Hey @matthew61

I'm not a doctor or expert, I just have been down this road.....

Unfortunately, this kind of test analysis can't always be very definitive. It points to things that need to be evaluated.
"no pelvic lymphadenopathy or suspicious lesions" is kind of self explanatory, the PI-RADS score is fairly concerning, while the PSA on it's way down is obviously a good sign. It could have been bumped up by any number of things. There is something the MRI is interpreting as a lesion of some kind, it could be anything at this point.

My guess is the docs will likely do one of two things, watch the PSA for a while and see if it continues down and stays down, or, perhaps if your urologist is a bit more aggressive in their treatment approach, they may suggest a biopsy. A lot may depend on your age and general health otherwise.

Unfortunately, it's likely going to be a long weekend of waiting and wondering....
The best thing is probably to keep busy this weekend and try not to think to much about it till you see your doc.

Best of Luck to you!