Diagnostic ultrasound ( PDFDrive )

CHAPTER 49 The Pediatric Spinal Canal 1695
HEMORRHAGE AND INFECTION
Hemorrhage within the vertebral canal can occur in newborns
in association with trauma, such as a birth injury, or with an
invasive procedure such as failed lumbar puncture (“bloody
taps”). Hemorrhage from birth trauma can be centered at any
vertebral level. Hemorrhage related to lumbar puncture is
originally centered at the point of needle placement but can
extend superiorly and inferiorly for some distance. hese primarily
epidural collections can be visualized acutely as echogenic luid
that becomes heterogeneous and then anechoic in appearance,
resolving in 2 to 4 days. 45,115 (Fig. 49.31). Injury to the spinal
cord itself is also visible with ultrasound as a hyperechoic focus
in the acute phase. 116 Echogenic debris within the subarachnoid
space is sometimes visible with ultrasound ater lumbar puncture
(Fig. 49.32). his may represent hemorrhage from the trauma
of the procedure or may be caused by redistribution of hemorrhage
originally found in the cerebral ventricles of infants with known
intraventricular hemorrhage. 117
Ultrasound is useful for guiding percutaneous lumbar puncture
118 and for guiding anesthesiologists for caudal anesthesia
in infants and neonates. 119 With a high-resolution transducer,
the spinal needle can be followed from the skin to the thecal sac
using midline sagittal scanning in the neonate and young infant
and parasagittal scanning in the older infant and child. 45,120
he importance of prompt recognition and treatment of
epidural abscesses is well documented in the literature. 121 In the
newborn and infant period, ultrasound is useful in detecting
such collections. 122,123 his is particularly true if the infant is
medically unstable and transfer to the MRI suite is deemed too
risky. It is important to scan the entire length of the vertebral
column and to pay special attention to the integrity of the vertebral
bodies in these patients.
ARACHNOID CYSTS
Arachnoid cysts are infrequently found in infants, children and
young adults. hey can be incidental indings or they can cause
A
B
C
D
FIG. 49.31 Collections After Failed Lumbar Puncture. Epidural collection. (A) and (B) Sagittal views of the lumbar spine show the distal
cord (C). There is a large hypoechoic epidural collection (arrows). The dura is the echogenic horizontal line deep to the collection. There is a small
amount of subarachnoid luid surrounding the nerve roots in the cauda equina (CE). Subdural collection. (C) Sagittal view of the lumbar spine
shows the distal cord (C) and cauda equina (CE). There is a small subdural luid collection seen between the dura and the arachnoid (arrow).
(D) Transverse view of the subdural collection conirms location of the luid (arrow) below the dura. Note the fat (*) in the epidural space and the
nerve roots in the cauda equina (CE).