Complex sentence: The X-rays reveal Lassie has a brain injury that requires expert surgery and only one man can do it, Dr. Watkins, a research veterinarian at the state college.
Split into simpler sentences: The X-rays reveal Lassie has a brain injury that can be remedied with expert surgery. It's a delicate operation and only one man can do it, Dr. Watkins, a research veterinarian at the state college.