Mesenteric small bowel Flashcards
small bowel disease is usually manifest by four major symptoms
colic, diarrhea, malabsorption, bleeding
defined as recurrent and spasmodic abdominal pain with periods of relief every 2 to 3 minutes
colic
true or false: diarrhea cause by small bowel disease is less urgent than that caused by colon disease
true
size of enteroclysis catheter
12 to 14 Fr
single contrast technique in fluoroscopic enteroclysis use how many ml of barium
600 cc
double contrast technique in fluoroscopic enteroclysis use how many ml of barium and methylcellulose
200 cc barium, 1000 cc of methylcellulose
size of nasojejunal catheter used in CT enteroclysis
8 to 13 Fr
high attenuation contrast agents include how many percent of water soluble iodinated contrast with dilute barium
4-15%
low attenuation contrast include
water and methylcellulose
in CT enteroclysis, 2 liters of enteric agent is infused at what rate
100 to 150 cc/min
imaging technique that is particularly important in the study of patients with Crohn disease who are young and undergo many imaging examinations
MR enteroclysis and MR enterography
enteric agents use in MR enteroclysis or MR enterography
biphasic agents (water, methylcellulose, low-density barium and polyethylene glycol)
agents that may be given during MR to reduce peristalsis and motion artifacts
spasmolytics
bowel wall thickening of > 2 cm indicates a benign or malignant process?
malignant
length of small bowel
7 m
proximal 2/5 of mesenteric intestine
jejunum
distal 3/5 of mesenteric intestine
ileum
root of small bowel mesentery extends obliquely from the
ligament of Treitz, just left of L2 vertebra, to the cecum near the right sacroiliac joint
normal mesenteric lymph nodes may be seen as soft tissue nodules with size of
5 mm or less
concave border of mesentery is called
mesenteric border
convex border of mesentery is called
antimesenteric border
luminal diameter of jejunum
< 3 mm
normal fold thickness of jejunum
2- 3 mm
diameter of lumen of jejunum on enteroclysis
< 4.0 cm
normal fold thickness of jejunum on enteroclysis
1-2 mm
number of jejunal folds
4-7 per inch
depth of folds of jejunum
8 mm
thickness of jejunal bowel wall
3 mm
diameter of lumen of ileum
< 2 cm
normal fold thickness of ileum
< 2.0 cm
diameter of lumen on enteroclysis of ileum
< 3.0 cm
normal fold of thickness on enteroclysis of ileum
1-1.5 mm
number of ileal folds
2-4 per inch
depth of ileal folds
8 mm
thickness of ileal wall
3 mm
part of small bowel that has numerous lymphoid follicles in submucosa
ileum
what structures greatly expands the absorptive surface of small bowel
valvulae conniventes and villi
CT and MR enterography findings that suggest malignant small bowel lesions include
solitary lesions, nonpedunculated lesions, long-segment lesions, presence of mesenteric fat infiltration and presence of enlarged mesenteric lympn nodes (> 1 cm short axis diameter)
most common neoplasm of the small intesitne, accounting for about 1/3 of all small bowel tumors. they are considered a low-grade malignancy that may recur locally or metastasize to the LN, liver or lung
carcinoid
carcinoid arise from what cell type
endocrine cells (enterochromaffin or Kulchitsky cells)
cells from carcinoid tumor produce
vasoactive substances such as serotonin and bradykinins
carcinoid in SI commonly develops in what part
ileum
only 7% , those with liver metastases, present with carcinoid syndrome (cutaneous flushing, abdominal cramps, diarrhea) because
liver inactivates the vasoactive substances
what substance from carcinoid tumor induces an intense local desmoplastic reaction
serotonin
complications from carcinoid tumor
stricture, obstruction, bowel infarction
imaging signs of fibrosis and metastases in Carcinoid tumor resemble findings from
Crohn disease
barium study shows carcinoid tumor as
luminal narrowing, thickened and spiculated folds, separation of bowel loops by mesenteric mass or bowel loops drawn together by fibrosis and primary lesion appearing as small (< 1.5 cm) mural nodule or intraluminal polyp
CT and MR findings that are highly indicative of carcinoid tumor
sunburst pattern of radiating soft tissue density in the mesenteric fat due to mesenteric fibrosis, bowel wall thickening, primayr lesion appearing as small, lobulated soft tissue mass, occassionally with central calcifications, usually in the distal ileum, marked contrast enhancement of the primary tumor mass and enlarged mesenteric nodes and liver masses due to metastatic disease
