Flashcards in Small Bowel Deck (92):
DDx for smooth surfaced filling defect in jejunum
Where in the small bowel do lipoma usually occur? What is a key differentiating feature?
Distal in the small bowel
What is the difference between lipoma and liposarcoma?
Lipoma will be homogeneously fat
Liposarcoma will have a soft tissue component
What is the DDx for multiple small bowel lesions on SBFT?
Lymphoma, Polyposis, Hemangioma, Neurofibroma, Metastases
Where do hemangiomas usually occur?
What syndromes have an increased incidence?
Blue rubber nevus
What is CT enterography?
IV contrast enhances the bowel wall
Water attenuation luminal contrast enhances the lumen
How do hemangiomas present on CT?
CAN have calcifications
Small tufts of enhancement within the bowel wall
What two syndromes are associated with diffuse hemangiomatosis
Klipper-trenauny-Weber (varicose veins, cutaneous hemangiomas, soft tissue/bone hypertrophy)
Maffuic (enchondromas, subcutaneous cavernous hemangiomas)
Cauliflower like grouped polyps in the jejunum in a
Peutz Jeughers (Hamartomatous polyps)
What cells do carcinoid tumors arise from? What do they produce? What size does malignant transformation occur? Where are they found in the small bowel?
What is the radiographic appearance?
Kulchitsky cells (APUD), usually 2-3cm
Distal small bowel, within 2 feet of ileocecal valve
Cause a fibrotic reaction leading to kinking of the bowel with obstruction.
Starburst appearance with linear stranding radiating from a central mesenteric mass with calcification indicates what?
Metastatic carcinoid to the small bowel
How do carcinoid mets to the liver present?
Hypervascular mass with central necrosis
Who is at risk of small bowel lymphoma?
Which lymphoma is most common in the small bowel?
What are the 4 classifications of small bowel lymphoma?
Which is most common?
Multiple nodules - most common, can cross IC valve
Polypoid - can be "pseudopedunculated"
DDx for a focal segment of small bowel with smooth mucosa and loss of folds.
Ischemia - will have narrowed lumen
Amyloidosis - may cause fold thickening
Lymphoma - wont have associated fibrosis, thus causing dilation (vs narrowing with ischemia)
Differentiate small bowel lymphoma vs ischemia
Ischemia will cause lumenal narrowing
Differentiate hodgkins vs nonhodgkins in the small bowel
Hodgkins will incite a desmoplastic reaction, causing luminal narrowing
What type of lymphoma in AIDS patients?
What helps to differentiate malignant GIST vs lymphomas?
Where is primary adenocarcinoma most commonly found in the small bowel? What is a known risk factors?
Adult celiac disease
How do malignant GIST spread?
Hematogenous and peritoneal spread
How common is small bowel mets in metastatic melanoma?
50% at autopsy
Bulky intraluminal mass in the retroperitoneal duodenum suggests what?
Invasive renal cell carcinoma
Large cavitated mass devoid of mucosal markings with destruction of the bowel wall can be seen with what 3 entities?
Lymphoma, malignant GIST, colon cancer mets
Where are the 3 most common sites of intraperitoneal seeding? How does it present radiographically?
Pouch of douglas, ileocecal region, superior aspect of sigmoid
Displaced bowel loops with narrowed lumen causing angulation and kinking of loops with fold tethering
Where is the most common location of a duplication cyst?
Biliary gas and mechanical SBO suggests what?
Describe the pathphysiloigy of ascariasis infection
Ingested eggs hatch in the small bowel and penetrate the mucosa
Travel up to lungs by lymphatics/portal system
Travel up bronchi and are swallowed and shed infections eggs
DDx for thin (
What are the 5 questions to ask with an SBO?
1 - is there an SBO
2 - where is the obstruction
3 - What is the cause of the obstruction
4 - Are there complications
5 - How should they be treated
Most common cause of mechanical SBO?
What helps to differentiate paralytic ileus vs obstruction
Gas in the colon distal to obstruction
How does scleroderma present in the small bowel?
"hidebound" - dilation and crowding of straight and thin mucosal folds
sacculations of antimesenteric border, occasional pneumotosis cystoides intestinalis (can be due to steroid use)
Differentiate sprue from scleroderma
Sprue will have hypersecretion and normal peristaltic activity
How does sprue present?
Jejunization of the ileum - adaptive response to loss of absorptive surface in proximal small bowel by villous atrophy
Decrease in number of proximal jejunal folds (
DDx for Thick (>3mm) straight folds
Segmental - ischemia, radiation enteritis, intramural hemorrhage, adjacent inflammation
Diffuse - venous congestion, hypoprotenemia, cirrhosis
What are the causes of bowel ischemia? most common?
arterial hypoperfusion (most frequent)
What is the pathophysiologic timescale of events in bowel ischemia?
What are the 3 possible outcomes?
Submucosal edema and intramural hemorrhage
Radiographic findings of ischemia?
