Your best bet for a referral is to ask your GI doc. Also, a nearby University Hospital is always a good resource. I will ask my team if they have a suggestion when I see them at the end of the month.
I have 3 sons. Two of my sons were diagnosed from ultra sounds and an MRI while going through the evaluation process to be my live donor. I knew that the chances were one of them would have PLD, I was shocked when two of them were diagnosed. My oldest son has a few cysts but not PLD. They are all healthy young men. Their doctors will monitor but have no concerns at this time.
I was diagnosed by ultrasound when my Primary doc ordered it for complaints of discomfort and pain in my abdomen. We had no idea that there was a family history of PLD. When I was diagnosed and began asking questions, we discovered that it was mentioned in a report from an MRI my dad had but it wasn't a problem so he had never shared.