Inclusion Criteria:  • Healthy children, according to the American Society of Anesthesiologists (ASA) risk classification. Children with ASA risk class 1 or 2 were selected by the anesthesiologist as suitable for radiographer handled sedation with Dexmedetomidine.  Exclusion Criteria:  Children with significant comorbidity (ASA risk class 3 or 4) that were deemed to need presence of an anesthesia team (anesthesiologist plus certified anesthesia nurse) for safety reasons. Children that due to the specific nature of the MRI scan would need a general anesthetic to provide a secure airway (e.g., laryngeal mask airway or endotracheal intubation) during the scan (e.g., mild neck manipulation to assess cervical instability in Mb Down patients, multiple different MRI investigations requested or need for apnea). Children that present minimal cold symptoms the day of imaging.