Isolated, rigid dilated and unchanging small bowel loop with thickened mucosal folds
Which portion of GI tract is most susceptible to radiation? At what dose>
What is the pathologic process for radiation? How long before chronic changes?
What are the imaging characteristics?
Endarteritis obliterans. >6 weeks
Fold thickening and serration, nodularity and thumbprinting later on
Stack of coins appearance of the small bowel suggests what?
What associated findings suggest hypoproteinemia as a cause of diffuse fold thickening
DDx for segmental, thick (>3mm) nodular folds
DDx for diffuse, thick (>3mm) nodular folds
Nodular lymphoid hyperplasia
Which segment of small bowel has best prognosis if affected in crohns? Which has highest rate of complication
Distal small bowel
Ileocolic has highest rate of complciation
Localized fold thickening in the proximal small bowel suggests what
Infection (giardiasis, whipple)
Who is prone to giardia infection?
How does giardia present radiographically
Nodular fold thickening, increased secretions, spasm/rapid transit
Malabsorption, arthralgia, lymphadenopathy, abdominal tenderness, increased skin pigmentation
Why is the PAS positive in whipple
glycoprotein deposited in macrophages of the lamina propria
What is a key feature of whipple disease?
Lack of hypersecretion, dilation, or distal bowel involvement
What non GI CT findings helps suggest whipple disease?
low attenuation LN
What is the pathology of lymphangectasia?
What is the usual radiogarphic presentation
Dilated lymph channels in the lamina propria and submucosa of bowel wall with associated enlarged villi
Channels may rupture and spill into lumen causing barium dilution
Thickened folds with nodules
Nodular filling defects
Tx of lymphangectasia?
Medium chain triglycerides
innumerable uniform nodular filling defects throughout small bowel
nodular lymphoid hyperplasia
What is nodular lymphoid hyperplasia usually associated with?
deficiency of IgA or IgM
Usual presentation of nodular lymphoid hyperplasia? Main DDx?
GIve a DDx for terminal ileal discrete ulcerations.
Infection (yersiniosis, amebiasis, TB)
What stones are crohns patients have increased risk of?
Cholesterol gallstones and oxalate renal stones
What is the string sign? Where is it seen most commonly?
Fixed narrowing with short segmental stricture from intramural fibrosis of crohns. Terminal ileum most commonly affected.
Circumferential asymmetry is suggestive of what dx?
Differentiate yersinia/salmonella from crohns of the TI?
Yersinia/salmonella can have superficial erosions and fold thickening WITHOUT strictures
What is creeping fat
Fibrofatty changes in the mesentery adjacent to bowel wall thickening - seen with crohns
How/where does recurrent crohns occur?
Irregular countouring and nodular ulceration of the neoterminal ileum.
Differentiate active vs inactive crohns
Active - soft tissue density or contain a central water density ring
Inactive - Fat within the bowel wall (may be due to corticosteroid use)
DDx for thick small bowel wall with submucosal edema
What helps differentiate intramural vs intraluminal gas
Intraluminal will be nondependent
Intramural will be nondependent and POSTERIOR and DEPENDENT because it is within the wall
name 4 conditions associated with pneumatosis intestinalis
What is a closed-loop obstruction
Mechanical small bowel obstruction in which blood supply to the loop can be compromised
What are the signs of closed loop obstruction
Bowel thickening, vascular engorgement, mesenteric stranding, differential perfusion loop
Small bowel and mesentery encircle the SMA in a whorl pattern in what condition
What is the moulage sign?
"molded" or "casted" structure - resembles a tubular cast with paucity of mucosal folds
seen with Celiac
Featureless ileum with excessive intraluminal fluid obscures with moulage sign
Loss of jejunal fold pattern and flocculation with segmentation of barium
What are the three types of sprue?
Non tropical (gluten sensitive) -- adult and childhood
What are the radiologic features of sprue
Hyper secretion - excess intraluminal fluid
Clumping and segmentation of barium
tubular and featureless jejunum with focal stricture?
Sprue - can develop stricture due to ulcerative jejunoileitis
Name 6 associated conditions with celiac disease
Cavitary lymph node syndrome
Immunoglobulin A deficiency
What part of the GI system does TB affect
Distal small bowel and cecum
What are the findings of GI TB
luminal narrowing with segmental involvement
shrunken and deformed cecum
Prolonged coating of affected bowel segments with barium for several days after the examination
Graft vs host disease
What are the two main regions of rotation of intestine during fetal life
What are the different types of malrotation
Nonrotation - small bowel in right hemiabdomen, colon in left
Incomplete rotation - incorrect location of cecum
Incomplete mesenteric fixation - mobile cecum
What are the 3 main complications of malrotation
Congenital diaphragmatic hernia
What is the consequence of small bowel diverticula
Occasionally lead to bacterial overgrowth
Hyperenhancement of bowel wall, kidneys, and adrenals
Small or collapsed inferior vena cava
What is a meckels diverticulum
Remnant of the omphalomesenteric duct
Which tracer is used in a meckels scan
What organs normally take up TcPertechnetate
Stomach, salivary glands