Ultrasound of the bowel loops and the abdominal lymph nodes

1. Ultrasonography of the Bowel loops
and the abdominal lymph nodes.
Dr/ ABD ALLAH NAZEER. MD.

2. Normal bowl wall anatomy:
The bowl wall consists of 5 layers, of different echogenicity.
Typically, only 2 layers are visible on US, including an inner
hyperechoic layer and outer hypoechoic layer. Normally, bowel
loops are compressible, show minimal vascularity, and have
wall thickness < 2 mm.
Technique:
It is mandatory to check the SMA/SMV relation in every case
Scan is started with a 3.5- to 8-MHz convex probe to provide a
broad overview, to assess the extent of bowel involvement and
to avoid overlooking of extra-intestinal “deeper” associated
findings. Then a high-frequency (4–13 MHz) linear array probe
is used to assess bowel wall thickness and wall layer
discrimination. Specific technique tips and tricks will be
discussed in detail at each pathology.

3. Normal “gut signature” Mucosal interface with lumen (hyperechoic), mucosa (hypoechoic), submucosa
(hyperechoic), muscularis propria(hypoechoic) and serosa (hyperechoic). B: Normal SMA/SMV relationship
in gray scale and color Doppler image.SMA has echogenic rim and seen to the left of the SMV.

4. Normal gastrointestinal tract in ultrasound. A:Normal pylorus. B: Normal
duodenum. C: Normal proximal jejunal loops in LUQ. D:Normal ileal loops
in the right lower quadrant. E: Normal appendix. F: Normal colon (orange
arrows-Haustra).G:Normal distal jejunal loops in the LLQ.

5. Pathologies:
Hypertrophic Pyloric Stenosis (HPS) vs. pyloric spasm:
Ultrasound technique:
The baby is placed in the right oblique position, first the gallbladder
is identified, as the pylorus is usually located slightly medial and
posterior to the gallbladder, then assess the appearance and
measurements of the pylorus. Finally, assess the gastric emptying
through the pylorus and the presence of hyperperistalsis. If the
stomach is empty, the baby is fed with small amount of water.
HPS is common in males (M: F= 4:1), diagnosed in those aged 3-12
weeks. Babies present with projectile non-bilious vomiting, due to
thickened pyloric muscularis propria.
In pyloric spasm, the muscularis propria is either not hypertrophied,
or slightly thick, but < 3 mm thick, with visualized pyloric opening.
Pyloric spasm requires observation while HPS is treated with
surgical pyloromyotomy.

6. 6 week old baby with projectile vomiting for 1 week. Target sign/doughnut sign/ CERVIX sign, with
symmetrical muscular wall thickening of 5 mm, elongated pyloric canal (20 mm) Double internal
layer of crowded mucosa (nipple sign "arrow") Lack of gastric emptying with hyperperistalsis;
typical of hypertrophic pyloric stenosis. B: The pyloric canal is 10 mm long and muscularis propria
is 3 mm in thickness, mild gastric emptying, ongoing with pyloric spasm. C: examination in
the right oblique position, using linear transducer parallel to the right costal margin.

7. Intramural Duodenal hematoma:
Ultrasound technique:
The epigastric region is surveyed with a
linear transducer, duodenal hematoma is
seen lateral or posterior to the pancreatic
head.
It may occur as a result of blunt
abdominal trauma, non-accidental injury to
children. The retroperitoneal attachment and
the lack of a mesentery along with the
proximity of especially the third part to the
spine may account for vulnerability in blunt

8. 2 year old with vomiting and history of trauma 3 days ago. A:a heterogenous, hypoechoic with
irregular cystic areas, well defined lesion in the epigastric region, B: no internal vascularity
demonstrated on color Doppler. CT was done to confirm the diagnosis of duodenal hematoma.
C & D: Axial with (E) coronal enhanced CT images of the upper abdomen, show cystic non
enhancing lesion in the location of the 2nd and 3rd parts of the duodenum (H).

