Thanks everyone for many great ideas, this has been very helpful.
USAFblue, I'm in the Air Force myself. Your story is very special, thank you for sharing it.
What a coincidence!!! Are you in a civilian or a military residency?
Can you do some "art" work? Do you know anyone who could help you? Maybe you could look up all the coolest, funniest or most educative radiological images that have something to do with your PD teaching you, and you could have someone make like a funny but also sentimental scrapbook or a tableau... With a little note under each of them to make your PD laugh or get a little sentimental tear in his/her eye... You could add some pics of you and the PD at work... If you can't do it yourself, but you are USAF, I bet you could find someone on a military base to help you with that project... The best way to find someone like that is going to a craft/scrapbook store nearest to any base and they will give you contact info of people who could do a great job for you if it isn't possible to do it yourself!
You could even take like one radiology image, something special, like one that you both laughed about a lot, and have it framed with funny notes... The way it's done, nice frame, nice background - fitting the office your PD works at...It can be a very nice decorative element for that office... Something you look at and you smile... If you have the material and the ideas what you would want to put in it, then a picture framing workshop/store can do an awesome job for you in putting it all together in a very nice gift....
You could go goofy, take a chest X-ray of yourself, leave your name and everything on a printed version, put your and the PD's picture on the heart shadow, and write something funny about thanking him with all your heart...
Sorry if that sounds stupid... I am just brainstorming with you here... I'd hope it could give you some ideas... Lead to better ones in your head...
P.S. Would you mind sharing your perspective on being a USAF doc? Maybe in a PM? I am really interested in that aspect, since my husband plans to "stay in for a longer while"