They don't do walk-ins anymore, only appointments made through a doctor's request. If you have a request, call them to set your appointment, don't expect them to accept you if you haven't called and confirmed your appointment even if your doctor or whomever gives you an appointment time... expect to have the appointment next week.
The way that I've had my scans, your doctor has to order it, then your insurance has to approve it. Once all that has happened, you set an appointment to go in and get the scan. Note that whether or not you get Liberty Pacific depends entirely on your insurance.
Thanks! Your answer is awaiting moderation.