal ileum (3%)
118
DIAGNOSIS? (small bowel) (p.776 to 777)
Radiographic hallmarks of this disease include:
1. Aphthous erosions
2. Confluent deep ulcerations
3. Thickened and distorted folds
4. Fibrosis with thickened walls; contractures and stenosis
5. Involvement of the mesentery
6. Asymmetric involvement both longitudinally and
around the lumen
7. Skip areas of normal intervening bowel between
disease segments
8. Fistula and sinus tract formation.
CROHN DISEASE
- APHTHOUS ULCERS are shallow; 1 to 2 mm depressions
usually surrounded by a well-defined halo
- DEEP ULCERATIONS are larger and often linear;
forming fissures between nodules of elevated
edematous mucosa ("cobblestone patter")
- fibrosis and progressive thickening of the
bowel wall narrows the lumen; particularly of the
terminal ileum; producing the "string sign"
119
4 findings indicative of active inflammation in CROHN DISEASE. (p.777)
1. Wall thickening (>3 mm)
2. Layered pattern of wall enhancement
3. the "COMB SIGN" of fibrofatty infiltration
around inflamed bowel segments with
engorged mesenteric vessels forming the
comb
4. on MR high-signal intensity of the
thickened bowel wall on T2WI with fat
saturation.
120
TRUE OF FALSE.
Fistulae are formed in 19 % of patients with small bowel disease. (CROHN DISEASE)
Most frequent are ILEOCOLONIC AND ILECOCECAL; but enterocutaneous; enterovesical;
and colovesical fistulae are also common. (p.778)
TRUE
```
- Fistulae are abnormal communications
between two epithelial-lined organs
- derangements of intestinal absorption
cause megaloblastic anemia (vitamin B12
deficiency) and an increased incidence of
gallstones and renal stones.
```
121
TRUE OR FALSE.
Y. entorocolitis infection causes acute enteritis with abdominal pain; fever and often bloody diarrhea that mimics acute
appendicitis or acute Crohn disease.
- children and young adults are most often affected. (p.778)
TRUE
- caused by infection with gram positive
bacilli; Y. enterocolitica or Y. pseudoTB
- the infection runs a self-limited course of
8 to 12 weeks
- diagnosis is confirmed by stool culture
122
Radiographic findings of Y. enterocolitis are most pronounced in the _______ of the ileum. (p.778)
DISTAL 20 cm of the ileum
```
- they include aphthous ulcers; nodules
up to 1 cm in size; wall thickening and
thickened folds that become effaced
with increasing edema
- nodular lymphoid hyperplasia may
appear during the resolution stage
```
123
TRUE OR FALSE.
| Campylobacter fetus jejuni infection is clinically and radiographically similar to Y.enterocolitis (p.778)
TRUE
- the disease usually lasts 1 to 2 weeks;
but relapses are common
- diagnosis is by stool culture
124
_____ is a multisystem disease due to a small vessel vasculitis that affects eyes; joints; skin; CNS and intestinal tract. (p.778)
BEHCET DISEASE
- prominent clinical features include relapsing
iridocyclitis; mucocutaneous ulcerations; vesicles;
pustules and mild arthritis
- intestinal disease most commonly involves the
ILEOCECAL REGION; where CROHN DISEASE is
closely mimicked with aphthous erosions;
deep ulceration; stenosis and fistula formation
- complications include bowel perforation and
peritonitis
125
TUBERCULOSIS presents as peritonitis or focal infection of the gut; most commonly involving the ______ area;
closely mimicking Crohn disease
- less than half of the patients have concurrent evidence of pulmonary TB
ILEOCECAL AREA
- barium studies demonstrate inflamed mucosa
with transverse and stellate ulcers
- the affected bowel becomes rigid and
narrowed with nodular mucosa
- the ileocecal valve is stiff and gaping with
narrowed terminal ileum and cecum
- CT shows characteristic findings of mesenteric
adenopathy; high-density ascites and
peritoneal thickening accompanying the
bowel wall thickening
126
Small bowel diverticula are most common in the ____ along the mesenteric border.
They are outpouchings of MUCOSA through the bowel wall and between the leaves
of the mesentery.
JEJUNUM
- They are commonly multiple and often asymptomatic.
However; because of stasis of bowel contents within them; bacterial
overgrowth may occur resulting in deconjugation of
bile salts and malabsorption.
- Vitamin B12 absorption may also be impaired; resulting in
megaloblastic anemia.
- additional complications include obstruction; acute diverticulitis;
hemorrhage and volvulus.
127
```
The diverticulum (in small bowel diverticula) LACKS MUCOSAL FOLDS
and does not contract because of the lack of _____ within its wall.
(p.778)
```
MUSCLE
*small bowel diverticula:
- conventional radiographs may reveal
featureless ovoid collections of air
- barium studies shows the outpouchings;
most with a neck smaller in diameter than
the outpouching itself
- On CT; diverticula appear as as discrete;
round or ovoid; structures outside the
expected lumen of the small bowel
- they may be filled with air; fluid or contrast
and have a thin smooth wall
128
_____ is the most common congenital anomaly of the GI tract; present in 2% to 3% of the population. (p.778)
MECKEL DIVERTICULUM
- the diverticulum varies from 2 to 8 cm in length
129
Location of Meckel diverticulum? (p.778)
ANTIMESENTERIC BORDER OF THE ILEUM
UP TO 2 m from the ileocecal valve.
- the tip of the diverticulum may be attached
to the umbilicus by a remnant of the vitelline
duct.
- ectopic gastric mucosa is present in up to
62% of cases.
- peptic secretions may cause ulceration and
bleeding
- other complications are intussusception;
volvulus and perforation
130
TRUE OR FALSE.
Radionuclide (Tc-99m-pertechnate) scanning for ectopic gastric mucosa is the test of choice
but is less reliable in adults than in children and is negative when the diverticulum does
not contain gastric mucosa
TRUE
131
____ is the best method to demonstrate Meckel Diverticulum; which appears as a blind sac attached to the antimesenteric
border of the ileum. (p.778)
ENTEROCLYSIS
- on CT; Meckel diverticulitis appears as a blind-ending
pouch of variable size and wall thickness; with
inflammatory changes in the adjacent mesentery
132
_____ or ____ are outpouchings along the antimesenteric border of the small bowel that result from disease of the small bowel.
They occur most commonly in association with Crohn Disease or scleroderma. (p.779)
PSEUDODIVERTICULA or SACCULATIONS
- with fibrosis and contraction of the
mesenteric border of the bowel; the
unsupported antimesenteric border becomes
pleated and forms sacculations.
