Circular Avatar Image for HUD

Hello, I am developing a HUD and my first thought was to put the users player model in the HUD although it had to be fit for a circular container.
I never managed to do that because I think it may be a bit out of my reach as I am very new to GMod lua.
I would like to have the users avatar/profile picture in the HUD. I have gotten as far as putting the Avatar Image in but it is not yet circular. Just square.

This is the simple code I have so far.

As I said that creates a square image instead of a circular image.

If this description is too vague then please just ask and I will supply some images. But for now I think you should understand.
I have looked at another HUD that uses Stencils, maybe if you could tell me something about Stencils that I could use. Remember
this is all being done in one lua file.

Thank you for any help you can give me.

[editline]16th August 2016[/editline]

Never mind I done a bit more searching and found this more recent thread.