Best way to clear cache to display updates

Hi, I'm altering the imagefield module to pull files from a library on the server instead of allowing users to upload files.
I have everything working except that the newly added image doesn't appear until I upload another image the normal way, so its a drupal cache issue. I need to either delete the cache or reload it with the new db information when the edit content type page is loaded.

I would prefer not to clear all the cache each time an image is manually added by my code. Is there a way to update the cache when I update the files table? Any suggestions is greatly appreciated.

Thanks