SI mass that is half as common as carcinoid
adenocarcinoma
adenocarcinoma of SI is most frequent in what part
duodenum, proximal jejunum
complications of SI adenocarcinoma
bleeding, obstruction, intussusception
infiltrating type of adenocarcinoma produces strictures and are common in
jejunum
polypoid type of adenocarcinoma produces filling defects that are most common in
duodenum
20% of all small bowel malignant tumors
lymphoma
largest immunologic organ in the body, which is the common site for extranodal origin of lymphoma
GI tract
classifcations of lymphoma
mature B-cell neoplasms (mantle cell and Burkitt lymphoma), mature T-cell/natural kille cell neoplasms, Hodgkin lymphoma, posttransplant lymphoproliferative disorder, and histiocytic and dendritic cell neoplasms
most of GI lymphomas are
B-cell type
GI lymphoma usually involves what SI segment
ileum
risk factors for GI lymphoma
infections due to H. pylori, HIV, Epstein-Barr virus, Hep B virus
annular constricting lesions of the small bowel
small bowel adenocarcinoma, annular metastases, intraperitoneal adhesions, malignant GIST, lymphoma
feature of lymphoma due to replacement of the muscularis and destruction of the autonomic plexus by tumor without inducing fibrosis
aneurysmal dilatation
aneurismal dilation of SI in lymphoma is up to what size
> 4cm
sign that refers to sparing of rind of fat surrounding mesenteric vessels that are encased by lymphomatous nodes
sandwich sign
AIDS related lymphoma is of what type
High-grade non-Hodgkin lymphoma
Burkitt lymphoma usually involve what part of SI in children and young adults
ileocecal area
imaging findings in SI Burkitt lymphoma
bulky ileocecal mass
nodular lymphoid hyperplasia is differentiated from lymphona by what characteristics
uniform small size of nodules (2 to 4 mm) and even distribution through the area of involvement
lymphoid hyperplasia that is confined to the terminal ileum and proximal colon is usually considered incidental and may be related to
recent viral infection
diffuse lymphoid hyperplasia is associated with
hypogammaglobulinemia especially low IgA
frequent routes of metastases in SI
peritoneal seeding and hematogeneous spread
peritoneal seeding in SI usually involves the
mesenteric border
hematogeneous spreading on SI usually involves the
antimesenteric border
intraperitoneal implantation on the small bowel serosa is most commonly due to
ovarian carcinoma in women and colon, gastric or pancreatic carcinoma in men
mesenteric border of SI is favored by flow of fluid along the small bowel mesentery from the left upper and right lower abdomen, therefore, implantation is most common along the
terminal ileum, cecum and ascending colon
direct extension in SI occurs in what malignancies
pancreas and colon
GIST tumors that exceed ___ cm tend to ulcerate whether they are benign or malignant
2 cm
malignant GISTs has size of
> 5 cm
adenoma in SI commonly involves the
duodenum and mesenteric small bowel
lipomas in SI is most common in
ileum
rare complication of lipoma in SI
bleeding or intussusception
hemangioma in SI present as
solitary, submucosal, projecting into the lumen as a polyp
hemangioma in SI are located predominantly in
jejunum
autosomal dominant inherited condition consisting of multiple hamartomatous polyps in the SI, colon and stomach associated with melanin freckles on the facial skin, palmar aspects or fingers, toes and mucous membranes
Peutz-Jeghers syndrome
nonneoplastic, abnormal proliferation of all 3 layers of mucosa, epithelium, lamina propria and muscular mucosae
Hamartomatous polyps
hamartomatous polyps are most common in ______, usually pedunculated and are variable in size up to 4 cm
jejunum
involves the small bowel in about half of the case with multiple inflammatory polyps
Cronkhite-canada syndrome
usually involved in Cronkhite-canada syndrome
colon and stomach
ascariasis worms mature where in the small bowel
jejunum
infectious lymphadenopathy is associated with
Yersinia enterocolitica, infections of terminal ileum, TB, HIV and Whipple disease
most common solid mesenteric mass
lymphoma
metastases from this tumors produce a prominent desmoplastic reaction in the mesentery
carcinoid and small bowel adenocarcinoma
benign, locally aggressive, solid, fibrous mesenteric tumor. they ma be solitary or multiple and is associated with Gardner syndrome
mesenteric desmoid
mesenteric desmoid tumors commonly also occur within what muscles
anterior abdominal wall or in the psoas muscles
