Ultrasound image Normal sagittal at the 3rd and 4th ventricles.
Ultrasound image Normal anterior coronal neonatal brain. Scan, angling forward of this point as far as possible to the ‘bulls-horns’ of the sphenoid bone.
Ultrasound image Normal parasagittal at the lateral ventricles.
Ultrasound image Normal mid-anterior coronal at the sylvian fissures and 3rd ventricle.
Ultrasound image Normal sagittal far-lateral.
Ultrasound image Normal mid coronal view at the level of the brain stem.
Ultrasound image Normal coronal view of the lateral ventricles and caudao-thalamic groove.
Ultrasound image 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.
Ultrasound image The superior sagittal sinus and other vascular channels can be readily assessed with power doppler.
Ultrasound image Normal far-posterior coronal.
Role of Ultrasound
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)
Follow up of known pathology
Failure to thrive
Suspected intracranial mass or infection
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.
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.
Midline (must include corpus callosum the 3rd and 4th ventricles and cerebellum).
Parasagiattal to show caudothalamic notch and detail of lateral venticles
Far lateral to show periventricular white matter.
series of images caudate to trigone of lateral ventricles
Coronal: frontal horn of lateral ventricles at the foramen of monroe (caudate nucleus)
Sagittal: trigone of lateral ventricles
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.
A warm room with warm gel.
If still in high oxygen environment, this should be maintained as much as possible.
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.
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.
Basic Hardcopy Imaging
A neonatal head series should include sequential images coronally from anterior to posterior and sagittally from midline left and right.
Document the normal anatomy. Any pathology found in 2 planes, including measurements and any vascularity.