1. Sonographic applications
GI tract

2. Gut signature
Layers of bowel create a characteristic appearance on sonography
Up to 5 layers may be visualized
Uniform and compliant
Sonographic appearance of bowel varies
Depends on its contents
May or may not contain air,gas,feces or fluid within the lumen
Average thickness 3-5mm depending on distension
From the lumen edge to outer wall

3. Measuring thickened wall

4. Doppler evaluation Normal gut : Neoplasia and inflammation :
minimal doppler signal seen
Neoplasia and inflammation :
Increased vascularity
Ischemia and edematous gut:
hypovascular

5. Hyperemia
Valuable supportive evidence
Of inflammatory process

6. Peristalsis Normally seen in small bowel and stomach
Activity may be increased with mechanical obstruction and inflammatory enteritides
Decreased activity is seen with paralytic ileus and in end stages of mechanical obstruction
Hypersecretion,mechanical obstruction and ileus are implicated when gut fluid is excessive

7. Small bowel Mesentery is a fold of peritoneum
Connects small bowel to the spine
Greater omentum lies anteriorly
They become more echogenic and thicker adjacent to a diseased loop of bowel

8. Creeping fat Mesenteric edema and fibrosis
Uniform echogenic halo around gut
Most striking and detectable abnormality on sonography
Detection should lead to a detailed evaluation of regional gut
Thyroid within the abdomen sign-echogenic fat around inflammed bowel

9. Inflammed omental fat

10. Small bowel Valves of Kerckring(valvulae conniventes)
Large folds of mucous membrane
Project into the bowel lumen
Provide greater absorption areas
Slows passage of food

11. Intestinal sizes Small intestine: Large intestine: 6 meters long
Duodenum-25 cm long
Jejunem-2.3 meters long
Ileum-3.5 meters long
Large intestine:
2 meters long

12. Stomach

13. Small intestine

14. Large intestine

15. Lymphadenopathy Enlarged mesenteric and perienteric nodes
Focal hypoechoic masses
Frequently round with loss of linear streak of fat in hilum
Hyperemic-inflammation
Over 3 cm in diameter are suspect

16. Bowel Functions Small bowel Large intestine
Much of the digestion and absorption of food takes place here
Absorption of nutrients and minerals
Large intestine
Absorbs water from remaining indigestible food matter
Passes useless waste material from the body

17. Large bowel haustra Teniae coli Produce haustra
Longitudinal ribbons of smooth muscle on the outside of the colon
Contract lengthwise
Produce haustra
Bulges in the colon
Caused by contractions
of the teniae coli

18. Thickening of the bowel wall
Occurs with:
Infiltration
Inflammation
Edema
Neoplastic invasion

19. Wall thickening con’t Causes include: Pyloric stenosis Hematoma
Intussusception
Tumor
Appendicitis
Edema

20. Neoplasms May demonstrate decreased to intermediate echogenicity
Differential diagnosis of gastric lesions
Adenocarcinoma
Lymphoma
Leukemia
Crohn’s disease
Intussesception
Metastases

21. Neoplasms con’t Most common cancer of colon: Less common:
Adenocarcinoma
Less common:
Leiomyosarcoma
Metastases
lymphomas

22. Intussusception
A proximal bowel segment invaginates into a distal segment
Strangulation of vascular supply occurs
May be caused by malignant lesions in adults
Benign lipomas or polyps may cause this
More commonly seen in children

23. Intassusception

24. Ulceration of bowel Caused by inflammation May also occur with:
Lymphoma
Edema
Neoplasm
Intussusception
Thickened walls create a pseudokidney sign or doughnut sign

25. Meckels diverticulum Normal variant in 2-3% of population
Remnant of prenatal yolk stalk-vitelline duct
Projects from side of the ileum
May cause intussesception in children
5-25cm in length
Attached by a peritoneal fold

26. Appendicitis
Inflammatory process of the appendix that may indent or displace the cecum
Will not exhibit peristalsis
Will not compress
Appendicoliths and periappendiceal abcess may be visualized
Normal appendix is rarely seen except in thin patients or in ascites filled abdomen

27. Appendicitis con’t Graded compression technique:
Used to assess for non-compressible bowel
Use a linear,broad footprint,high frquency transducer-7 mhz
Displace the bowel loops while applying moderate compression
Rebound pain will occur as probe is lifted off the patient fairly quickly
Non-compression and rebound pain are good indicators of inflammation of appendix

28. Appendix -thickened

29. Ileocecal valve

30. Ileocecal valve-inflammed

31. Dilated bowel Occurs when it is obstructed or an ileus is present
Causes paralysis of bowel loops
Peristalsis is absent
Gas accumulates in these loops
Localized ileus may occur near an inflammatory process

32. Obstructed bowel Prevents gas from passing through the GI tract
Builds up proximal to obstructed loop
Portion distal to the obstruction becomes decompressed

33. Plain abdominal x-ray
Bowel obstruction
Air fluid levels

34. Malrotation of the bowel
Can be assessed with doppler
Frequently associated with malposition of SMA and SMV
Varices may be detected
Doppler evaluates blood flow to the bowel wall:
Ischemia
necrosis

35. Esophageal and gastric lesions
Assessed with endoscopy
Varices
Intraluminal tumors
Peptic ulcers
Thickening of all layers occurs
Transrectal endosonography used to evaluate rectum
To identify and stage previously detected cancer

36. Other diagnostic tests
Abdominal x-ray -plain film
Fluid filled loops of bowel
Abnormal gas patterns
Barium swallow(upper GI series)
Fluoroscopic radiologic exam
Contrast material outlines mucosal detail

37. GI series
stomach
Small bowel
follow through
Small bowel

38. Other diagnostic tests con’t
Barium enema
Study of the colon
Contrast material is used
Visualizes the anatomy and mucosa of the large bowel
A tube is inserted in the rectum to administer barium and air

39. Barium filled large bowel

40. Other diagnostic tests con’t
Upper GI endoscopy
Scope must be swallowed by the patient
Used for diagnostic and therapeutic indications
Provides direct visualization
Cytology and biopsy can be performed
Direct visualization of tract

41. Endoscopy

42. Other diagnostic tests con’t
Colonoscopy,Sigmoidoscopy and Anoscopy:
Further evaluates abnormalities seen on a barium enema
Biopsy or lesion removal is possible
Scope is inserted into the anus and moved up the colon to the required level