Diagnostic ultrasound ( PDFDrive )

1554 PART V Pediatric Sonography
A
B
C
D
FIG. 45.51 Cerebral Edema. (A) and (B) Coronal sonograms; (C) and (D) sagittal sonograms. Severe cerebral edema has caused effacement
and silhouetting of the sulci from acute, near-total intrauterine asphyxia after placental abruption. Diffuse increased echogenicity from edema
obscures sulci. Ventricles are slitlike because of the severe edema.
secondary to atrophy. 31 Enlarged extraaxial luid spaces also
develop as a consequence of the atrophic changes. he head
circumference is very helpful to distinguish difuse atrophy from
hydrocephalus, because the head circumference is normal to
small in patients who have undergone difuse brain atrophy.
Depending on the type of insult, generalized brain atrophy or
focal areas of porencephaly or encephalomalacia may occur. With
acute near-total intrauterine asphyxia in the newborn, an
unusual pattern of basal ganglia damage with sparing of the
cerebral cortex and white matter has been reported. his may
be diicult to diagnose with ultrasound if it is not hemorrhagic
until late changes of atrophy develop 31 (Fig. 45.52).
Sonography can detect these complications of hypoxic-ischemic
events, but MRI is more sensitive to the full extent of the insult
near the cortical surface. 31,170 To optimize ultrasound imaging
of the term neonatal brain, Daneman and colleagues 171 used
higher frequencies (8-17 MHz) with multiple focal planes in
near-ield, midield, and far-ield magniied views with spectral
and color Doppler ultrasound, searching for abnormal resistive
indices on spectral Doppler ultrasound. hey also emphasized
the need to perform the ultrasound examination within 2 hours
of MRI for an accurate comparison. Special features to be evaluated
on every ultrasound study in neonates with hypoxic-ischemic
insult should include gray matter–white matter diferentiation