Table 1 Comparison of advantages and disadvantages of various imaging approaches in young infants with achondroplasia

CT

Usually not requiring sedation

Poor delineation of neural structures

Only study method for which there are diagnosis-specific standards (FM size) [122]

Substantial radiation exposure, particularly if not performed in children’s facility

Only study method for which prospective assessment of value in ascertaining risk is available [8]

In substantial minority, along with results of other non-radiologic studies, will lead to MRI subsequently

In our experience, about 20% of those following protocol including CT will go on to MRI

MRI

Excellent delineation of neural structures

Virtually always requires sedation or anesthesia

Because of respiratory concerns present in most infants with achondroplasia, anesthesia is usually needed

No radiation exposure

No diagnosis-specific standards

Substantial risk of over-reliance in determining if surgery is needed

Although not prevalent in our center, there are many anecdotes of electing to have decompressive surgery based on MRI craniocervical features alone, which we would judge to be non-actionable without other indications

Fast MRI

Fair delineation of neural structures

Detail may be insufficient for decision making

No radiation exposure

No diagnosis-specific standards

No sedation or anesthesia needed

In substantial minority will lead to full MRI before deciding if surgery is needed

At current level of detail, findings on fast MRI will always need to be confirmed by routine MRI if surgery is contemplated

No routine imaging

No sedation or anesthesia

Under-ascertainment of those needing decompression

This is, in my opinion, an unacceptable risk

No radiation exposure

Ignores what prospective and reasonably well controlled trial data as are available to prevent further neurologic injury or sudden death.