An MRI scan can give a good indication if an TRUS biopsy is suitable - a TRUS biopsy can only access some parts of the prostate, so it's not suitable in all cases.
I has a TRUS biopsy first - that was done there and then during a one-stop clinic/consultation. (The MRI report which hadn't turned up in time went on to say, correctly, that a TRUS wasn't suitable in my case, so I had the template biospy later.)