It usually doesn't matter how many times a particular graphic is used. Any time a single user logs on to a site. He can look at all the pages of the site, but it still equals only one user session. Any time a viewer looks at a particular page. This is more meaningful than a hit.
Most web servers maintain access logs.
This log will contain information about which pages have been viewed how many times, what page referred the web surfer to your page, what time they came in, any errors encountered if any. Ask your ISP to set this up on your site. Most good web hosting services will offer some form of statistical analysis.