Range of creep agro?

Hi everyone

In a recent game, I had that really strange case where the ennemy ryze, despise beeing in a large group of friendly minion (and i mean right inside of it), never drew the agro on him when he cast his spell on me.

Always thought that minion agro had a pretty big range but, it appears that ryze spell range ( who is small btw) is bigger than that.

Did someone have an idea of what kind of max range that agro is? ( with image or spell like range)