9. Midgut volvulus:
Ultrasound technique:
The position of superior mesenteric artery (SMA) in
relation to superior mesenteric vein (SMV) is recorded in
gray scale and Color Doppler imaging. Whirlpool sign is
looked for and finally the peristalsis, diameter, vascularity
and collapsibility of the rest of the bowel loops is
assessed.
Inverse orientation of the superior mesenteric artery
(SMA) and the superior mesenteric vein (SMV) (i.e. SMV
seen to the left or SMA) is a sign of malrotation.
Whirlpool sign, corresponding to a clockwise wrapping of
the SMV around the SMA, has a high predicting value and
is an imaging characteristic of midgut volvulus.

10. 7-month-old boy. abnormal SMA/SMV correlation was seen, Color Doppler ultrasound
in the epigastric region show whirling vessels and was diagnosed with mid gut volvulus.

11. Incarcerated/ Strangulated inguinal hernia:
Ultrasound technique:
Both inguinal regions along with scrotum are
examined with linear transducer, presence of
bowel peristalsis, wall thickness and vascularity
are recorded.
The bowel, ovaries, or fallopian tubes are the
organs that most commonly incarcerate into the
inguinal region, through a patent processus
vaginalis, which may progress rapidly to
strangulation (vascular compromise and
infarction) of the incarcerated contents. (Fig.6)

12. An 8 month old boy with scrotal swelling and abdominal distension. Longitudinal
images through the inguinal region, show dilated, thick hyperechoic walled, fluid
filled, aperistaltic small bowel loop seen superior to the testis (*) with preserved
vascularity. Findings are consistent with incarcerated inguino-scrotal hernia.

13. Henoch Schönlein Purpura
HSP is a small-vessel, immune-mediated
vasculitis associated with
immunoglobulin
A (IgA) deposition. Peak incidence 3-10
years. Gastrointestinal symptoms are
encountered in 70% of the cases. Seen
as multifocal bowel thickening, vascular
engorgement and intussusception,
typically ileoileal type.

14. 8 year old boy, known case of Henoch Schonlein Purpura, (1)long segment of thickened ileal
bowel loop in the right lumbar region, (2) in the right iliac fossa and (3) a short segment of
thickened jejunal loop in the left upper quadrant, with normal peristalsis. All thickened bowel
loops are fluid filled,loss of normal stratification, due to intramural hemorrhage.

15. Crohn’s disease:
Crohn's disease may present with acute,
appendicitis-like symptoms. US may play
an important role in establishing the initial
diagnosis, assessing the extent of bowel
involvement and diagnosing possible
complications.
The sensitivity of US for detecting ileocecal
Crohn's disease of over 95%.

16. Axial US images of a 12 year old girl, a known case of crohn’s disease in remission. (A):
Hypoechoic thickened terminal ileal wall with total loss of stratification, fatty aggregation
(B) mild hypervascularization at color-Doppler. (C)Thickened colon in the right lumbar
region. (D&E) follow up study done 6 months post treatment, shows mild ileal and colonic
thickening with preserved stratification and significant regression of fatty aggregation.

17. 14year old boy, with abdominal pain and vomiting. Irregularly thickened long segment of ilium
extends from RIF (A) till the supra-pubic region (B&C) with loss of normal stratification and
significant surrounding fatty aggregation (*) a sign of longstanding Crohn’s disease. Axial
balanced FFE (D) and post contrast T1 MR images of the correspond to the US findings

18. 14 year old boy, known case of Crohn’s disease, (A) axial enhanced CT image of the lower
abdomen show thickened segments of ileal bowel loops and ascending colon, mucosal
enhancement, surrounding free fluid and fat stranding in going with active Crohn’s disease.
He presented with vomiting and high inflammatory markers 6 months after initial diagnosis
(C) US of the pelvis shows a large collection with multiple air foci, confirmed by CT (D & E).

