The last two posts are pretty much what I've gathered/picked up on while on my radiology elective for the past few weeks.
I'm at a VA so the whole atmosphere is probably quite different from the private world but when with an attending who's reading at a workstation I'll just keep to myself. So far they've been really good about stopping and pointing out findings, some anatomy pimping, or just taking me through a normal image. Just don't sit and say, "What's that?"
And if they bring up something like a Chest XR and ask you to go through it, don't just sit there silently and then try and come up with a diagnosis. Talk it out and explain what you see and your process. They want to see how you approach it, your order of looking at the anatomy and how you describe findings... ex: Chest AP XR of male/female, not rotated, i don't see any tubes or lines, describe mediastinum, what do you see on the L & R heart borders, ribs/bones, lung fields, etc...
Even if you don't know what the diagnosis is you can at least describe what you see.... area of increased attenuation, filling defect on an angiogram, increased T1 signal, etc...
Keep in mind other aspects of radiology that may be more suitable to having a student close by asking questions, such as interventional. Getting to spend a fair bit of time on IR while here and it's been terrific.
Okay, here goes. I don't mind having students look at studies with me. I make it a point to teach when I see something interesting. However, it really bothers me when I pull up a new study and the student immediately blurts out a diagnosis before I have time to evaluate the image myself. I need to develop my own conclusions (I'm still fairly new at this radiology thing, myself), and I don't like being biased by something that someone else says. I also don't like it when a student asks questions about each and every study when there clearly is a large workload (such as on a Monday). Also, I usually save all of my dictations until after finishing read-out with the attending --- so once the attending leaves and I am clearly in the middle of dictating, it's not cool for the student to be asking questions. 
