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

From: Achondroplasia: a comprehensive clinical review

Study: Advantages Disadvantages Comments
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.