01.Go to your wordpress Admin panel -> Settings ->Reading there use there settings:
02. Now head over to your Feedburner feed management section, click on your feed and select edit feed details where at original feed url put http://sitename.com/feed
03. After this at your Feedburner dashboard go to optimize ->Summary burner and make sure that summary burner isn’t active.
Now that everything is done head over to google reader,or any feed reader and check out your feed.It will display the full feed along with images.