19. Idiopathic Ileocolic vs. Eneteroenteric Intussusception:
Ultrasound Technique:
Bowel is screened with five to six vertically oriented, overlapping
lanes 'mowing the lawn technique' using a linear high frequency
probe.
Intussusception occurs when a proximal bowel loop invaginate into
an adjacent distal bowel loop, typically within the ileocecal region,
90% of the time without a lead point, rather due to hypertrophy of
Peyer’s patches. Predominantly seen in children 3 months to 3 years
of age. When it occurs outside of the typical age range, it is likely to
be associated with a pathologic lead point (Meckel’s diverticulum,
duplication cyst, polyps, non-Hodgkin’s lymphoma).
Small bowel intussusception is transitory, usually seen in the side of
the abdomen during scanning. It contains less mesenteric fat and
lymph nodes, with a small outer diameter (less than 2.5 cm), short
segmental invagination (less than 3 cm), and peristaltic wall motion.

20. Baby girl, with vomiting and colic. (A) Concentric parallel rings of bowel wall ”Target/ doughnut
or pseudokidney sign” ,in the RUQ, its diameter >2.5 cm, ongoing with ileocolic intussusception.
(B) Color Doppler: preserved vascularity. (C) longitudinal view: long segment of invagination
(opposed to short segments seen in enteroenteric intussusception. (D) Another case with ileocecal
intussusception, notice layering of fluid between the telescoped bowel loops and mesenteric
lymph nodes, when seen reflects decreased probability of reducability. (E) A case of entero-enteric
intussusception seen in the LUQ, its diameter <2.5 cm. Self limited, needs no reduction.

21. Acute Appendicitis:
Ultrasound Technique:
Graded-compression is applied with the linear
transducer at the point of maximal tenderness.
If no abnormality is seen, a thorough search for
direct or indirect signs of appendicitis in the right
iliac fossa, right lumbar and subhepatic regions is
sought[6] in supine and left oblique positions.
Most commonly occurs in school agers. Diagnosis
can be challenging as inflammatory markers are
not elevated in 20% of cases and clinical
presentation is variable or atypical in 30-45%
of cases, especially in the preschool agers.

22. Atypical locations of the appendix.

23. Direct and secondary signs of acute appendicitis as reported by
Gerhard Mostbeck et al, ‘’ How to diagnose acute appendicitis:

24. 7 months baby, with vomiting and bloody diarrhea, a case of phlegmonous acute appendicitis.
US of the right hypochondrial region show thickened non compressible appendix, with preserved
stratification, omental fatty aggregation (*) and an overlying dilated hyperechoic small bowel loop
(B). B: 8 year old, a case of gangrenous acute appendicitis. The appendix shows interruption
of the mucosal continuity (->),hypervascularity and periappendiceal fatty prominence (*).

25. A 2 year old boy, with abdominal pain for 3 days and vomiting. Acute gangrenous tip
appendicitis with interrupted mucosa (->), appendicolith (A) and fatty aggregation
superior to the inflamed tip, peri-ileal (*) The normal proximal appendix (N)

26. (A): A 4 year old, x-ray shows dilated small bowel loops. US shows fluid filled dilated
bowel loops in the LLQ with hyperechoic thickened wall and hypoperistalsis. RIF has ill-
defined hypoechoic fluid (F) and omental fat (*) prominence, suggestive of perforated
appendix. (B) Another case of perforated appendicitis, characterized by disruption
of the entire thickness of the appendicular wall with periappendiceal free fluid.

27. 4 different cases of appendicular abscesses (A&B) are subhepatic,(C,D&E) are
pelvic, showing varying echogenicities, ranging from cystic with internal debris
(A), hypoechoic (B), heterogenous predominantly hypoechoic (C), heterogenous
with predominant cystic component (D) or heterogenous with an appendicolith.

28. Algorithm for acute appendicitis diagnosis.

29. Acute gastroenteritis
Symptom-wise, the commonest mimicker of
acute appendicitis. the most common causes
of gastroenteritis in children are viruses
(rotaviruses, adenoviruses, enteroviruses),
bacteria (food poisoning, pathogens like
Salmonella, E. Coli, Listeria), and intestinal
parasites (like amoeba histolytica & Giardia
lamblia).

