How do I cope with managing an imaging department instead of scanning patients?

You were best at the imaging itself, the skill of getting the shot right, positioning a patient, reading what the machine gave back. Now you manage the schedule, the machines, and the people, and the imaging you loved happens mostly in other hands. That is a real loss to feel. The skill has not vanished; it has become something you give away. Every tech you train to get a clean image, every workflow you smooth so patients are handled with care, carries your standards further than your own hands could. You are still shaping the imaging, just through the whole department now instead of one machine. Keep scanning sometimes. Take the hard cases, cover a shift, stay in the room. It keeps your hands skilled and your team respecting that you still know the work. You did not leave the imaging behind by moving up. You just do it through more people now, and directly a little less.