Nuclear medicine is the one imaging service that brings unsealed radioactive material into the building — radiopharmaceuticals that are received, stored, drawn into doses, injected into patients, and then walk the corridors as ambulatory radiation sources. That single fact reshapes the design problem: the room program, shielding, ventilation, plumbing, regulatory licensing, and operational workflow are all driven by contamination control and radiation dose rather than by the imaging equipment alone. This article covers the gamma-camera/SPECT and PET/PET-CT imaging rooms, the radiopharmacy ("hot lab"), the uptake and hot-toilet rooms, and the licensing and building-systems requirements that make the service operable. Deep radiation-shielding methodology and the medical physicist's role are treated as their own Article; here the shielding discussion stays scoped to what is distinctive about radiopharmaceutical sources and PET energies.
Most imaging modalities create radiation only when energized — switch off the CT or fluoroscope and the hazard is gone. Nuclear medicine is the inverse. The hazard is a quantity of unsealed radioactive material that decays continuously, cannot be turned off, emits in all directions, and becomes a contamination source the moment a vial leaks or a syringe drips.
The design consequences cascade from that:
Everything below is a working-out of these four facts.
Nuclear medicine sits at the intersection of radiation-materials regulation, facility-design guidance, building/fire/life-safety codes, and accreditation. The principal bodies and documents:
| Domain | Authority / standard | What it governs here |
|---|---|---|
| Radioactive materials | NRC (10 CFR Parts 20, 30, 35) or Agreement State radiation-control program | Possession license, dose limits, security/storage of byproduct material, surveys, waste, authorized users. Agreement States regulate in lieu of the NRC — confirm which applies at the site. |
| Facility design | FGI Guidelines for Design and Construction of Hospital / Outpatient Facilities | Required room set, sizing, finishes, the imaging/nuclear-medicine functional program; references ventilation and physicist-led shielding. |
| Ventilation | ASHRAE 170 (Ventilation of Health Care Facilities) | Air-change rates, pressure relationships, exhaust for the hot lab and PET dose rooms. |
| Shielding methodology | NCRP Reports (e.g. NCRP 49, 147, 151, and PET-specific guidance) | The physicist's structural-shielding design basis (covered in the radiation-shielding Article). |
| Radiopharmaceutical compounding | USP <797> (sterile) and USP <825> (radiopharmaceuticals — preparation, compounding, dispensing, repackaging) | Sterile-compounding and radiopharmacy practice standards; drive hood/biosafety-cabinet selection, room cleanliness, and workflow. |
| Electrical / fire / life safety | NEC (NFPA 70) Art. 517, NFPA 99, NFPA 101, NFPA 110/72 | Power categories, essential electrical system, egress, emergency power, alarms — as for any clinical/imaging space. |
| Building/occupancy | IBC, local AHJ | Occupancy classification, structural, accessibility coordination. |
| Accessibility | ADA / ABA | Accessible imaging/injection/toilet rooms and routes. |
| Accreditation | CMS Conditions of Participation; TJC or DNV; ACR / IAC accreditation of the imaging program | Environment-of-care, radiation-safety program, equipment QA, technologist credentialing tied to operations. |
| In-house cyclotron / radiopharmacy (if present) | NRC/Agreement State, FDA (cGMP if producing drugs for distribution), state pharmacy board | Production of PET isotopes/tracers on site — a different, heavier regulatory and shielding tier. |
A key planning rule: engage a qualified medical/health physicist and the radiation-safety officer (RSO) at programming, not at construction documents. Shielding, room placement, and the license application are interdependent, and the physicist's shielding report is a design input the architect and structural engineer build to.
A full-service department typically includes the following functional spaces. Not every site needs all of them, but the dose-handling chain — receive, store, prepare, administer, uptake, image, void, survey, waste — must be complete and one-directional where possible.
Imaging rooms
Radiopharmaceutical handling