Preveebral space thickness in adult is

The preveebral component is measured on sagittal imaging as the distance between the anterior border of the veebral body and the air within the pharynx/tracheaNear-normal distribution of thickness in normal patients depending on body build and expected variationPlain radiographs:C2/3: <7 mm and C6/7: <21 mmCT:C1: 8.5 mmC2: 6 mmC3: 7 mmC4/C5: variable due to variable height for cricoid/oesophagusC6: 18 mmC7: 18 mmAccording to age:C20-2 years of age: 7.6 mm3-6 years of age: 8.4 mm7-10 years of age: 6.8 mm11-15 years of age: 6.8 mmC60-2 years of age: 9.0 mm3-6 years of age: 9.8 mm7-10 years of age: 12.1 mm11-15 years of age: 14.5 mm(Ref: Radiology Review ManualBy Wolfgang Dahne 6thEtd, chapter 2)