Theory and practice : how much contrast for myelography?

A questionnaire sent to members of the British Society of Neuroradiologists revealed that the majority of practitioners will, when necessary, inject more than 3 g of iodine during myelography with iohexol or iopamidol. The 3 g limit recommended by the contrast medium manufacturers is not based upon scientific studies involving these media, and it is the experience of British neuroradiologists that larger amounts of modern contrast agents can be used without an increase in post myelography complications. There is, therefore, a need for a controlled trial to assess the question of the most appropriate dose of contrast medium in myelography.