The last outpatient office that I worked in had this same requirement. It was a pain and tests were often delayed, but it was required. Essentially we had to identify the providers that were the most willing and try to go to them first. If they were unavailable we would go to the PA's, and finally the less agreeable providers and explain that no one else was available. It's also really important that leadership/management informs the providers that this change is required and they need to assist. One of the ways we attempted to get ahead of the clock was consenting 2 or 3 nuclear patients at the same time. Didn't always work, but if we could manipulate patient arrival times we tried to. It's a pain and providers don't make it easy, but it's doable.