I think a gown is typically used in those situations for patient comfort, and hygiene reasons as well.  I would have been uncomfortable as well.  This reminds me of a situation I had a few years ago in which I felt a bump in my anus and collected various medical opinions on it, from my GI, a female dermatologist, and then a colorectal surgeon, all of whom told me it was a skin tag and not to do anything about it.  I saw the dermatologist after my GI told me to see one.  She ultimately sent me to a colorectal surgeon for another opinion.  But she creeped me out.  I was a new patient in her office and had never seen or met this woman before. I got her name from a coworker, because my regular dermatologist had just retired.  She brought a female assistant into the room, and did not ask permission or really explain why, mumbling something about her office policy.  I felt like it was because she needed to monitor me, or male patients generally.  I never saw her again.  There was something about it and her explanation that was super artificial and super uncomfortable to me.  I actually never felt that way with a female medical provider, ever, either before or since.

Unlike your radiology tech, who I think just did not care about the embarrassment factor for you or her, the female dermatologist I saw seemed to be all about having a witness in the room to anything that happened.  Maybe she had other male patients who were pervs or made accusations against her, but it felt to me like she needed a monitor in the room. The result was that she lost me as a patient.  It was my first and last visit with her.  It was the only time I ever felt uncomfortable around any doctor, and it was extremely bizarre.  It was like she was telling me right off the bat I don't trust you, and I wanted nothing to do with her after that.

X-rays without a simple gown and only briefs is unacceptable.  Had she needed to position you more correctly she could have asked you to raise the gown above your hips.  Having a chaperone is quite common.  As a nurse in a pediatric ER I was often asked to accompany a male physician into the cubicle when he was examining a female patient on her own.

Jaypea,

I understand you are in the healthcare profession but I am 57 years old, have been a "professional patient" most of my life, and never had to have a "chaperone" in the room until the episode I described above. It's very simple: if a doctor is telling me he or she doesn't trust me as a patient, or else can't trust himself or herself, I do not want to be their patient. I do have the choice of going elsewhere, and I exercised that choice.

I think each situation might be different. I have taken many X-rays while my underwear was on and some with a hospital gown, some even with bra on I believe. II have never been naked though, that would be creepy lol. I believe I have had doctors position me as well when it came to radiology work. I know things can be highly uncomfortable but I would just get everything done to make sure everything is okay. Of course if there is something skecthy going on, definitely speak up and use your voice and talk to a manager/supervisor.