Yes, you can use an audiologist impression to have your earphones made. It will provide you with a Pro rather than a CSX fit. You can learn more about the difference here.
Please be sure to provide your audiologist with the following instructions. Once you have your impressions have them shipped along with a print out of your order confirmation to:
UE Custom Orders
7700 Gateway Blvd
Newark CA 94560
Please note: If you can't find your confirmation email, please include with your impressions a slip of paper with your name and the email address on your order.