Lesson of the week: Right sided aortic arch in children with persistent respiratory symptoms

In this paper by Donald Payne and colleagues (16 September, pp 687-8) a mix-up over arrows resulted in an inaccuracy in the labelling of the chest x ray film. The left hand arrow was incorrectly positioned and does not, as stated, point to the right sided arch. The arrow is correctly positioned in the website version of the figure (at http://bmj.com/cgi/content/full/321/7262/687).