Comparison of the skin-to-epidural space distance at the thoracic and lumbar levels in children using magnetic resonance imaging

The distance from the skin to the epidural space is not constant at various vertebral levels. At the levels measured, it was greatest at the lumbar level and at least at the thoracic level of T₉₋₁₀. A single predictive formula was not applicable for calculating the approximate SED at all vertebral levels.