ULTRASOUND OF THE NEONATAL HEAD - Normal

Note: Hover cursor over images for highlighted anatomy.

Normal Sagittal	Normal Coronal
Normal sagittal at the 3rd and 4th ventricles.	Normal anterior coronal neonatal brain. Scan, angling forward of this point as far as possible to the 'bulls-horns' of the sphenoid bone.
Normal parasagittal at the lateral ventricles.	Normal mid-anterior coronal at the sylvian fissures and 3rd ventricle.
Normal far-posterior coronal.	Normal mid coronal view at the level of the brain stem.
Normal coronal view of the lateral ventricles and caudao-thalamic groove.	Normal posterior coronal using a linear array transducer. Zoomed at the level of the trigone of the lateral venticles, visualising the body of the choroid plexii.
The superior sagittal sinus and other vascular channels can be readily assessed with power doppler.	Normal far-posterior coronal.

ULTRASOUND OF THE NEONATAL HEAD PROTOCOL

• Prematurity:
  • Some people discriminate between the terms preterm and premature.
  • Preterm refers to delivering prior to 37weeks whilst a premature infant is one that has not yet reached the level of fetal development that generally allows life outside the womb.
  • The fine network of vessels (the germinal matrix) on the floor of the anterior horn of the lateral ventricles (the ependyma) are extremely fragile.
  • If there is any hypoxic episode, the reactive increase in blood pressure can result in a haemorrhage of these vessels.
  • Usually assessed at day 1 and again at day 7.
• Increased head circumference
• Persisting large fontanelle
• Craniosynostosis (premature closure of sutures)
• Trauma
• Known hypoxia
• Follow up of known pathology
• Failure to thrive
• Suspected intracranial mass or infection

LIMITATIONS

If the anterior fontanel is very small or closed your visibility will be reduced or completely obscured. Even with a large fontanelle, the peripheral extremes of the brain are obscured from view.

EQUIPMENT SELECTION AND TECHNIQUE

Probes:

• Primarily a small footprint, wide sector, mid.-frequency probe is essential.
• Ideally a specific 5-8MHz vector probe however a trans-vaginal probe also provides excellent imaging. (A TV probe can be ergonomically difficult to use for some operators and awkward to ft in a humidicrib.)
• You may also require a high frequency linear array to assess superficial structures and a curvilinear probe for axial trans-temporal images.

Environment:

• A warm room with warm gel.
• If still in high oxygen environment, this should be maintained as much as possible.
• Patient position:
• If still in a humidicrib as a high oxygen environment, the baby must be scanned there. You may need to place a cloth under and/or beside the baby's head to support and immobilize it for the scan.

SCANNING TECHNIQUE

• Use sufficient gel to not require too much transducer pressure.
• Approach is generally via the anterior fontanel. The posterior fontanel can also be used.
• Using the small footprint sector or TV probe:
  • Begin in a coronal plane slowly sweeping from the anterior to the posterior.
  • Rotate 90o to perform sagittal and para-sagittal views.
• Using the high frequency linear probe:
  • Gently scan through the anterior fontanelle in transverse.
  • You should assess the superior sagittal sinus for patency, and the sub-arachnoid space.
  • You will usually be able to scan as deep as the 3rd ventricle.
• Using the 5mHz curvilinear probe: scan through the temple in an axial plane, particularly assessing the opposite subdural region.

WHAT TO LOOK FOR:

• A solid grasp of the intracranial anatomy is vital.
• Also, a thorough understanding of the developmental evolution of the neonatal brain and how it changes between 28weeks and term.
• Essentially, the normal 10week premature brain is relatively smooth, homogenous & devoid of sulci/gyrae.

SAGITTAL

1. Midline (must include corpus callosum the 3rd and 4th ventricles and cerebellum).
2. Parasagiattal to show caudothalamic notch and detail of lateral venticles
3. Far lateral to show periventricular white matter.

CORONAL

1. frontal
2. caudate region
3. series of images caudate to trigone of lateral ventricles
4. occipital region

MEASUREMENTS

• Coronal: frontal horn of lateral ventricles at the foramen of monroe (caudate nucleus)
• Sagittal: trigone of lateral ventricles

BASIC HARD COPY IMAGING

A neonatal head series should include sequential images coronally from anterior to posterior and sagittally from midline left and right.