Erratum to: Pediatr Radiol

DOI 10.1007/s00247-013-2694-1

The original article, unfortunately, contained an error.

The formula for the tortuosity index is missing the “−1”. The correct formula is:

$$ Tortuosity\; Index=\left(\frac{{\displaystyle {\sum}_{i=1}^{n-1}\sqrt{{\left({x}_{i+1}-{x}_i\right)}^2+{\left({y}_{i+1}-{y}_i\right)}^2+{\left({z}_{i+1}-{z}_i\right)}^2}}}{\sqrt{{\left({x}_n-{x}_1\right)}^2+{\left({y}_n-{y}_1\right)}^2+{\left({z}_n-{z}_1\right)}^2}}\kern0.5em -1\right)\times 100\% $$