lymphangiomas that arise in the root of small bowel mesentery. most are thin walled and multiloculated with internal fluid that may be chylous, serous or bloody
mesenteric cysts
congenital, partial, complete replica of the small bowel, most arise from the distal small bowel and may communicate with normal intestinal lumen at one or both ends or not at all. they are lined by intestinal epithelium
GI duplication cyst
malignancies, primarily _____, may arise within duplication cysts
adenocarcinoma
heterogeneous with cystic and solid components
mesenteric teratoma
an uncommon inflammatory condition affecting the root of the mesentery with variable inflammation, fat necrosis and fibrosis
mesenteric panniculitis (sclerosing mesenteritis)
mesenteric panniculitis is associated with other idiopathic inflammatory disorders including
retroperitoneal fibrosis and sclerosing cholangitis
this finding has been termed “misty mesentery” and may be caused by mesenteric infiltration by edema, inflammatory cells, neoplastic cells or fibrosis
mesenteric panniculitis
mesenteric edema may occur with
portal hypertension, cardiac or renal failure or hypoproteinemia
hemorrhage into mesentery can occur with
trauma, ischemia, and anticoagulation therapy
dilation of small bowel lumen means
small bowel obstruction or dysfunction of small bowel muscle
thickening of small bowel folds means
infiltration of submucosa
uniform, regular, straight thickening meanss
infiltration of fluid (edema or blood)
irregular, distorted, nodular thickening means
infiltratrion by cells or nonfluid material
specific diagnosis of small bowel disease requires
matching the small bowel pattern with the clinical data
hemorrhage in small bowel manifest as
thicker folds with scalloping and “thumbprinting” of some folds
nodule size in nodular lymphoid hyperplasia
2-4 mm
nodule size in lymphoma
> 4mm
nodule in size in Whipple disease
1 to 2 mm
nodule size in systemic mastocytosis
< 5 mm
early crohn disease in SI is characterized by
edema and regular folds
more advances crohn disease manifest as
inflammatory cell infiltrate and irregular folds
lymphoma in mesentery manifest as
obstruction in lymphatics and causes edema
lymphoma in small bowel wall causes
nodular, irregular folds
two most commonly encountered small bowel diseases
lymphoma and crohn disease
produces atrophy of the muscularis by the process of progressive collagen deposition resulting in flaccid, atonic often greatly dilated small bowel. excessive contraction of the mesenteric border of small bowel results in formation of mucosal sacculations along the antimesenteric border
scleroderma
part of SI that is severely involved in scleroderma
duodenum and jejunum
“hide-bound” appearance of small bowel is seen in this disease with the appearance of thinned folds tethered together which is produced by contraction of the longitudinal muscle layer to a greater extent thatn the circular muscle layer
scleroderma
diagnosis of scleroderma is confirmed by
skin changes and characteristic involvement of esophagus
presents with malabsorption, steatorrhea and weight loss
adult celiac disease/nontropical sprue
in this disease, the mucosa becomes flattened, and absorptive cells decrease in number, vili disappear. the submucosa, muscularis and serosa remain normal
celiac disease
complications of celiac disease include
small bowel intussusception, lymphoma, ulcerative jejunoileitis, cavitating lymphadenopathy syndrome and pneumatosis intestinalis
classic radiographic findings of celiac disease include
dilated small bowel, normal or thinned folds, a decreased number of folds per inch in jejunum and increased number of folds per inch in the ileum (>5)
CT enterography findings in celiac disease include
reversed jejunoileal fold pattern with loss of folds in the jejunum and increased number of folds in the ileum, small bowel dilation, increased separation of small bowel folds, mesenteric lymphadenopathy, engorgement of mesenteric vessels
it has similar clinical and radiographic findings as nontropical sprue but is confied to india, far east and puerto rico. illness starts with acute diarrhea, fever, malaise, and transitions to chronic steatorrhea, weight loss, malaise, nutrient and vitamin deficiencies
tropical sprue
enzyme required within the absorptive cells of the jejunum to properly digest dissacharides. several population groups, including chinese, arabs, bantu and eskimos may become totally deficient in this enzyme during adult life
