@plynhky
Determining pvr does require getting an ultrasound. After my primary care doc referred me to a urologist who does aquablation the urologist’s office did a screening that included a urine flow test that measured volume and flow rate followed by an ultrasound to test for pvr.
Based on that visit, the urologist scoped my prostate and also used a transurethral ultrasound to determine the size and shape of my prostate. Based on that scoping snd ultrasound he determined aquablation was appropriate.
Another simple thing to try to see if you might have a pvr is issue is to try double voiding. Wait 10 to 15 minutes and try going again. If you are able to go quite a bit, like a 100 ml or more, it might indicate an issue.