Resident presentation

1. Yasser Asiri , R2

3. Longitudinal ultrasound shows an enlarged mesenteric lymph node (white solid arrow) acting as a lead point for an intussusception. From outer to inner there is the
intussuscipiens (black open arrow), returning limb (white open arrow), mesentery (white curved arrow), entering limb of intussusceptum (black solid arrow).

4. Transverse transabdominal ultrasound shows thickening of the pyloric muscle (caliper #2) of 5 mm and elongation of the pyloric channel (caliper #1) of 22 mm in
this patient with HPS. Notice the close proximity of the gallbladder (white solid arrow).

5. Appendicitis, intussusception, and hypertrophic pyloric stenosis
(HPS) are three of the most common reasons for emergent
abdominal imaging in pediatric patients.
Children are particularly at risk for adverse effect of ionizing
radiation and although low dose radiation is associated with
small but significant increase in life time risk of fatal cancer.
The use of MRI is Impractical.

6. US doesn’t involve ionizing radiation , relatively
inexpensive , widely avilable, and doesn’t require
sedation. But most of all, it allows for dynamic
assessment of bowel peristalsis and compressibility.
Therefore , the ability to diagnose or exclude diseases
with US should be part of a core radiology skills set
for any practice that include a pediatric population.

7. Appendicitis
 Appendicitis occurs in all age groups but has a higher
incidense in children between 5-15 years of age.
 It is generally understood that it’s a result of obstruction of the
appendiceal lumen.
 Obstructed lumen becomes distended. => pressure across it’s
wall increase =>subsequent decrease in mural perfusion occur.
And because the appendix has only arterial supply, any
decrease in mural perfusion may result in gangrene and
perforation quickly.

8. it’s been estimated that the prevalence of
ruptured appendicitis in children ranges
between: 30%-70% of cases. This may be
explained by:
Younger children cannot describe their
symptoms.
One third have atypical clinical findings.

9. the sensitivity and specficity for US alone in
diagnosis of appendicitis in children were
88% and 94% . These can be achieved by
focused re-imaging by the radiologist
following the US tech examination to make
sure that alternative diagnosis is not
overlooked.

10.  Most accurate US findings for acute appencitis is
an outer wall diameter greater than 6 mm under
compression “posivite and negative predicitve
value of 98%”.
 Other less sensitve and specific findings include:
1. hyperemia on color doppler.
2. Echogenic inflammed periappendicieal fat.
3. Visualization of the appendicolith.

11. Pitfalls
 Operator dependant! Therefore every radiology
resident should be taught how to perform
appendeacal US and achieve and maintain
competence.
 Other limitations of US may include:
1. Patient obesity.
2. Sever tenderness which prevent adequate
compression.
3. If perforation has occurred , the appendix may not
be recognized as a discrete structure.

14. Transverse color Doppler ultrasound shows increased vascularity in the appendiceal wall (white solid arrow) and mesoappendix (white open arrow). The absence of
wall vascularity should raise the concern of gangrene.

15. Transverse ultrasound shows markedly distended appendix (white open arrow) containing echogenic material and an area of acoustic shadowing related to an
appendicolith (white solid arrow).

16. Longitudinal color Doppler ultrasound in a 10 year old with right lower quadrant pain shows a dilated, blind-ending tubular structure with very hyperemic wall
(black open arrow). There is increased echogenicity of the periappendiceal fat. The findings are consistent with acute appendicitis.

17. Longitudinal ultrasound image shows a dilated, blind-ending structure with thick wall (white open arrow) and internal shadowing echogenic foci (white solid arrow),
consistent with appendicitis and appendicoliths.

18. Mimics
 Mesientric addenitis. 2nd
most common cause of RLQ
pain. Dx of exclusion, usually self-limiting and
requires no surgical intervention.
 Infectious: terminal ilitis or ileocecitis: Yersenia ,
Salmonella, Campylobacter infections.
 Chron’s Disease : one/third of patients initially
presents with symptoms mimicking appendicitis.

19. Non-surgical mimincs

20. Intussusception
 Usually occurs in children between 6
months and 2 years.
 The “classic” clinical presentations consist
of:
1. Acute colicky abd. pain.
2. Current jelly or frankly bloody stool.
3. Palpable abdominal mass.
4. Vomiting.

21.  US is a highly sensitive and specific test for intussusception.
 Easily identifiable even by inexperinced users and non-
pediatric radiologist.
 In recent study in which large proportion of examination were
interpreted by radiology residents and general radiologists
during oncalls and weekend shifts , US had sensitivity of 97.9%
and specificty of 97.8% and a negative predictive value of
99.7% for intussusception.
 Reimaging the patient after US technologist’s examination is
advised to increase diagnostic confidence.

22.  Target or donut sign.
 Pseudokidney sign.
 The intussception contains multiple limps of
bowel and the attached mesentry as well as
the lymph nodes which will create a mass
measures up to 4-5 cm.

