Raycast collision for 2D?

Hi,

I am making a 2d game and in order to do that I have images with transparent background on a plane. Right now since it is a shooting game, I am using raycast to detect when it collides with the plane. However, is there a better way to do it? At the moment, the collision still occurs as long as the player "shoots" the plane, i.e. around the 2d image object, not necessary on it.