What is the recommended initial imaging modality for brachycephaly and metopic ridge?

Initial Imaging for Brachycephaly and Metopic Ridge

For children with brachycephaly and metopic ridge, clinical examination is the recommended initial diagnostic approach, with imaging reserved only for cases where the clinical examination is equivocal. 1

Clinical Examination as Primary Diagnostic Tool

• Clinical examination by experienced craniofacial specialists is usually sufficient to diagnose plagiocephaly and metopic ridge abnormalities without the need for imaging 1
• A detailed clinical assessment should focus on:
  • Presence of a palpable metopic ridge
  • Head shape abnormalities (brachycephaly, depressed temples)
  • Facial features (hypotelorism, heel-shaped forehead) 2
• Three-dimensional topographical scanning may be useful for baseline assessment of severity but is not required for diagnosis 1

Imaging Recommendations When Clinical Examination is Equivocal

When clinical examination cannot definitively rule out craniosynostosis, the following imaging hierarchy is recommended:

First-line Imaging Options:

• Skull X-rays or ultrasound of the suspect suture is almost always sufficient for definitive diagnosis 1
  • These modalities provide adequate visualization while minimizing radiation exposure
  • Ultrasound can effectively assess suture patency in infants

Second-line Imaging (Only if First-line is Inconclusive):

• CT scan without contrast should be used sparingly and only when necessary to rule out true craniosynostosis 1
  • CT is considered the gold standard for definitive diagnosis but carries radiation risks
  • The benefit of diagnosis must outweigh the radiation exposure risk

Not Recommended:

• MRI has no role in the diagnosis of brachycephaly or metopic ridge abnormalities 1
• Routine CT scanning should be avoided due to radiation exposure concerns 1

Important Clinical Considerations

• Normal physiologic closure of the metopic suture can occur as early as 3 months of age, with complete fusion observed by 9 months in many cases 3
• The presence of a metopic ridge alone does not necessarily indicate true metopic synostosis 4, 5
• There is a documented relationship between positional plagiocephaly and metopic suture abnormalities, with 39% of children with positional plagiocephaly showing some form of metopic suture abnormality 5

Diagnostic Pitfalls to Avoid

• Avoid assuming that early metopic suture closure (3-9 months) automatically indicates pathological metopic synostosis requiring surgical intervention 3
• Be aware that CT scans showing complete metopic suture closure at an early age should not be the decisive factor for surgical intervention without corresponding clinical symptoms 3
• Recognize that altered mechanical forces from supine infant positioning may be associated with early metopic suture ridging distinct from true craniosynostosis 5

By following this evidence-based approach, clinicians can accurately diagnose brachycephaly and metopic ridge abnormalities while minimizing unnecessary imaging and radiation exposure.