lactase
secondary lactase deficiency may develop with
alcoholism, crohn disease and drugs such as neomycin
intestinal ischemia may result from
embolism or thrombosis of the SMA or SMV
CT findings of acute intestinal ischemia
diffuse thickening of bowel wall, usually 8 to 9 mm, rarely exceeding 15 mm, thinning of bowel wall may occur in acute arterial occlusion caused by loss of intestinal muscle tone and tissue volume loss with vessel constriction, bowel edema, intramural hemorrhage, decreased bowel wall enhancement, pneumatosis, adynamic ileus, mesenteric vessels with emboli or thrombi fail to enhance, mesenteric fat stranding and ascites
most radiosensitive organ in the abdomen
ileum
gross dilation of lymphatic vessels in the small bowel mucosa and submucosa. patients present with protein-losing enteropathy, diarrhea, steatorrhea and recurrent infection
lymphangiectasia
refers to lymphatic obstruction due to radiation, CHF or mesenteric node involvement by malignancy or inflammation
secondary lymphangiectasia
pattern of small bowel lymphangiectasia closely resembles what disease
Whipple disease
most common site of GI amyloidosis
small bowel
a myeloproliferative neoplasm characterized by infiltration of mast cells in the skin, bones, lymph nodes, liver and spleen and GI tract
systemic mastocytosis
characteristic skin manifestation of systemic mastocytosis
urticaria pigmentosa
disease that present with arthritis, neurologic symptoms or steatorrhea, generalized lymphadenopathy. demonstration of tiny (1 mm) sand-like nodules spread diffusely over the mucosa or in small groups is strong evidence of the disease. low density or fat density nodes in mesentery are characteristic
Whipple disease
protozoans that may infest the proximal intestine and cause a cholera-like diarrhea with life threatening fluid loss
cryptosporidium and Isospora belli
common systemic infection in AIDS, involving lung, liver, spleen, bone marrow, lymph nodes and intestinal tract
mycobacterium avium intracellulare
common inflammatory disease of uncertain etiology that may involve the GI tract from esophagus to anus
crohn disease
this disease is characterized by erosions, ulcerations, full-thickness bowel wall inflammation, and formation of noncaseating granulomas
crohn disease
patterns of colon involvement in crohn disease include
colon and terminal ileum (55%), small bowel alone (30%), colon alone (15%), and proximal small bowel without terminal ileum (3%)
imaging hallmarks of crohn disease
aphthous erosions, confluent deep ulcerations, thickened distorted folds, fibrosis with thickened walls, contractures and stenosis, involvement of mesentery, asymmetric involvement both longitudinally and around the lumen, skip areas of normal intervening bowel between disease segments
“cobblestone pattern”, which are deep ulcerations that are large and often linear, forming fissures between nodules of elevated edematous mucosa is seen in
crohn disease
abnormal communications between two epithelial-lined organs
fistula
most frequent fistulas in crohn disease
ileocolonic and ileocecal
this infection causes acute enteritis with abdominal pain, fever and often bloody diarrhea taht mimics acute appendicitis or acute Crohn disease. infection is self limited with course of 8 to 12 weeks, most pronounced in the distal 20 cm of ileum
yersinia enterocolitis
clinically and radiographically similar to Yersinia enterocolitis that usually lasts 1 to 2 weeks but relapses are common
Campylobacter fetus jejuni
small vessel vasculitis that affects eyes, joints, skin, central nervous system and intestinal tract. 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
Behcet disease
GITB most commonly involve the
ileocecal area
small bowel diverticula are common in
jejunum along the mesenteric border
megaloblastic anemia due to malabsorption of Vit B12 may be seen in what SI diseases
crohn, diverticula
most common congenital anomaly of the GI tract, present in 2 to 3 % of population. the diverticulum varies from 2 to 8 cm in length, and is located on the antimesenteric border of ileum up to 2 m from ileocecal valce
Meckel diverticulum
tip of Meckel diverticulum may be attached to the umbilicus by a
remnant of the vitelline duct
outpouchings along the antimesenteric border of the small bowel that result from the diseases of the small bowel. they occur most commonly in association with crohn disease or scleroderma
pseudodiverticula or sacculations
