Background

Cranial ultrasonography (CUS) is non-invasive imaging procedure that uses high-frequency sound waves to visualize brain structures.

It is considered as safe, portable, cost-effective, and ideal for diagnosis of pediatric and neonate patients to understand their intracranial pathology.

Ultrasound technology introduced in the 1940s while CUS was established till 1970s as a diagnostic tool till.

Transducer advancements and Doppler techniques these factors are responsible to increase accuracy of cranial ultrasonography.

Main advantages of CUS are:

Non-invasive and Safe

Bedside Capability

Real-time Imaging

CUS is effective in the diagnosis and management of intracranial abnormalities in neonatal and pediatric patient.

It is generally used as first-line imaging procedure for brain abnormalities in neonates under clinical management.

Indications

Premature Infants: To assess neurological health in high-risk premature infants.

Neonatal Neurological Symptoms: To evaluate underlying causes of neurological symptoms.

e.g. seizures, abnormal head growth

Congenital Brain Anomalies: CUS is a sensitive tool for the detection and evaluation of congenital abnormalities including holoprosencephaly and agenesis of the corpus callosum.

Suspected Infections: CUS also identifies complications associated with CNS infections such as meningitis and abscess formation.

Cerebral Vascular Abnormalities: It allows evaluation of cerebral blood flow to detect arteriovenous malformations.

Intracranial Masses: It may detect space-occupying lesions such as cysts and tumors.

Contraindications

Absence of Acoustic Windows

Severe Cranial Deformities

Severe Scalp or Cranial Injuries

Post-Fontanelle Closure

Inadequate Patient Stability

Obesity or thick scalp may impact image quality and diagnostic accuracy by reducing sound wave penetration clarity.

Outcomes

Early IVH grading and ischemic injury detection guide prognosis and management in premature infants.

Identifying structural anomalies helps genetic counselling and long-term care planning effectively.

Regular assessments evaluate ventricular size and intervention effectiveness, guiding surgical decision-making.

Cerebral edema detection predicts outcomes and guides hypothermia treatment decisions.

Doppler imaging helps adjust ventilation and perfusion in neonates.

CUS is a quick bedside imaging tool in NICUs, that reduce the late diagnosis over MRI or CT.

Equipment required

Ultrasound Machine

Transducers

Acoustic Gel

Wipes and Cleaning Material

Recording and Reporting Tools

Patient Preparation

Confirm clinical reason for scan of IVH screening or hydrocephalus evaluation.

Relevant history should be reviewed including birth details, previous imaging, and neurological symptoms.

Informed Consent:

Procedure is painless, non-invasive explain this to parents along with its purpose, safety, and duration.

Explain the procedure’s risks and potential complications clearly to the patient or guardians.

Patient Positioning

Patients should be calm or asleep thus feeding before the scan may increase calmness in neonates.

Position the infant supine and gently stabilize the head with a hand or soft support.

The anterior fontanelle is primary, but others serve for specific views during examinations.

Evaluation of cranial ultrasonography in neonates

Equipment Setup

Use a high-resolution ultrasound machine with high-frequency transducers i.e.,5 to 10 MHz for neonates.

Use a thin layer of water-based ultrasound gel to increase sound wave transmission.

Scanning Procedure:

Acoustic Windows

CUS indicated for the open fontanelles and thin cranial bones as natural acoustic windows. Common acoustic windows include:

Anterior Fontanelle

Posterior Fontanelle

Mastoid Fontanelle

Temporal Bone

Systematic scanning is performed in three standard planes as follows:

Sagittal Plane

Coronal Plane

Axial Plane

Imaging Protocol:

Optimize factors like depth and focus settings for clear images.

Adjust transducer angle gently to avoid losing any important anatomical details.

Post-Scanning:

Wipe off ultrasound gel from the infant’s head as cleaning part. Finally disinfect the transducer as per infection control protocols.

Complications

Patient Discomfort

Skin Irritation

Artifacts Affecting Diagnosis

Overheating of the Probe

Cross-Infection Risk

Inadequate Imaging

References

Cranial ultrasound for beginners – PMC

References

Cranial ultrasound for beginners – PMC