Ladan and Laleh Bijani: Iranian conjoined twin sisters

But image guidance also played an important role: It allowed Goh and his team to visualize every step of the surgery before they got into the operating room. It boosted their confidence, giving them faith in their ability to do something that others had said was impossible. There's a downside, though. The added self-assurance can backfire, cautions Ramin Shahidi, who invented the Stanford imaging system. "Image guidance makes some surgeons better," he says. "But it can make others braver."