30. A 3-year-old girl, with vomiting and bloody diarrhea. Thickened
sigmoid colon seen with predominant submucosal layer thickening.
(B & C)diffusely thickened colon in the RIF/LIF, with loss of Normal
bowel stratification. Small bowel loops were not thickened.

31. TUS in Celiac Disease
Despite the fact, that gold standard for the diagnosis of celiac disease is
histologic confirmation of the intestinal damage in serologically positive
individuals, in patients with untreated celiac disease we can regularly find
out several sonographic signs that raise suspicion of this chronic disease
also in clinically asymptomatic persons. Increased fluid content in
moderately dilated bowel loops (25 to 35 mm) with hyperperistalsis in
fasting state, lightly thickened bowel wall (3–5 mm) and thickened
valvulae conniventes are most frequently seen in patients with untreated
celiac sprue. Reduced number of jejunal folds and increase of ileal folds
(jejunalization of ileum) intermittent intussusceptions due to
hyperperistalsis, presence of slightly enlarged mesenterial lymph nodes
(5–10 mm in short axis)and dilatation of SMA with low resistive index are
also very frequent. In comparison to controls, celiac patients had higher
superior mesenteric artery blood velocity and flow, with lower resistance
indexes and higher portal vein velocity and flow in comparison to
controls. Presence of small amount of free peritoneal fluid and increased
gallbladder volume are also seen in these patients.

32. Celiac sprue: (a) Dilated loops of small bowel with thickened wall, and valvulae conniventes hyperperistalsis—
standard abdominal probe. (b) Intussusception of jejunum in transverse (left) and longitudinal section in celiac
sprue—high resolution probe. (c) Dilated SMA (9 mm) in a patient with untreated celiac disease—standard
probe. (d) Low resistive index-RI (0.69) in SMA in untreated celiac disease—standard probe.

33. Acute pancreatitis:
It is rare in children, occurs in all age
groups. Diffuse or focal enlargement of
the pancreas is attributable to edema;
however, pancreatic enlargement has
been reported to be absent on
ultrasound in approximately 50% of the
patients.

34. A 30 month old girl, with vomiting. Ultrasound showed (A) hyperechoic pancreatic
parenchyma (B) Bulky pancreatic head (H) with fluid in the lesser sac (open arrow),
C: Rim of hypoechoic peri-pancreatic fluid (arrow) and heterogeneous body - tail
junction (*) D: companion case of normal pancreas, iso-echoic to the liver.

35. Etiology of acute pancreatitis in children

36. Focal acute bacterial nephritis:
It is due to a localized non-
liquefactive inflammatory renal
bacterial infection and considered
to be a midpoint in the spectrum
ranging from uncomplicated
pyelonephritis to intrarenal
abscess.

37. 8 year old boy, with fever and vomiting. (A) A geographic area of hypoechogenicity in the
upper pole of the right kidney (*), (B) Color Doppler image shows patent renal vein and
segmental renal arteries, (C ) Power Doppler image shows focal hypoperfusion of the
upper polar renal parenchyma (*), (D) Coronal enhanced CT image shows right upper
polar wedge shaped enhancement defect (arrow) no abscess formation.

38. Ovarian torsion:
Complete or partial torsion of ovary on its
pedicle vascular supply due to long &
flexible mesoovary. It accounts for
approximately 3% of all cases of children
with acute abdominal pain. More common
in adolescents after menarche. The presence
of vomiting, short duration of abdominal
pain, and elevated CRP level (>5 mg/L) have
a predictive value for the diagnosis of OT.

40. A 13 year old female, with acute ovarian torsion. The right ovary is in the
mid-line, enlarged, measures 4.5 cm in largest diameter, with a volume of
33 ml, compared to left ovary which was 10 ml (not shown). Multiple
peripheral small follicles seen. Lack of arterial and venous blood flow.