23. Transverse ultrasound shows an ileocolic intussusception. The intussusceptum (white open arrow) with a "target" appearance is visible medial to the right kidney
#SP#(white curved arrow).

24. Longitudinal ultrasound shows an enlarged mesenteric lymph node (white solid arrow) acting as a lead point for an intussusception. From outer to inner there is the
intussuscipiens (black open arrow), returning limb (white open arrow), mesentery (white curved arrow), entering limb of intussusceptum (black solid arrow).

25. Longitudinal transabdominal ultrasound shows multilayered appearance of intussusception (white open arrow) giving rise to "pseudokidney" sign. Note minimal
fluid trapped between layers (white curved arrow).

26. Longitudinal color Doppler ultrasound of intussusception shows central leash of mesenteric vessels (white curved arrow) that are pulled along with intussusceptum
(white solid arrow) into outer intussuscipiens (white open arrow). Presence of vascularity predicts reducibility.

27. Transverse color Doppler ultrasound shows mural vascularity (white curved arrow) in central intussusceptum (white open arrow). Note minimal fluid around the
intussusception (white solid arrow).

28. Transverse transabdominal ultrasound shows classical "target" or "doughnut" sign of intestinal intussusception (white open arrow). Note ring in ring appearance
formed by different layers (white solid arrow) of intestine & central lymph node (white curved arrow) acting as lead point.

29. Hypertrophic Pyloric Stenosis
 95% of cases are seen between 3rd
and 12th
week of life.
 HPS was associated with very high mortality
rate, rate has dropped to 2% with surgical
treatment.
 Nonbilious vomiting is the main presenting
symptoms.

30.  If diagnosis was delayed , dehydration ,
electrolyte imbalance , or weight loss can
result.
 US is accepted as the first line option.
 Highly accurate, with specificity and
sensitivity approaching 100% in experienced
hands.

31.  Persistent abnormal thickening of the pyloric muscle is the most
important parameter to establish the diagnosis of HPS.
 The apperance of HPS in long-axis US images has been termed the
“Cervix” sign. Due to its resemblence to the uterine cervix.
 The threshold value of the pyloric thickness for diagnosis of HPS is
generally greater than 3.5mm.
 An abnormal lenghth typically measures from about 14mm-20mm.
 The actual numeric value is less important than the overall
MORPHOLOGY of the canal and the real time observations.

32. Pitfalls
 Gastric overdtisention, which displaces the
antrum and pylorus posteriorly may leads to
false negative result.  gastric
decompression with entric tube can be an
effective method to optimaize the exam.
 Changing the patient’s position.

33. Ultrasound shows a normal pylorus between open arrows (white open arrow) with anechoic fluid in gastric antrum and in distended duodenal bulb (white curved
arrow).

34. Ultrasound shows cursors measuring single wall thickness of the pyloric muscle and formula mixed with air distending the stomach (white curved arrow). On most
ultrasound exams, the pylorus is located close to the gallbladder (white open arrow), but if the stomach is very full, it may be displaced into the right lower
quadrant.

35. Ultrasound in the same baby with HPS shows cursors measuring the pyloric channel length. Notice the echogenic mucosa within the pyloric channel, which also
hypertrophies and contributes to obstruction.

36. Ultrasound shows cursors measuring the length of the pyloric channel in a baby with HPS. In this infant, enough fluid leaves the stomach to distend the duodenal
bulb (white solid arrow), which is a useful landmark. Antral wall thickening seen in antritis should not be confused with pyloric stenosis if the duodenal bulb is
identified.

37. Ultrasound scan at 90° to the pyloric channel shows the "donut" sign of HPS: Thickened hypoechoic muscle (between cursors) and redundant echogenic mucosal
lining.

38. Transverse transabdominal ultrasound shows thickening of the hypoechoic pyloric muscle (calipers), measuring 5 mm in this patient with HPS.

39. Transverse transabdominal ultrasound shows thickening of the pyloric muscle (caliper #2) of 5 mm and elongation of the pyloric channel (caliper #1) of 22 mm in
this patient with HPS. Notice the close proximity of the gallbladder (white solid arrow).

40. Transverse ultrasound shows a cross-sectional view of the thickened pyloric channel; diameter is measured between cursors #1 and single wall thickness measured
with cursor #2.

41. Pitfall
 If the exam was done quickly, Transient
pylorospasm can mimic HPS.
 In transient pylorospasm, the muscle
thickness usually doesn’t exceed 3mm.
 At observation, the pylorus relaxes with
corresponding change in shape.

42. Ultrasound shows pylorospasm which can mimic HPS, but typically does not meet measurement criteria and usually resolves with time and glucose water feeding.
Channel length is marked by cursors.

43.  In patient with persistent unexplained
vomiting, upper GI series may be performed
to evaluate for hiatal hernia , antral web, or
duodenal obstruction.

44. Conclusion
 US is an important tool in the evaluation of
pediatric abdominal conditions such as
addendicitis, intusscesption , and HPS.
 Assessment with these conditions should be
part of a core radiolgy skills set for any
practice that include a pediatric population.

45. Thank you