DNR - outpatient facility

Advice needed please. I work as a radiology nurse in an outpatient facility. We are begining to have more & more nuring home patients sent via EMS or private vehicle for routine CT's, xrays, etc. I have asked the administration about our DNR policy, and we really don't have one. I would love to hear how other outpatient facilties deal with this & what is my liability? Thank you in advance.