41. TUS in Detection of Small Bowel Tumors
The most frequently visualized tumors of SB are localized in duodenum and
terminal ileum. Tumors in other parts of SB can be viewed after gaining
significant volume and are causing clinical symptomatology. Among the
malignant tumors are more frequent adenocarcinoma localized prevalently
in duodenum, then Carcinoid with prevalent localization in terminal ileum,
followed by lymphomas in ileum and jejunum, and less frequent
mesenchymal tumors, predominantly in jejunum. Most of the
adenocarcinoma occurred in the duodenum and their relative frequency
decreased in aboral direction: 29.9% in the jejunum and 16.0% in the ileum.
The carcinoids showed an opposite trend, an increasing relative frequency in
aboral direction: 3.9% in the duodenum, 9.2% in the jejunum and 86.7% in
the ileum. Lymphomas were more frequent in the ileum (49.5%) compared to
jejunum (29.4%) and duodenum (21.0%). Most sarcomas occurred along the
jejunum (46.7%). Carcinoid tumors are oval hypoechogenic vascularised
lesions and , lymphomas circularly affecting bowel segment with stenosis
and dilatations of lumen. Most of gastro-intestinal lymphomas cause
circumferential involvement of the bowel wall. Metastatic tumors of SB
as well as benign tumors are sporadically visualized by TUS due to
intussusception caused by these tumors.

42. Tumors of small bowel. (a) Solid oval tumor in the lumen of terminal ileum with hypervascularization in CFD
(a) High resolution probe. (b) Oval solid tumor in D2 segment of duodenum—Standard abdominal probe. (e)
Longitudinal section of thickened small bowel loop (S) with stenosis and dilatation (D) of lumen. Standard
abdominal probe. (f)Transversal view with high resolution probe in dilated segment shows hypervascularization
of thickened wall (f). Surgery confirmed suspected T-lymphoma of jejunum in untreated celiac disease.

43. Conventional ultrasound (US) is the recommended imaging method
for lymph node (LN) diseases with the advantages of high
resolution, real time evaluation and relative low costs. Current
indications of transcutaneous ultrasound and endoscopic
ultrasound include the detection and characterization of lymph
nodes and the guidance for LN biopsy. Recent advances in US
technology, such as contrast enhanced ultrasound (CEUS), contrast
enhanced endoscopic ultrasound (CE-EUS), and real time
elastography show potential to improve the accuracy of US for the
differential diagnosis of benign and malignant lymph nodes. In
addition, CEUS and CE-EUS have been also used for the guidance
of fine needle aspiration and assessment of treatment response.
Complementary to size criteria, CEUS could also be used to evaluate
response of tumor angiogenesis to antiangiogenic therapies. In this
paper we review current literature regarding evaluation of
lymphadenopathy by new and innovative US techniques.
Lymph node.

44. Homogeneous hyperenhancement(Lymphoma). Left
figure: the CEUS mode, the red circle: lymph node; Right
figure: the comparative gray-scale ultrasonography.

45. Inhomogeneous hyperenhancement(Metastasis). Left
figure: the CEUS mode, the red circle: lymph node; Right
figure: the comparative gray-scale ultrasonography.

46. Circle enhancement (Tuberculosis). Left figure: the CEUS mode, the red
circle: lymph node, the yellow circle: surrounding tissue, the blue circle:
artery; Right figure: the comparative gray-scale ultrasonography.

47. Isoenhancement (Reactive lymphadenopathy). Left figure: the
CEUS mode, the red circle: lymph node; Right figure: the
comparative gray-scale ultrasonography.

48. Non-Hodgkin’s lymphoma
involving the inguinal
region. A: Sonoelastography
reliability test evaluation
reveals typically asymmetric
and circumscribed
infiltrated harder (blue)
lymph node tissue in low
grade follicular cell
lymphoma; B: Elastography
(acoustic structured
quantification) reveals
mainly homogenous diffuse
infiltration in high grade
follicular cell lymphoma.

49. Colorectal carcinoma
with presacral
circumscribed lymph
node metastasis
proven by colonic
endoscopic ultrasound
using Fine Needle
Aspiration Cytology.
Sonoelastography
reliability test
evaluation reveals
typically harder (blue)
area in the lymph
node.

50. Thank You.