Put the image you want to link from on the page, following these steps.

Then embed the image markup in the link markup. For example, to link from the caBIG® logo to the caBIG website, you would type this markup, assuming the caBIG logo is attached to the page:

\[\!caBIGlogoR.jpg\!\|https://cabig.nci.nih.gov/\]

The result looks like this:

To link to another page in the wiki, use the markup explained on this page.

Further tips are available on the Atlassian website.