PET/CT Site Planning & Installation Guide
PET/CT site planning is the most complex of any imaging modality. A facility must accommodate the scanner with its powerful CT subsystem, the radiopharmaceuticals that make positron imaging possible, and the unique reality that injected patients themselves become temporary radiation sources for 6 to 8 hours after administration.
Higher Energy, Heavier Shielding
511 keV changes everything
PET imaging uses 511 keV annihilation photons — far more penetrating than the 120–150 kVp X-rays of the CT subsystem. PET/CT room shielding is typically two to three times what a standalone CT room requires. A planner who has only designed CT facilities will underestimate PET/CT shielding by a large margin.
1. The Four Critical Spaces
- Scanner Room — PET/CT gantry, table, lead-lined doors and lead-glass window; heavy floor loads from equipment and shielding mass.
- Hot Lab / Radiopharmacy — where unit doses are received, assayed, drawn, and dispensed; the heaviest shielding in the facility per square foot.
- Uptake / Resting Rooms — where injected patients rest 60–90 minutes; substantial wall and door shielding because the patient is a radiation source.
- Control & Equipment Rooms — operator console, workstations, electronics and cooling, adjacent with clear sight lines to the patient.
2. Scanner Room Design
The scanner room is the largest single space. Plan for a gantry footprint of roughly 7 ft wide by 8 ft deep plus 6–8 ft of table travel. Floor loading is a real constraint: the scanner weighs 6,000–9,000 lb and the lead shielding can add another 5,000–15,000 lb — total dead load on the slab can exceed 25,000 lb.
| Space | Recommended |
|---|---|
| Scanner Room — Minimum | 18' x 20' (~360 sq ft) |
| Scanner Room — Typical | 20' x 24' to 24' x 32' |
| Clearance — bed sides / foot | 4 ft each side; 4 ft for table travel |
| Ceiling Height | 8'-6″ clear min; 9'-0″ preferred |
3. Hot Lab / Radiopharmacy
The hot lab is the operational heart of the facility — every dose passes through it. It includes dose receipt/storage, an assay station with the dose calibrator, a dispensing area, a shielded fume hood, decay-in-storage for short-half-life waste, handwashing, and a shielded pass-through window to the scanner suite.
| Equipment | Description |
|---|---|
| Dose Calibrator | Capintec CRC-15 or equivalent, shielded |
| Shielded Fume Hood | Lead-lined, lead-glass window, ducted to exterior |
| L-Block Shields | ~2″ lead with leaded glass for drawing doses |
| Syringe Carriers / Shields | Lead/tungsten transport and injection shields |
| Survey Meter / Decay Storage | Area surveys; shielded decay-in-storage waste |
Hot lab walls and doors typically run 0.5–1.0″ lead equivalent — the heaviest in the facility per square foot. F-18 has a 110-minute half-life, so most waste decays to background within 24 hours via decay-in-storage.
4. Uptake & Patient Resting Rooms
After injection the patient rests quietly 60–90 minutes while the tracer distributes. Uptake-room count is the throughput bottleneck: a facility scanning 8–10 patients/day typically needs at least 3 uptake rooms (higher-volume sites need 4–6). Rooms are kept warm, dim, and calm — cold or activity drives background muscle and brown-fat uptake that obscures lesions.
Uptake-room walls and doors typically run 0.25–0.75″ lead equivalent. A private shielded toilet adjacent to the suite is strongly recommended — it keeps injected patients out of public corridors and isolates FDG-contaminated urine. Audio/video monitoring lets staff watch patients without adding occupational dose.
5. Radiation Shielding for PET/CT
Shielding must be calculated by a qualified medical physicist. The 511 keV photons require five to ten times the lead thickness of a diagnostic CT room; concrete and steel are viable, sometimes more cost-effective at PET/CT thicknesses.
| Element | Typical PET/CT Range |
|---|---|
| Scanner Room — Walls | 0.5″–1.0″ lead (or 8″–12″ concrete) |
| Scanner Room — Doors | 0.5″–0.75″ lead equivalent |
| Hot Lab — Walls & Doors | 0.5″–1.0″ lead equivalent |
| Uptake Rooms | 0.25″–0.75″ lead equivalent |
| Viewing Window | ≥ 4 mm lead-equivalent glass |
The physicist’s report drives everything
Every state radiation control program requires a stamped shielding plan before a PET/CT installation can be authorized for patient use. Budget 4 to 8 weeks for this process and complete it before construction begins.
6. Patient Flow & One-Way Workflow
PET/CT facilities are designed around a one-way flow loop: once injected, a patient should never share corridor space with pre-injection patients, the public, or staff who do not need to be near them. The standard flow runs reception → prep and injection → uptake room → private toilet → short shielded transfer → scanner → discharge along a path that does not loop back past pre-injection patients. Where a strict loop is impossible, time-separation scheduling is the next-best design.
7. Electrical, Grounding & HVAC
PET/CT combines a multi-slice CT’s electrical demand with the PET detector and processing systems. Strict equipotential grounding is essential — even small ground-potential differences inject noise into the sensitive PET electronics.
| Item | Typical Requirement |
|---|---|
| Main Service | 480V three-phase (some 208V), dedicated |
| Continuous Load | 50–90 kVA |
| Peak Load | Up to 150 kVA during CT acquisitions |
| Scanner Room Temp | 64°F – 75°F, ±2°F |
| Equipment Room Heat Load | 40,000–70,000 BTU/hr |
The hot lab needs its own ventilation: slight negative pressure to corridors, 10–15 air changes per hour, and exhaust through HEPA filtration to the exterior — never recirculated into the facility.
8. IT, PACS & Project Timeline
A whole-body PET/CT exam generates 800 MB–2 GB of data, so the suite needs fiber/CAT6, gigabit-plus end-to-end speed, DICOM compliance for both CT and PET, and modality-worklist integration. PET/CT studies retain for years for oncology follow-up, so verify archive capacity.
From signed contract to first patient scan, expect 10 to 16 weeks for a refurbished PET/CT — longer than CT, driven by shielding, hot-lab construction, and the radiopharmaceutical license: survey, physicist report, and license application (wk 1–3), construction and shielding (wk 5–10), scanner delivery and hot-lab commissioning (wk 10–13), physicist survey and license activation (wk 12–15), training and first patient scan (wk 14–16).
Ready to plan your PET/CT project?
Our project management team will walk your site, identify the considerations specific to your space, and build a realistic timeline and budget around your facility.