Delete all image signatures using regular expressions?

[ibuddy]

Is there anyway for a mysql command using reg expressions that I can run to wipe out all [img] bbcode images in signatures?

I just installed this new mod that limits peoples size of images for signatures, so I have it set to 500x150....but it doesnt take effect to the current image signatures that are bigger than those dimensions. So what I wanted to do was wipe out all the image signatures, I know how to wipe out all signatures but only want to wipe out [img] bbcode tags in everyones signature so when they set their new image in their signature it will use the new mod and restrict larger images.