Diagnostic ultrasound ( PDFDrive )

1562 PART V Pediatric Sonography
A B C
D
E F
G H
FIG. 45.59 Infections. (A)-(D) Group B streptococcal meningitis with focal infarction. (A) Coronal sonogram with color Doppler shows
lack of low in the left middle cerebral artery (MCA; arrow); gray-scale imaging alone showed symmetrical, increased echogenicity. (B) Pulsed
Doppler image in the right MCA (opposite side) shows greatly increased diastolic low. (C) Coronal sonogram and (D) computed tomography scan
later show hemorrhage into an infarction with midline shift from left to right. (E) and (F) Coronal anterior and posterior sonograms show left MCA
focal echogenic infarct (calipers), cause unknown, in another premature infant at 2 weeks after birth. (G) and (H) Sagittal sonogram in fetus with
unknown infection, but the pattern of calciication at gray-white junction suggests Zika. Note also the calciications in the corpus callosum (arrows).
(G and H courtesy of I. Castro-Aragon, MD, Boston.)
from the hemorrhage will resolve over time, allowing the tumor
to be visualized.
Spectral and color Doppler imaging can identify vascular
components of the tumor. Follow-up with MRI is then performed
to evaluate the full extent of the neoplasm, assist with diferential
diagnosis, and evaluate for therapeutic approaches. Diferentiating
the histologic type of the neoplasm is not possible, but localizing
the tumor usually allows a diferential diagnosis.
Tumor location in infants younger than 1 year difers from
that in older children and difers by series. 31,221-223 Supratentorial
neoplasms are more common than infratentorial tumors by
approximately 2.5 : 1. Teratomas are the most frequent neoplasms
reported in the irst year of life. Astrocytomas (astrocytic gliomas)
are second in most series, usually arising from the optic chiasm
and nerves or the hypothalamus (Figs. 45.61 and 45.62). Other
neoplasms include atypical teratomas or rhabdoid tumors (rather
than medulloblastomas), primitive neuroectodermal tumors
(PNETs), ependymomas, 224 and choroid plexus papillomas (Fig.
45.63). Sporadic cases of oligodendroglioma, hemangioblastoma,
hemangioma, dermoid cyst, lipoma, primary neuroblastoma,
teratoma, and meningioma have been reported. 224 A few cases
of difuse neonatal hemangiomatosis have been reported,
with numerous hemangiomas of the brain, skin, spinal cord,
liver, and heart. Although these may cause congestive heart
failure, the greatest risk is bleeding into the lesions and possible
disseminated intravascular coagulopathy. hese infants
do not usually live long enough for steroid therapy to cause
involution of the lesions, which typically helps in neonatal
hemangiomas. 225
Common Brain Tumors in First Year of Life
Teratoma
Suprasellar astrocytoma (hypothalamic)
Teratoma or rhabdoid tumor
Ependymoma
Choroid plexus tumor
Cystic Intracranial Lesions
Cystic intracranial lesions are quite common, and ultrasound is
the best method for evaluating such lesions (short of surgical
proof). Fortunately, most cystic masses of the brain are