The document describes the normal ultrasound appearance and technique for scanning the gastrointestinal tract. Key areas that can be visualized include the gastroesophageal junction, gastric antrum, duodenum, ileocecal region, ascending and descending colon, rectum, and lower sigmoid colon. The normal wall layers of the bowel are described as well as measurements for bowel diameter and wall thickness in different regions. Dynamic assessment of peristalsis and compressibility are also discussed.

3. HOSSAM MOUSSA SAKR

4. Technique & normal
appearance of GIT US

6.  Start with a systemic survey using a
curvilinear probe to get an overview over the
different parts of the gastrointestinal tract.
 Proceed with a high-frequency linear probe
to obtain details and focus on the actual
problem.

7.  It is possible to scan the distal esophagus & GEJ by
tilting the probe cranially in the epigastrium.
 The stomach is scanned in longitudinal and
transverse sections via a sub xiphoidal approach from
the cardia to the pylorus using the left lobe of the
liver as acoustic window
 The fundus of the stomach can be demonstrated in a
translienal view (through the spleen).

8. Abdominal esophagus in TS & LS views

9. Gastric antrum, pyloric canal & first part of duodenum

10.  The muscular layer of the stomach, especially
that of the antrum, is more pronounced than
in other parts of the intestine.
 In a non-distended condition the mucosal folds
of the gastric corpus and fundus are well
demonstrable

11. Gastric mucosal folds

12.  The duodenum is identified by its “C-shaped”
course around the pancreatic head.
 The first part of the duodenum is seen just
distal to the pylorus.
 The third part of the duodenum lies between
the aorta and the superior mesenteric vessels

13. Duodenum 2nd & 3rd parts
Gall bladder
2nd part duodenum
Liver
Pancreas
3rd part duodenum
SMV
SMA

14.  The jejunum is usually located in the left
upper and mid abdomen and the ileum in the
right mid and lower abdomen.
 The right iliac vessels are a landmark of the
ileocecal region

15.  The valvulae conniventes are typical of the
small intestine.
 They decrease in number and height from the
proximal jejunum to the distal ileum.
 They are best visible when bowel loops are
fluid filled

16. Intestinal valvulae conniventes

17.  The colon is characterized by its haustration
which using US is best visible at the ascending
and transverse colon.
 The left hemicolon is seen more often in a
contracted condition

18. Colonic haustrations

19.  Beginning at the right anterior superior iliac
spine and moving medially to the edge of the
rectus muscles in a sagittal plane, the right
common iliac vessels are identified.

20.  Rotating anticlockwise to a transverse plane
and moving cranially, the first bowel loop
crossing from medial to lateral is identified as
the terminal ileum.

21.  This is followed to the ileocaecal valve and
caecum.
 The base of the appendix can be identified at
the deep margin of the caecum where the three
taenia coli meet

22. RT ASIS
RT RA
MUSCLE
RT ILIAC VS

23. RT RA
MUSCLE
RT ILIAC VS

24. RT RA MUSCLE
RT ILIAC VS
TERMINAL ILEUM

25. ILEO-CECAL JUNCTION

26. APPENDIX

27. Appendicular
compressibility

28.  The ascending colon is followed up towards
the hepatic flexure.
 The rest of the colon can be followed via the
transverse segment distally towards the
rectum.

29.  Intercostal imaging may be required to
visualize the splenic flexure.
 Elevating the left arm and rotating to a partial
right decubitus position with straight left leg
can improve image acquisition

30.  Beginning at the left anterior superior iliac
crest and moving medially to the edge of the
rectus muscles in a sagittal plane, the left
common iliac vessels are identified.

31.  Rotating clockwise to a transverse plane and
moving cranially, the first bowel loop crossing
from medial to lateral is identified as the
sigmoid colon.
 The rectum is visualized through the filled
bladder

32. LT ASIS
LT ILIAC VS
LT RA
MUSCLE

33. LT RA
MUSCLE
LT ILIAC VS

34. LT RA
MUSCLE
LT ILIAC VS
SIGMOID
COLON

35. Sigmoid colon

36. Rectum

37.  The GEJ
 The Gastric antrum
 The Duodenum
 The Ileocecal region.
 The Ascending and Descending colon

38.  The Rectum
 The Lower sigmoid colon
 The Left colonic flexure

39. A. Bowel wall
B. Bowel lumen
C. Dynamic examination
D. Associated findings

40. 1. Wall thickness
2. Echogenicity & Stratification
3. Vascularization

41. 1. Luminal width
2. Contents within the lumen

42. 1. Length of affected segment
2. Compressibility.
3. Peristalsis

43. 1. Peritoneal fluid
2. Mesenteric lymph nodes
3. Others: e.g. liver, spleen, …..

44.  Wall thickness of the alimentary tract differs
from part to part and depends largely on the
state of distension or contraction.
 Under normal conditions stomach thickness
measures from mm, small bowel from
mm, and the colon from mm.

45. 1. Inner hyperechoic layer: superficial mucosal
interface
2. Inner hypoechoic layer: mucosa
3. Middle hyperechoic layer: submucosa
4. Outer hypoechoic layer: muscularis propria
5. Outer hyperechoic layer: serosa and interface
to the serosa

46. 1 2
3
5
4
1. superficial mucosal interface
2. Mucosa
3. Sub mucosa
4. Muscularis propria
5. serosa

47.  Small bowel diameter beyond 25 mm should
be regarded as abnormal particularly when
motility is reduced.
 Small bowel diameter less than 10 mm should
also be regarded as abnormal

48.  Normal colonic caliber ranges from cm,
with the largest diameter in the cecum
 The remainder of the colon is dilated when it is
greater than cm
 The cecum is considered dilated if larger than
cm in diameter