Check image exists in folder or not in template helper


I have used cfs in my application for profile image. I want to know about how can i check that which image i uploaded its exists in folder which i specified or not. For example i am uploading my profile image and that image will insert in specified folder and also inserted that image in images table of collectionFS after that i am going to that folder and will delete that image from that folder but that image entry still there in images table of collectionFS so i want to check that image exists or not in folder at template helper and if not exists then i will return url of my default avtar. But how can i check that image exists in folder?

If any question then let me know