Diagnostic ultrasound ( PDFDrive )

CHAPTER 53 The Pediatric Gastrointestinal Tract 1855
B
A
C
FIG. 53.38 Henoch-Schönlein Purpura. (A) Slightly hypoechoic, circumferential wall thickening of a single intestinal loop (arrows), with a small
amount of adjacent anechoic free luid (F) in a child with Henoch-Schönlein purpura. Note the normal thin wall of the adjacent bowel loop. (B)
Another child with echogenic, small bowel thickening caused by Henoch-Schönlein purpura (white arrows). Note the normal wall on an adjacent
loop of small bowel (black arrow). (C) Hypoechoic wall thickening in a different child with Henoch-Schönlein purpura.
caused by vasoconstriction, has been suggested as a reliable early
inding on Doppler sonography in NEC infants. 124 Free intraabdominal
air is detectable in infants who have minimal intestinal
gas that has escaped through the perforation. Early free intraperitoneal
gas can be detected most easily along the surface of
the liver or within free intraperitoneal luid. 100 he sonographic
demonstration of complex luid collections with debris can
suggest perforation in such patients 125 (see Fig. 53.40E).
Sonographic Signs of Necrotizing
Enterocolitis
FIG. 53.39 Graft-Versus-Host Disease. Multiple thick-walled small
bowel loops. A thin echogenic layer on the supericial surface of the
mucosa (arrows) represents characteristic ibrinous deposit.
Thickened bowel loops with thinning of loops a late inding
Echogenic foci caused by portal venous air
Echogenic ring of intramural pneumatosis
Pericholecystic hyperechogenicity
Increased low in superior mesenteric artery and celiac
artery
Complex luid collections with perforation of bowel
or as a granular echogenic ring within the bowel wall with
posterior reverberation when more difuse. 99,100 Intramural gas
will not change with peristalsis or shit with change in positioning
of the patient, which helps distinguish intramural from intraluminal
gas. In addition, sonography can detect small amounts of
gas within the portal venous system, which appear as small
echogenic mobile foci within the liver, well before the gas is
evident on plain ilms. 120-122 he patchy pattern with large amounts
of mobile gas within the liver can be quite striking. Pericholecystic
hyperechogenicity has also been described in infants with NEC. 123
he most serious complication is bowel necrosis with perforation.
Increased low velocity in the splanchnic arteries, most likely
Appendicitis
Ultrasound is now the recommended initial examination for
those suspected of having appendicitis. 126 MRI is being used
more oten for those with large body habitus when ultrasound
is unsuccessful. 127 Although CT is efective in diagnosing appendicitis,
the growing trend to avoid unnecessary ionizing radiation
is causing a shit away from the frequent use of CT. 128,129
When appendicitis is not found, ultrasound oten can help
to suggest or conirm an alternative diagnosis. 130 In the end, the
diagnostic approach to the acute abdomen remains a surgical
management decision, but sonography is increasingly used to
help diagnose appendicitis and to help manage postoperative
complications.