I was diagnosed with runner's knee last September and began physical therapy. Prior to that, I was a 35-40 mile a week runner, 4:06 full marathon, 1:46 half marathon PRs. I did PT for 8 weeks, working core, hips, balance, and quads. Since then, I have continued with the PT exercises 5-6 times per week, roughly 30-45 minutes per day. My knee pain faded some, but never went away. I recently pushed my weekly mileage slowly up to 27, and did a long run of 12. I went up only 2 miles a week. Easy pace of 10:00 per mile. The pain seems to be returning. The pain is not terrible, but it has increased in the last 2 weeks. Any advice would be greatly appreciated. Do I need an MRI? Should I back off the running? Do I need better shoes? I currently use Brooks Adrenaline GTS 10. Thanks for any advice.