Spelling (general)

Last revised by Daniel J Bell on 8 Dec 2022

Correct spelling, also known as orthography in formal usage, is crucial to ensuring that the site is easy to read and trusted. There are a number of troublesome examples that are either frequently written incorrectly, misunderstood or where multiple forms are accepted. In the latter case, we just need to choose one form for the sake of uniformity. The term orthography, is the formal term for the system of spelling for any language, although it also encompasses punctuation.

Specific words

Before we begin, it is worth noting that Radiopaedia no longer favors British over American spelling. Read more: British vs American English.

A list of words that have several different forms, with the favored form placed first:

  • follow-up (not follow up or followup)

  • x-ray (not xray or x ray or X ray or Xray)

    • only 'X-ray' when following standard capitalization rules e.g. at the start of a sentence, when in a reference or forming part of a proper noun

Some specific word choices that merit a discussion of their own:


All words with prefixes (e.g. hyper, hypo, intra, extra) should be one word, with a hyphen if a duplicate vowel is present:

  • hypointense

  • extra-axial

  • interpeduncular

The main exception to this rule is the prefix 'non'. 

  • non-specific rather than nonspecific

Generally we do not mandate a hyphen for a double consonant, e.g. we prefer transsphenoidal to trans-sphenoidal.

This does not mean that common English words with duplicate vowels are to be hyphenated of course.

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.