Glossary term:

Oedema

A build-up of water within body tissues, essentially “waterlogging”. It may be seen as swollen ankles in elderly people with a degree of heart failure, or even in healthy people after long-haul flights. The brain may also become swollen with oedema following a head injury or stroke. The spinal cord may appear oedematous on MR imaging above or below a syringomyelia cavity. A volume of “pre-syrinx” oedema in the spinal cord may foretell its likely evolution into a syringomyelia cavity.