Diagnostic ultrasound ( PDFDrive )

1834 PART V Pediatric Sonography
A
B
FIG. 53.1 Gastroesophageal Relux. (A) Normal contracted gastroesophageal junction (arrow). (B) Later, the lower esophageal sphincter
opens, and relux of luid and formula into the esophagus is visible (arrow).
Stomach: Optimal Measurements
Normal pyloric muscle thickness ≤2 mm
Normal gastric mucosa thickness ≤2-3 mm
Peristalsis through pylorus
Esophagus
Most of the esophagus is inaccessible by sonography because of
surrounding aerated lung. Only the subdiaphragmatic portion
of the esophagus is usually visible (Fig. 53.1A). he gastroesophageal
junction can be seen by examining the patient with sagittal
images in the supine or right-side-down decubitus position. 1-3
his technique permits observation of the function of the gastroesophageal
junction and can be used to detect gastroesophageal
relux. Relux is noted when luid is regurgitated into the retrocardiac
portion of the esophagus (Fig. 53.1B). Color Doppler
sonography may facilitate the detection of gastroesophageal
relux. 4 Hiatal hernias can also be detected with sonography,
which may be more sensitive than barium studies for detecting
small degrees of herniation 5,6 (Fig. 53.2). However, the sonographic
techniques required are operator dependent and have not gained
much popularity. herefore esophageal abnormalities are usually
assessed with other imaging modalities, such as luoroscopy or
endoscopy.
Stomach
Most abnormalities of the stomach in infants and children involve
the gastric antrum and distal third of the stomach. his portion
of the stomach is easily evaluated using the liver as an acoustic
window. Distending the stomach with clear luid facilitates
evaluation of the mucosal, submucosal, and muscular layers of
the stomach (Fig. 53.3). Furthermore, gastric peristalsis and
emptying can be evaluated.
FIG. 53.2 Hiatal Hernia. The luid-distended stomach extends through
the esophageal hiatus (arrow).
Normal gastric mucosa, including the muscularis mucosae
and submucosal layers, measures 2 to 3 mm, whereas the outer
circular muscle layer measures between 1 to 2 mm in thickness. 7,8
hese measurements should be obtained with the stomach fully
distended with luid, and the scan should be performed in the
midlongitudinal plane of the stomach or, on cross section,
proximal to the pyloric canal, measuring the single muscle wall
thickness, excluding the mucosa. On cross-sectional imaging, if
the image obtained is too close to the contracted pyloric canal,