(My spouse was an ultrasound tech for many years.)

The problem with an example like ultrasound is that it's not a passive modality - you don't just take a sweep and then analyze it later. The tech is taking shots and adjusting as they go along to see things better in real time. There's all sorts of potential stuff in way often bowel and bones and you have to work around all that to see what you need to.

A lot of the job is actively analyzing what you're seeing while you're scanning and then going for better shots of the things you see, and having the experience and expertise to get the shots is the same skills required to analyze the images to know what shots to get. It's not just a matter of waving a wand around and then having the rad look at it later.