there is really no gold standard the other thing is quite often is we've had very great success are reporting fantastic algorithms in a scientific paper and then when you deploy them in a clinical scenario they don't really work that well and if you actually look at scanners they're really only three big scanner manufacturers and when they produce scanners they're not only very in the color as you see here but they really produce slightly different images to a human observer that doesn't really matter but actually turns out to most of