Hi Simon, Lyn is right the doctors tell you all you need to know, they won't be hiding anything.
My MRI revealed areas of suspicion, and also identified a breach of the capsule, so they may not know from an MRI if it is cancer, but they can tell if there are areas of suspicion outside the prostate and I think the mri can detect if lymph nodes are involved. So if nothing has been said about lymph nodes or areas of suspicion outside, I doubt there is anything to say.
Things like prostate volume are interesting to geeks like me (and Andy62), but would just be glossed over by your consultant at this stage.
All doctors know you can ask for your medical records so they won't hide anything from you, if they omit anything in a meeting it is probably because it is not important.
It would be silly for me to say "don't worry" anyone going for a cancer test will be worried. But I'm feeling silly and based on the evidence so far, I'll say "don't worry".