.Net MVC5 Razor ToString Image URL

Perhaps a silly question but trying to display user Avatar images - currently passing in a Guid for the user by @Model.Avatar but need to convert this to the URL string

<img src="~/avatar-images/@Model.Avatar.png"/>

Now apart from the .png on the end this should work? I assume in order perform this as I would like, I need to do a ToString to construct this properly?

Thanks for any advice :)