Diagnostic ultrasound ( PDFDrive )

1840 PART V Pediatric Sonography
A
B
FIG. 53.11 Gastric Diaphragm. (A) Note the thin membrane (arrows) crossing the luid-illed gastric antrum. (B) The same diaphragm seen
during a contrast upper gastrointestinal series (arrows).
seen with other conditions, such as eosinophilic gastritis,
inlammatory pseudotumor, 31 chronic granulomatous disease,
Ménétrier disease, 32 milk allergy, and prostaglandin-induced
antral foveolar hyperplasia. 33,34 he last condition is self-limiting
and can be seen in asymptomatic infants. 35
FIG. 53.12 Gastritis. Marked thickening of the gastric mucosa
(arrows) is visible in this immunosuppressed transplant patient.
of deinition of the individual layers of the gastric wall (Fig.
53.12). he ulcer crater itself usually is not visualized sonographically.
Ultrasound can also be used to follow therapy, showing a
return of the normal gastric wall layers as the ulcer heals. hickening
of the gastric mucosa is not a speciic inding and can be
Bezoar
Lactobezoars are the most common form of bezoar in children,
occurring predominantly in infants who are fed improperly
reconstituted powdered formula. In older children, trichobezoars,
caused by the ingestion of hair, are more common. Both types
of bezoar can be easily identiied with ultrasound, especially if
the patient is given clear luid to help outline the mass. Lactobezoars
appear as a solid, heterogeneous, echogenic intraluminal
mass 36 (Fig. 53.13). With trichobezoars, air tends to be trapped
in and around the hair ibers, which causes a characteristic arc
of echogenicity that obscures the mass but conforms to the shape
of the distended stomach. Distending the stomach with water
and scanning in decubitus and upright positions allows the bezoar
to be separated from the gastric wall, clinching the diagnosis 37
(Fig. 53.14). Trichobezoars can rarely lead to small bowel obstruction
in cases where the bezoar extends beyond the stomach,
called Rapunzel syndrome when extending through a large
portion of the small intestine. 38
In the case of small bowel obstruction, a bezoar proximal to
the obstruction has a twinkling artifact, a characteristic arclike
shadow with strong posterior acoustic shadowing, whereas fecal
material has neither the posterior shadowing nor the twinkling
artifact. Bezoars can be diicult to diferentiate from fecal material
proximal to a small bowel obstruction by computed tomography
(CT). 39