Prostatitis is different than a UTI, can be difficult to diagnose, and can spike PSA quickly. Have you had any symptoms down there or any unexplained sickness of any sort? Usually they try to get a semen sample to check out prostatitis further or possibly scans.
https://www.pcf.org/c/prostatitis-misdiagnosed-and-misunderstood/That being said, after my annual PSA jumped (4-> 5), I saw the urologist and he recommended the MRI scan first to see what might be there prior to doing a biopsy. It show two lesions and he did the MRI/ultrasound guided fusion biopsy with a couple of targeted cores. The biopsy found want it was looking for and the rest is history.
I think getting the MRI before seeing the U of Iowa doctors might be a good idea but please check with them first unless they ordered the test. They certainly should know about
your last PSA drop.
Your question about
being 70 years old and an MRI would be easier if you were 80. At age 70, I hope you are planning to beat the odds and live to 90+ so catching things early still applies to you. If not, you have a lot more latitude with medical recommendations.